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30 files changed, 8372 insertions, 3268 deletions
diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst index bdf1963ba6ba..a5ea2cb0082b 100644 --- a/Documentation/trace/events.rst +++ b/Documentation/trace/events.rst @@ -520,1550 +520,4 @@ The following commands are supported: totals derived from one or more trace event format fields and/or event counts (hitcount). - The format of a hist trigger is as follows:: - - hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>] - [:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue] - [:clear][:name=histname1] [if <filter>] - - When a matching event is hit, an entry is added to a hash table - using the key(s) and value(s) named. Keys and values correspond to - fields in the event's format description. Values must correspond to - numeric fields - on an event hit, the value(s) will be added to a - sum kept for that field. The special string 'hitcount' can be used - in place of an explicit value field - this is simply a count of - event hits. If 'values' isn't specified, an implicit 'hitcount' - value will be automatically created and used as the only value. - Keys can be any field, or the special string 'stacktrace', which - will use the event's kernel stacktrace as the key. The keywords - 'keys' or 'key' can be used to specify keys, and the keywords - 'values', 'vals', or 'val' can be used to specify values. Compound - keys consisting of up to two fields can be specified by the 'keys' - keyword. Hashing a compound key produces a unique entry in the - table for each unique combination of component keys, and can be - useful for providing more fine-grained summaries of event data. - Additionally, sort keys consisting of up to two fields can be - specified by the 'sort' keyword. If more than one field is - specified, the result will be a 'sort within a sort': the first key - is taken to be the primary sort key and the second the secondary - key. If a hist trigger is given a name using the 'name' parameter, - its histogram data will be shared with other triggers of the same - name, and trigger hits will update this common data. Only triggers - with 'compatible' fields can be combined in this way; triggers are - 'compatible' if the fields named in the trigger share the same - number and type of fields and those fields also have the same names. - Note that any two events always share the compatible 'hitcount' and - 'stacktrace' fields and can therefore be combined using those - fields, however pointless that may be. - - 'hist' triggers add a 'hist' file to each event's subdirectory. - Reading the 'hist' file for the event will dump the hash table in - its entirety to stdout. If there are multiple hist triggers - attached to an event, there will be a table for each trigger in the - output. The table displayed for a named trigger will be the same as - any other instance having the same name. Each printed hash table - entry is a simple list of the keys and values comprising the entry; - keys are printed first and are delineated by curly braces, and are - followed by the set of value fields for the entry. By default, - numeric fields are displayed as base-10 integers. This can be - modified by appending any of the following modifiers to the field - name: - - - .hex display a number as a hex value - - .sym display an address as a symbol - - .sym-offset display an address as a symbol and offset - - .syscall display a syscall id as a system call name - - .execname display a common_pid as a program name - - Note that in general the semantics of a given field aren't - interpreted when applying a modifier to it, but there are some - restrictions to be aware of in this regard: - - - only the 'hex' modifier can be used for values (because values - are essentially sums, and the other modifiers don't make sense - in that context). - - the 'execname' modifier can only be used on a 'common_pid'. The - reason for this is that the execname is simply the 'comm' value - saved for the 'current' process when an event was triggered, - which is the same as the common_pid value saved by the event - tracing code. Trying to apply that comm value to other pid - values wouldn't be correct, and typically events that care save - pid-specific comm fields in the event itself. - - A typical usage scenario would be the following to enable a hist - trigger, read its current contents, and then turn it off:: - - # echo 'hist:keys=skbaddr.hex:vals=len' > \ - /sys/kernel/debug/tracing/events/net/netif_rx/trigger - - # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist - - # echo '!hist:keys=skbaddr.hex:vals=len' > \ - /sys/kernel/debug/tracing/events/net/netif_rx/trigger - - The trigger file itself can be read to show the details of the - currently attached hist trigger. This information is also displayed - at the top of the 'hist' file when read. - - By default, the size of the hash table is 2048 entries. The 'size' - parameter can be used to specify more or fewer than that. The units - are in terms of hashtable entries - if a run uses more entries than - specified, the results will show the number of 'drops', the number - of hits that were ignored. The size should be a power of 2 between - 128 and 131072 (any non- power-of-2 number specified will be rounded - up). - - The 'sort' parameter can be used to specify a value field to sort - on. The default if unspecified is 'hitcount' and the default sort - order is 'ascending'. To sort in the opposite direction, append - .descending' to the sort key. - - The 'pause' parameter can be used to pause an existing hist trigger - or to start a hist trigger but not log any events until told to do - so. 'continue' or 'cont' can be used to start or restart a paused - hist trigger. - - The 'clear' parameter will clear the contents of a running hist - trigger and leave its current paused/active state. - - Note that the 'pause', 'cont', and 'clear' parameters should be - applied using 'append' shell operator ('>>') if applied to an - existing trigger, rather than via the '>' operator, which will cause - the trigger to be removed through truncation. - -- enable_hist/disable_hist - - The enable_hist and disable_hist triggers can be used to have one - event conditionally start and stop another event's already-attached - hist trigger. Any number of enable_hist and disable_hist triggers - can be attached to a given event, allowing that event to kick off - and stop aggregations on a host of other events. - - The format is very similar to the enable/disable_event triggers:: - - enable_hist:<system>:<event>[:count] - disable_hist:<system>:<event>[:count] - - Instead of enabling or disabling the tracing of the target event - into the trace buffer as the enable/disable_event triggers do, the - enable/disable_hist triggers enable or disable the aggregation of - the target event into a hash table. - - A typical usage scenario for the enable_hist/disable_hist triggers - would be to first set up a paused hist trigger on some event, - followed by an enable_hist/disable_hist pair that turns the hist - aggregation on and off when conditions of interest are hit:: - - # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - - # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger - - # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger - - The above sets up an initially paused hist trigger which is unpaused - and starts aggregating events when a given program is executed, and - which stops aggregating when the process exits and the hist trigger - is paused again. - - The examples below provide a more concrete illustration of the - concepts and typical usage patterns discussed above. - - -6.2 'hist' trigger examples ---------------------------- - - The first set of examples creates aggregations using the kmalloc - event. The fields that can be used for the hist trigger are listed - in the kmalloc event's format file:: - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format - name: kmalloc - ID: 374 - format: - field:unsigned short common_type; offset:0; size:2; signed:0; - field:unsigned char common_flags; offset:2; size:1; signed:0; - field:unsigned char common_preempt_count; offset:3; size:1; signed:0; - field:int common_pid; offset:4; size:4; signed:1; - - field:unsigned long call_site; offset:8; size:8; signed:0; - field:const void * ptr; offset:16; size:8; signed:0; - field:size_t bytes_req; offset:24; size:8; signed:0; - field:size_t bytes_alloc; offset:32; size:8; signed:0; - field:gfp_t gfp_flags; offset:40; size:4; signed:0; - - We'll start by creating a hist trigger that generates a simple table - that lists the total number of bytes requested for each function in - the kernel that made one or more calls to kmalloc:: - - # echo 'hist:key=call_site:val=bytes_req' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - This tells the tracing system to create a 'hist' trigger using the - call_site field of the kmalloc event as the key for the table, which - just means that each unique call_site address will have an entry - created for it in the table. The 'val=bytes_req' parameter tells - the hist trigger that for each unique entry (call_site) in the - table, it should keep a running total of the number of bytes - requested by that call_site. - - We'll let it run for awhile and then dump the contents of the 'hist' - file in the kmalloc event's subdirectory (for readability, a number - of entries have been omitted):: - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] - - { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176 - { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024 - { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384 - { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24 - { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8 - { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152 - { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144 - { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144 - { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560 - { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736 - . - . - . - { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576 - { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336 - { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504 - { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584 - { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448 - { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720 - { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088 - { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920 - { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716 - { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712 - { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160 - { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520 - - Totals: - Hits: 4610 - Entries: 45 - Dropped: 0 - - The output displays a line for each entry, beginning with the key - specified in the trigger, followed by the value(s) also specified in - the trigger. At the beginning of the output is a line that displays - the trigger info, which can also be displayed by reading the - 'trigger' file:: - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] - - At the end of the output are a few lines that display the overall - totals for the run. The 'Hits' field shows the total number of - times the event trigger was hit, the 'Entries' field shows the total - number of used entries in the hash table, and the 'Dropped' field - shows the number of hits that were dropped because the number of - used entries for the run exceeded the maximum number of entries - allowed for the table (normally 0, but if not a hint that you may - want to increase the size of the table using the 'size' parameter). - - Notice in the above output that there's an extra field, 'hitcount', - which wasn't specified in the trigger. Also notice that in the - trigger info output, there's a parameter, 'sort=hitcount', which - wasn't specified in the trigger either. The reason for that is that - every trigger implicitly keeps a count of the total number of hits - attributed to a given entry, called the 'hitcount'. That hitcount - information is explicitly displayed in the output, and in the - absence of a user-specified sort parameter, is used as the default - sort field. - - The value 'hitcount' can be used in place of an explicit value in - the 'values' parameter if you don't really need to have any - particular field summed and are mainly interested in hit - frequencies. - - To turn the hist trigger off, simply call up the trigger in the - command history and re-execute it with a '!' prepended:: - - # echo '!hist:key=call_site:val=bytes_req' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - Finally, notice that the call_site as displayed in the output above - isn't really very useful. It's an address, but normally addresses - are displayed in hex. To have a numeric field displayed as a hex - value, simply append '.hex' to the field name in the trigger:: - - # echo 'hist:key=call_site.hex:val=bytes_req' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active] - - { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433 - { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176 - { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384 - { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8 - { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511 - { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12 - { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152 - { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24 - { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144 - { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648 - { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144 - { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544 - . - . - . - { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024 - { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680 - { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112 - { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232 - { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360 - { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640 - { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600 - { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584 - { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656 - { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456 - { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600 - - Totals: - Hits: 4775 - Entries: 46 - Dropped: 0 - - Even that's only marginally more useful - while hex values do look - more like addresses, what users are typically more interested in - when looking at text addresses are the corresponding symbols - instead. To have an address displayed as symbolic value instead, - simply append '.sym' or '.sym-offset' to the field name in the - trigger:: - - # echo 'hist:key=call_site.sym:val=bytes_req' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active] - - { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024 - { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 - { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 - { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192 - { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 - { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 - { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 - { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528 - { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624 - { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96 - { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464 - { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304 - { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 - { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424 - . - . - . - { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240 - { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280 - { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672 - { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208 - { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840 - { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312 - { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152 - { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576 - { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248 - { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384 - { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584 - { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176 - { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265 - - Totals: - Hits: 109928 - Entries: 71 - Dropped: 0 - - Because the default sort key above is 'hitcount', the above shows a - the list of call_sites by increasing hitcount, so that at the bottom - we see the functions that made the most kmalloc calls during the - run. If instead we we wanted to see the top kmalloc callers in - terms of the number of bytes requested rather than the number of - calls, and we wanted the top caller to appear at the top, we can use - the 'sort' parameter, along with the 'descending' modifier:: - - # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] - - { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464 - { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176 - { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135 - { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128 - { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784 - { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992 - { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072 - { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824 - { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704 - { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088 - { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536 - { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664 - { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632 - . - . - . - { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 - { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 - { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48 - { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48 - { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48 - { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 - { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16 - { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 - { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 - { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 - - Totals: - Hits: 32133 - Entries: 81 - Dropped: 0 - - To display the offset and size information in addition to the symbol - name, just use 'sym-offset' instead:: - - # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] - - { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720 - { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936 - { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936 - { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832 - { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384 - { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040 - { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072 - { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880 - { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488 - { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696 - { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640 - { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456 - . - . - . - { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128 - { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96 - { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96 - { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84 - { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8 - { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7 - { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7 - - Totals: - Hits: 26098 - Entries: 64 - Dropped: 0 - - We can also add multiple fields to the 'values' parameter. For - example, we might want to see the total number of bytes allocated - alongside bytes requested, and display the result sorted by bytes - allocated in a descending order:: - - # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active] - - { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016 - { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224 - { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568 - { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760 - { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744 - { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400 - { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496 - { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304 - { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640 - { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760 - { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312 - { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432 - . - . - . - { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192 - { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 - { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 - { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 - { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 - { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96 - { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64 - { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 - { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8 - { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 - - Totals: - Hits: 66598 - Entries: 65 - Dropped: 0 - - Finally, to finish off our kmalloc example, instead of simply having - the hist trigger display symbolic call_sites, we can have the hist - trigger additionally display the complete set of kernel stack traces - that led to each call_site. To do that, we simply use the special - value 'stacktrace' for the key parameter:: - - # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \ - /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger - - The above trigger will use the kernel stack trace in effect when an - event is triggered as the key for the hash table. This allows the - enumeration of every kernel callpath that led up to a particular - event, along with a running total of any of the event fields for - that event. Here we tally bytes requested and bytes allocated for - every callpath in the system that led up to a kmalloc (in this case - every callpath to a kmalloc for a kernel compile):: - - # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist - # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active] - - { stacktrace: - __kmalloc_track_caller+0x10b/0x1a0 - kmemdup+0x20/0x50 - hidraw_report_event+0x8a/0x120 [hid] - hid_report_raw_event+0x3ea/0x440 [hid] - hid_input_report+0x112/0x190 [hid] - hid_irq_in+0xc2/0x260 [usbhid] - __usb_hcd_giveback_urb+0x72/0x120 - usb_giveback_urb_bh+0x9e/0xe0 - tasklet_hi_action+0xf8/0x100 - __do_softirq+0x114/0x2c0 - irq_exit+0xa5/0xb0 - do_IRQ+0x5a/0xf0 - ret_from_intr+0x0/0x30 - cpuidle_enter+0x17/0x20 - cpu_startup_entry+0x315/0x3e0 - rest_init+0x7c/0x80 - } hitcount: 3 bytes_req: 21 bytes_alloc: 24 - { stacktrace: - __kmalloc_track_caller+0x10b/0x1a0 - kmemdup+0x20/0x50 - hidraw_report_event+0x8a/0x120 [hid] - hid_report_raw_event+0x3ea/0x440 [hid] - hid_input_report+0x112/0x190 [hid] - hid_irq_in+0xc2/0x260 [usbhid] - __usb_hcd_giveback_urb+0x72/0x120 - usb_giveback_urb_bh+0x9e/0xe0 - tasklet_hi_action+0xf8/0x100 - __do_softirq+0x114/0x2c0 - irq_exit+0xa5/0xb0 - do_IRQ+0x5a/0xf0 - ret_from_intr+0x0/0x30 - } hitcount: 3 bytes_req: 21 bytes_alloc: 24 - { stacktrace: - kmem_cache_alloc_trace+0xeb/0x150 - aa_alloc_task_context+0x27/0x40 - apparmor_cred_prepare+0x1f/0x50 - security_prepare_creds+0x16/0x20 - prepare_creds+0xdf/0x1a0 - SyS_capset+0xb5/0x200 - system_call_fastpath+0x12/0x6a - } hitcount: 1 bytes_req: 32 bytes_alloc: 32 - . - . - . - { stacktrace: - __kmalloc+0x11b/0x1b0 - i915_gem_execbuffer2+0x6c/0x2c0 [i915] - drm_ioctl+0x349/0x670 [drm] - do_vfs_ioctl+0x2f0/0x4f0 - SyS_ioctl+0x81/0xa0 - system_call_fastpath+0x12/0x6a - } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808 - { stacktrace: - __kmalloc+0x11b/0x1b0 - load_elf_phdrs+0x76/0xa0 - load_elf_binary+0x102/0x1650 - search_binary_handler+0x97/0x1d0 - do_execveat_common.isra.34+0x551/0x6e0 - SyS_execve+0x3a/0x50 - return_from_execve+0x0/0x23 - } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048 - { stacktrace: - kmem_cache_alloc_trace+0xeb/0x150 - apparmor_file_alloc_security+0x27/0x40 - security_file_alloc+0x16/0x20 - get_empty_filp+0x93/0x1c0 - path_openat+0x31/0x5f0 - do_filp_open+0x3a/0x90 - do_sys_open+0x128/0x220 - SyS_open+0x1e/0x20 - system_call_fastpath+0x12/0x6a - } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376 - { stacktrace: - __kmalloc+0x11b/0x1b0 - seq_buf_alloc+0x1b/0x50 - seq_read+0x2cc/0x370 - proc_reg_read+0x3d/0x80 - __vfs_read+0x28/0xe0 - vfs_read+0x86/0x140 - SyS_read+0x46/0xb0 - system_call_fastpath+0x12/0x6a - } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768 - - Totals: - Hits: 6085872 - Entries: 253 - Dropped: 0 - - If you key a hist trigger on common_pid, in order for example to - gather and display sorted totals for each process, you can use the - special .execname modifier to display the executable names for the - processes in the table rather than raw pids. The example below - keeps a per-process sum of total bytes read:: - - # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \ - /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger - - # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist - # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active] - - { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512 - { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640 - { common_pid: compiz [ 2889] } hitcount: 59 count: 254400 - { common_pid: bash [ 8710] } hitcount: 3 count: 66369 - { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739 - { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648 - { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216 - { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396 - { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264 - { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424 - { common_pid: gmain [ 1315] } hitcount: 18 count: 6336 - . - . - . - { common_pid: postgres [ 1892] } hitcount: 2 count: 32 - { common_pid: postgres [ 1891] } hitcount: 2 count: 32 - { common_pid: gmain [ 8704] } hitcount: 2 count: 32 - { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21 - { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16 - { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16 - { common_pid: gdbus [ 2998] } hitcount: 1 count: 16 - { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8 - { common_pid: init [ 1] } hitcount: 2 count: 2 - - Totals: - Hits: 2116 - Entries: 51 - Dropped: 0 - - Similarly, if you key a hist trigger on syscall id, for example to - gather and display a list of systemwide syscall hits, you can use - the special .syscall modifier to display the syscall names rather - than raw ids. The example below keeps a running total of syscall - counts for the system during the run:: - - # echo 'hist:key=id.syscall:val=hitcount' > \ - /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger - - # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist - # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active] - - { id: sys_fsync [ 74] } hitcount: 1 - { id: sys_newuname [ 63] } hitcount: 1 - { id: sys_prctl [157] } hitcount: 1 - { id: sys_statfs [137] } hitcount: 1 - { id: sys_symlink [ 88] } hitcount: 1 - { id: sys_sendmmsg [307] } hitcount: 1 - { id: sys_semctl [ 66] } hitcount: 1 - { id: sys_readlink [ 89] } hitcount: 3 - { id: sys_bind [ 49] } hitcount: 3 - { id: sys_getsockname [ 51] } hitcount: 3 - { id: sys_unlink [ 87] } hitcount: 3 - { id: sys_rename [ 82] } hitcount: 4 - { id: unknown_syscall [ 58] } hitcount: 4 - { id: sys_connect [ 42] } hitcount: 4 - { id: sys_getpid [ 39] } hitcount: 4 - . - . - . - { id: sys_rt_sigprocmask [ 14] } hitcount: 952 - { id: sys_futex [202] } hitcount: 1534 - { id: sys_write [ 1] } hitcount: 2689 - { id: sys_setitimer [ 38] } hitcount: 2797 - { id: sys_read [ 0] } hitcount: 3202 - { id: sys_select [ 23] } hitcount: 3773 - { id: sys_writev [ 20] } hitcount: 4531 - { id: sys_poll [ 7] } hitcount: 8314 - { id: sys_recvmsg [ 47] } hitcount: 13738 - { id: sys_ioctl [ 16] } hitcount: 21843 - - Totals: - Hits: 67612 - Entries: 72 - Dropped: 0 - - The syscall counts above provide a rough overall picture of system - call activity on the system; we can see for example that the most - popular system call on this system was the 'sys_ioctl' system call. - - We can use 'compound' keys to refine that number and provide some - further insight as to which processes exactly contribute to the - overall ioctl count. - - The command below keeps a hitcount for every unique combination of - system call id and pid - the end result is essentially a table - that keeps a per-pid sum of system call hits. The results are - sorted using the system call id as the primary key, and the - hitcount sum as the secondary key:: - - # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \ - /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger - - # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist - # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active] - - { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1 - { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1 - { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1 - { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1 - { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2 - { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2 - { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2 - { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2 - { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2 - { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2 - . - . - . - { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12 - { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16 - { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808 - { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580 - . - . - . - { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3 - { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4 - { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6 - { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2 - { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4 - { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6 - - Totals: - Hits: 31536 - Entries: 323 - Dropped: 0 - - The above list does give us a breakdown of the ioctl syscall by - pid, but it also gives us quite a bit more than that, which we - don't really care about at the moment. Since we know the syscall - id for sys_ioctl (16, displayed next to the sys_ioctl name), we - can use that to filter out all the other syscalls:: - - # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \ - /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger - - # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist - # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active] - - { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1 - { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1 - . - . - . - { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45 - { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48 - { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48 - { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66 - { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674 - { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443 - - Totals: - Hits: 101162 - Entries: 103 - Dropped: 0 - - The above output shows that 'compiz' and 'Xorg' are far and away - the heaviest ioctl callers (which might lead to questions about - whether they really need to be making all those calls and to - possible avenues for further investigation.) - - The compound key examples used a key and a sum value (hitcount) to - sort the output, but we can just as easily use two keys instead. - Here's an example where we use a compound key composed of the the - common_pid and size event fields. Sorting with pid as the primary - key and 'size' as the secondary key allows us to display an - ordered summary of the recvfrom sizes, with counts, received by - each process:: - - # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \ - /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger - - # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist - # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active] - - { common_pid: smbd [ 784], size: 4 } hitcount: 1 - { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672 - { common_pid: postgres [ 1796], size: 1000 } hitcount: 6 - { common_pid: postgres [ 1867], size: 1000 } hitcount: 10 - { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2 - { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1 - { common_pid: compiz [ 2994], size: 8 } hitcount: 1 - { common_pid: compiz [ 2994], size: 20 } hitcount: 11 - { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2 - { common_pid: firefox [ 8817], size: 4 } hitcount: 1 - { common_pid: firefox [ 8817], size: 8 } hitcount: 5 - { common_pid: firefox [ 8817], size: 588 } hitcount: 2 - { common_pid: firefox [ 8817], size: 628 } hitcount: 1 - { common_pid: firefox [ 8817], size: 6944 } hitcount: 1 - { common_pid: firefox [ 8817], size: 408880 } hitcount: 2 - { common_pid: firefox [ 8822], size: 8 } hitcount: 2 - { common_pid: firefox [ 8822], size: 160 } hitcount: 2 - { common_pid: firefox [ 8822], size: 320 } hitcount: 2 - { common_pid: firefox [ 8822], size: 352 } hitcount: 1 - . - . - . - { common_pid: pool [ 8923], size: 1960 } hitcount: 10 - { common_pid: pool [ 8923], size: 2048 } hitcount: 10 - { common_pid: pool [ 8924], size: 1960 } hitcount: 10 - { common_pid: pool [ 8924], size: 2048 } hitcount: 10 - { common_pid: pool [ 8928], size: 1964 } hitcount: 4 - { common_pid: pool [ 8928], size: 1965 } hitcount: 2 - { common_pid: pool [ 8928], size: 2048 } hitcount: 6 - { common_pid: pool [ 8929], size: 1982 } hitcount: 1 - { common_pid: pool [ 8929], size: 2048 } hitcount: 1 - - Totals: - Hits: 2016 - Entries: 224 - Dropped: 0 - - The above example also illustrates the fact that although a compound - key is treated as a single entity for hashing purposes, the sub-keys - it's composed of can be accessed independently. - - The next example uses a string field as the hash key and - demonstrates how you can manually pause and continue a hist trigger. - In this example, we'll aggregate fork counts and don't expect a - large number of entries in the hash table, so we'll drop it to a - much smaller number, say 256:: - - # echo 'hist:key=child_comm:val=hitcount:size=256' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist - # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] - - { child_comm: dconf worker } hitcount: 1 - { child_comm: ibus-daemon } hitcount: 1 - { child_comm: whoopsie } hitcount: 1 - { child_comm: smbd } hitcount: 1 - { child_comm: gdbus } hitcount: 1 - { child_comm: kthreadd } hitcount: 1 - { child_comm: dconf worker } hitcount: 1 - { child_comm: evolution-alarm } hitcount: 2 - { child_comm: Socket Thread } hitcount: 2 - { child_comm: postgres } hitcount: 2 - { child_comm: bash } hitcount: 3 - { child_comm: compiz } hitcount: 3 - { child_comm: evolution-sourc } hitcount: 4 - { child_comm: dhclient } hitcount: 4 - { child_comm: pool } hitcount: 5 - { child_comm: nm-dispatcher.a } hitcount: 8 - { child_comm: firefox } hitcount: 8 - { child_comm: dbus-daemon } hitcount: 8 - { child_comm: glib-pacrunner } hitcount: 10 - { child_comm: evolution } hitcount: 23 - - Totals: - Hits: 89 - Entries: 20 - Dropped: 0 - - If we want to pause the hist trigger, we can simply append :pause to - the command that started the trigger. Notice that the trigger info - displays as [paused]:: - - # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \ - /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist - # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused] - - { child_comm: dconf worker } hitcount: 1 - { child_comm: kthreadd } hitcount: 1 - { child_comm: dconf worker } hitcount: 1 - { child_comm: gdbus } hitcount: 1 - { child_comm: ibus-daemon } hitcount: 1 - { child_comm: Socket Thread } hitcount: 2 - { child_comm: evolution-alarm } hitcount: 2 - { child_comm: smbd } hitcount: 2 - { child_comm: bash } hitcount: 3 - { child_comm: whoopsie } hitcount: 3 - { child_comm: compiz } hitcount: 3 - { child_comm: evolution-sourc } hitcount: 4 - { child_comm: pool } hitcount: 5 - { child_comm: postgres } hitcount: 6 - { child_comm: firefox } hitcount: 8 - { child_comm: dhclient } hitcount: 10 - { child_comm: emacs } hitcount: 12 - { child_comm: dbus-daemon } hitcount: 20 - { child_comm: nm-dispatcher.a } hitcount: 20 - { child_comm: evolution } hitcount: 35 - { child_comm: glib-pacrunner } hitcount: 59 - - Totals: - Hits: 199 - Entries: 21 - Dropped: 0 - - To manually continue having the trigger aggregate events, append - :cont instead. Notice that the trigger info displays as [active] - again, and the data has changed:: - - # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \ - /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist - # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] - - { child_comm: dconf worker } hitcount: 1 - { child_comm: dconf worker } hitcount: 1 - { child_comm: kthreadd } hitcount: 1 - { child_comm: gdbus } hitcount: 1 - { child_comm: ibus-daemon } hitcount: 1 - { child_comm: Socket Thread } hitcount: 2 - { child_comm: evolution-alarm } hitcount: 2 - { child_comm: smbd } hitcount: 2 - { child_comm: whoopsie } hitcount: 3 - { child_comm: compiz } hitcount: 3 - { child_comm: evolution-sourc } hitcount: 4 - { child_comm: bash } hitcount: 5 - { child_comm: pool } hitcount: 5 - { child_comm: postgres } hitcount: 6 - { child_comm: firefox } hitcount: 8 - { child_comm: dhclient } hitcount: 11 - { child_comm: emacs } hitcount: 12 - { child_comm: dbus-daemon } hitcount: 22 - { child_comm: nm-dispatcher.a } hitcount: 22 - { child_comm: evolution } hitcount: 35 - { child_comm: glib-pacrunner } hitcount: 59 - - Totals: - Hits: 206 - Entries: 21 - Dropped: 0 - - The previous example showed how to start and stop a hist trigger by - appending 'pause' and 'continue' to the hist trigger command. A - hist trigger can also be started in a paused state by initially - starting the trigger with ':pause' appended. This allows you to - start the trigger only when you're ready to start collecting data - and not before. For example, you could start the trigger in a - paused state, then unpause it and do something you want to measure, - then pause the trigger again when done. - - Of course, doing this manually can be difficult and error-prone, but - it is possible to automatically start and stop a hist trigger based - on some condition, via the enable_hist and disable_hist triggers. - - For example, suppose we wanted to take a look at the relative - weights in terms of skb length for each callpath that leads to a - netif_receieve_skb event when downloading a decent-sized file using - wget. - - First we set up an initially paused stacktrace trigger on the - netif_receive_skb event:: - - # echo 'hist:key=stacktrace:vals=len:pause' > \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - - Next, we set up an 'enable_hist' trigger on the sched_process_exec - event, with an 'if filename==/usr/bin/wget' filter. The effect of - this new trigger is that it will 'unpause' the hist trigger we just - set up on netif_receive_skb if and only if it sees a - sched_process_exec event with a filename of '/usr/bin/wget'. When - that happens, all netif_receive_skb events are aggregated into a - hash table keyed on stacktrace:: - - # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger - - The aggregation continues until the netif_receive_skb is paused - again, which is what the following disable_hist event does by - creating a similar setup on the sched_process_exit event, using the - filter 'comm==wget':: - - # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger - - Whenever a process exits and the comm field of the disable_hist - trigger filter matches 'comm==wget', the netif_receive_skb hist - trigger is disabled. - - The overall effect is that netif_receive_skb events are aggregated - into the hash table for only the duration of the wget. Executing a - wget command and then listing the 'hist' file will display the - output generated by the wget command:: - - $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz - - # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist - # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] - - { stacktrace: - __netif_receive_skb_core+0x46d/0x990 - __netif_receive_skb+0x18/0x60 - netif_receive_skb_internal+0x23/0x90 - napi_gro_receive+0xc8/0x100 - ieee80211_deliver_skb+0xd6/0x270 [mac80211] - ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] - ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] - ieee80211_rx+0x31d/0x900 [mac80211] - iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] - iwl_rx_dispatch+0x8e/0xf0 [iwldvm] - iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] - irq_thread_fn+0x20/0x50 - irq_thread+0x11f/0x150 - kthread+0xd2/0xf0 - ret_from_fork+0x42/0x70 - } hitcount: 85 len: 28884 - { stacktrace: - __netif_receive_skb_core+0x46d/0x990 - __netif_receive_skb+0x18/0x60 - netif_receive_skb_internal+0x23/0x90 - napi_gro_complete+0xa4/0xe0 - dev_gro_receive+0x23a/0x360 - napi_gro_receive+0x30/0x100 - ieee80211_deliver_skb+0xd6/0x270 [mac80211] - ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] - ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] - ieee80211_rx+0x31d/0x900 [mac80211] - iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] - iwl_rx_dispatch+0x8e/0xf0 [iwldvm] - iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] - irq_thread_fn+0x20/0x50 - irq_thread+0x11f/0x150 - kthread+0xd2/0xf0 - } hitcount: 98 len: 664329 - { stacktrace: - __netif_receive_skb_core+0x46d/0x990 - __netif_receive_skb+0x18/0x60 - process_backlog+0xa8/0x150 - net_rx_action+0x15d/0x340 - __do_softirq+0x114/0x2c0 - do_softirq_own_stack+0x1c/0x30 - do_softirq+0x65/0x70 - __local_bh_enable_ip+0xb5/0xc0 - ip_finish_output+0x1f4/0x840 - ip_output+0x6b/0xc0 - ip_local_out_sk+0x31/0x40 - ip_send_skb+0x1a/0x50 - udp_send_skb+0x173/0x2a0 - udp_sendmsg+0x2bf/0x9f0 - inet_sendmsg+0x64/0xa0 - sock_sendmsg+0x3d/0x50 - } hitcount: 115 len: 13030 - { stacktrace: - __netif_receive_skb_core+0x46d/0x990 - __netif_receive_skb+0x18/0x60 - netif_receive_skb_internal+0x23/0x90 - napi_gro_complete+0xa4/0xe0 - napi_gro_flush+0x6d/0x90 - iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi] - irq_thread_fn+0x20/0x50 - irq_thread+0x11f/0x150 - kthread+0xd2/0xf0 - ret_from_fork+0x42/0x70 - } hitcount: 934 len: 5512212 - - Totals: - Hits: 1232 - Entries: 4 - Dropped: 0 - - The above shows all the netif_receive_skb callpaths and their total - lengths for the duration of the wget command. - - The 'clear' hist trigger param can be used to clear the hash table. - Suppose we wanted to try another run of the previous example but - this time also wanted to see the complete list of events that went - into the histogram. In order to avoid having to set everything up - again, we can just clear the histogram first:: - - # echo 'hist:key=stacktrace:vals=len:clear' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - - Just to verify that it is in fact cleared, here's what we now see in - the hist file:: - - # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist - # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] - - Totals: - Hits: 0 - Entries: 0 - Dropped: 0 - - Since we want to see the detailed list of every netif_receive_skb - event occurring during the new run, which are in fact the same - events being aggregated into the hash table, we add some additional - 'enable_event' events to the triggering sched_process_exec and - sched_process_exit events as such:: - - # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger - - # echo 'disable_event:net:netif_receive_skb if comm==wget' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger - - If you read the trigger files for the sched_process_exec and - sched_process_exit triggers, you should see two triggers for each: - one enabling/disabling the hist aggregation and the other - enabling/disabling the logging of events:: - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger - enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget - enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger - enable_event:net:netif_receive_skb:unlimited if comm==wget - disable_hist:net:netif_receive_skb:unlimited if comm==wget - - In other words, whenever either of the sched_process_exec or - sched_process_exit events is hit and matches 'wget', it enables or - disables both the histogram and the event log, and what you end up - with is a hash table and set of events just covering the specified - duration. Run the wget command again:: - - $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz - - Displaying the 'hist' file should show something similar to what you - saw in the last run, but this time you should also see the - individual events in the trace file:: - - # cat /sys/kernel/debug/tracing/trace - - # tracer: nop - # - # entries-in-buffer/entries-written: 183/1426 #P:4 - # - # _-----=> irqs-off - # / _----=> need-resched - # | / _---=> hardirq/softirq - # || / _--=> preempt-depth - # ||| / delay - # TASK-PID CPU# |||| TIMESTAMP FUNCTION - # | | | |||| | | - wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60 - wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60 - dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130 - dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138 - ##### CPU 2 buffer started #### - irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948 - irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500 - irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948 - irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948 - irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500 - .... - - - The following example demonstrates how multiple hist triggers can be - attached to a given event. This capability can be useful for - creating a set of different summaries derived from the same set of - events, or for comparing the effects of different filters, among - other things. - :: - - # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - # echo 'hist:keys=skbaddr.hex:vals=len' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - # echo 'hist:keys=len:vals=common_preempt_count' >> \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - - The above set of commands create four triggers differing only in - their filters, along with a completely different though fairly - nonsensical trigger. Note that in order to append multiple hist - triggers to the same file, you should use the '>>' operator to - append them ('>' will also add the new hist trigger, but will remove - any existing hist triggers beforehand). - - Displaying the contents of the 'hist' file for the event shows the - contents of all five histograms:: - - # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist - - # event histogram - # - # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active] - # - - { len: 176 } hitcount: 1 common_preempt_count: 0 - { len: 223 } hitcount: 1 common_preempt_count: 0 - { len: 4854 } hitcount: 1 common_preempt_count: 0 - { len: 395 } hitcount: 1 common_preempt_count: 0 - { len: 177 } hitcount: 1 common_preempt_count: 0 - { len: 446 } hitcount: 1 common_preempt_count: 0 - { len: 1601 } hitcount: 1 common_preempt_count: 0 - . - . - . - { len: 1280 } hitcount: 66 common_preempt_count: 0 - { len: 116 } hitcount: 81 common_preempt_count: 40 - { len: 708 } hitcount: 112 common_preempt_count: 0 - { len: 46 } hitcount: 221 common_preempt_count: 0 - { len: 1264 } hitcount: 458 common_preempt_count: 0 - - Totals: - Hits: 1428 - Entries: 147 - Dropped: 0 - - - # event histogram - # - # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] - # - - { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130 - { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280 - { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280 - { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115 - { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115 - { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46 - { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118 - { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60 - { skbaddr: ffff880100065900 } hitcount: 1 len: 46 - { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116 - { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280 - { skbaddr: ffff880100064700 } hitcount: 1 len: 365 - { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60 - . - . - . - { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677 - { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052 - { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589 - { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326 - { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678 - { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678 - { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589 - { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307 - { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032 - - Totals: - Hits: 1451 - Entries: 318 - Dropped: 0 - - - # event histogram - # - # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active] - # - - - Totals: - Hits: 0 - Entries: 0 - Dropped: 0 - - - # event histogram - # - # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active] - # - - { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212 - { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212 - { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212 - { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492 - { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212 - { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212 - { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854 - { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636 - { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924 - { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356 - { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420 - { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996 - - Totals: - Hits: 14 - Entries: 12 - Dropped: 0 - - - # event histogram - # - # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active] - # - - - Totals: - Hits: 0 - Entries: 0 - Dropped: 0 - - Named triggers can be used to have triggers share a common set of - histogram data. This capability is mostly useful for combining the - output of events generated by tracepoints contained inside inline - functions, but names can be used in a hist trigger on any event. - For example, these two triggers when hit will update the same 'len' - field in the shared 'foo' histogram data:: - - # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ - /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger - # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ - /sys/kernel/debug/tracing/events/net/netif_rx/trigger - - You can see that they're updating common histogram data by reading - each event's hist files at the same time:: - - # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist; - cat /sys/kernel/debug/tracing/events/net/netif_rx/hist - - # event histogram - # - # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] - # - - { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 - { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 - { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 - { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 - { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 - { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 - { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 - { skbaddr: ffff880064505000 } hitcount: 1 len: 46 - { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 - { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 - { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 - { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 - { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 - { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 - { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 - { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 - { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 - { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 - { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 - { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 - { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 - { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 - { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 - { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 - { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 - { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 - { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 - { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 - { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 - { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 - { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 - { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 - { skbaddr: ffff880064504400 } hitcount: 4 len: 184 - { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 - { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 - { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 - { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 - { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 - - Totals: - Hits: 81 - Entries: 42 - Dropped: 0 - # event histogram - # - # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] - # - - { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 - { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 - { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 - { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 - { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 - { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 - { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 - { skbaddr: ffff880064505000 } hitcount: 1 len: 46 - { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 - { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 - { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 - { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 - { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 - { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 - { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 - { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 - { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 - { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 - { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 - { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 - { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 - { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 - { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 - { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 - { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 - { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 - { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 - { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 - { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 - { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 - { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 - { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 - { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 - { skbaddr: ffff880064504400 } hitcount: 4 len: 184 - { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 - { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 - { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 - { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 - { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 - - Totals: - Hits: 81 - Entries: 42 - Dropped: 0 - - And here's an example that shows how to combine histogram data from - any two events even if they don't share any 'compatible' fields - other than 'hitcount' and 'stacktrace'. These commands create a - couple of triggers named 'bar' using those fields:: - - # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ - /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger - # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ - /sys/kernel/debug/tracing/events/net/netif_rx/trigger - - And displaying the output of either shows some interesting if - somewhat confusing output:: - - # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist - # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist - - # event histogram - # - # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active] - # - - { stacktrace: - _do_fork+0x18e/0x330 - kernel_thread+0x29/0x30 - kthreadd+0x154/0x1b0 - ret_from_fork+0x3f/0x70 - } hitcount: 1 - { stacktrace: - netif_rx_internal+0xb2/0xd0 - netif_rx_ni+0x20/0x70 - dev_loopback_xmit+0xaa/0xd0 - ip_mc_output+0x126/0x240 - ip_local_out_sk+0x31/0x40 - igmp_send_report+0x1e9/0x230 - igmp_timer_expire+0xe9/0x120 - call_timer_fn+0x39/0xf0 - run_timer_softirq+0x1e1/0x290 - __do_softirq+0xfd/0x290 - irq_exit+0x98/0xb0 - smp_apic_timer_interrupt+0x4a/0x60 - apic_timer_interrupt+0x6d/0x80 - cpuidle_enter+0x17/0x20 - call_cpuidle+0x3b/0x60 - cpu_startup_entry+0x22d/0x310 - } hitcount: 1 - { stacktrace: - netif_rx_internal+0xb2/0xd0 - netif_rx_ni+0x20/0x70 - dev_loopback_xmit+0xaa/0xd0 - ip_mc_output+0x17f/0x240 - ip_local_out_sk+0x31/0x40 - ip_send_skb+0x1a/0x50 - udp_send_skb+0x13e/0x270 - udp_sendmsg+0x2bf/0x980 - inet_sendmsg+0x67/0xa0 - sock_sendmsg+0x38/0x50 - SYSC_sendto+0xef/0x170 - SyS_sendto+0xe/0x10 - entry_SYSCALL_64_fastpath+0x12/0x6a - } hitcount: 2 - { stacktrace: - netif_rx_internal+0xb2/0xd0 - netif_rx+0x1c/0x60 - loopback_xmit+0x6c/0xb0 - dev_hard_start_xmit+0x219/0x3a0 - __dev_queue_xmit+0x415/0x4f0 - dev_queue_xmit_sk+0x13/0x20 - ip_finish_output2+0x237/0x340 - ip_finish_output+0x113/0x1d0 - ip_output+0x66/0xc0 - ip_local_out_sk+0x31/0x40 - ip_send_skb+0x1a/0x50 - udp_send_skb+0x16d/0x270 - udp_sendmsg+0x2bf/0x980 - inet_sendmsg+0x67/0xa0 - sock_sendmsg+0x38/0x50 - ___sys_sendmsg+0x14e/0x270 - } hitcount: 76 - { stacktrace: - netif_rx_internal+0xb2/0xd0 - netif_rx+0x1c/0x60 - loopback_xmit+0x6c/0xb0 - dev_hard_start_xmit+0x219/0x3a0 - __dev_queue_xmit+0x415/0x4f0 - dev_queue_xmit_sk+0x13/0x20 - ip_finish_output2+0x237/0x340 - ip_finish_output+0x113/0x1d0 - ip_output+0x66/0xc0 - ip_local_out_sk+0x31/0x40 - ip_send_skb+0x1a/0x50 - udp_send_skb+0x16d/0x270 - udp_sendmsg+0x2bf/0x980 - inet_sendmsg+0x67/0xa0 - sock_sendmsg+0x38/0x50 - ___sys_sendmsg+0x269/0x270 - } hitcount: 77 - { stacktrace: - netif_rx_internal+0xb2/0xd0 - netif_rx+0x1c/0x60 - loopback_xmit+0x6c/0xb0 - dev_hard_start_xmit+0x219/0x3a0 - __dev_queue_xmit+0x415/0x4f0 - dev_queue_xmit_sk+0x13/0x20 - ip_finish_output2+0x237/0x340 - ip_finish_output+0x113/0x1d0 - ip_output+0x66/0xc0 - ip_local_out_sk+0x31/0x40 - ip_send_skb+0x1a/0x50 - udp_send_skb+0x16d/0x270 - udp_sendmsg+0x2bf/0x980 - inet_sendmsg+0x67/0xa0 - sock_sendmsg+0x38/0x50 - SYSC_sendto+0xef/0x170 - } hitcount: 88 - { stacktrace: - _do_fork+0x18e/0x330 - SyS_clone+0x19/0x20 - entry_SYSCALL_64_fastpath+0x12/0x6a - } hitcount: 244 - - Totals: - Hits: 489 - Entries: 7 - Dropped: 0 + See Documentation/trace/histogram.txt for details and examples. diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index fdf5fb54a04c..e45f0786f3f9 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -543,6 +543,30 @@ of ftrace. Here is a list of some of the key files: See events.txt for more information. + timestamp_mode: + + Certain tracers may change the timestamp mode used when + logging trace events into the event buffer. Events with + different modes can coexist within a buffer but the mode in + effect when an event is logged determines which timestamp mode + is used for that event. The default timestamp mode is + 'delta'. + + Usual timestamp modes for tracing: + + # cat timestamp_mode + [delta] absolute + + The timestamp mode with the square brackets around it is the + one in effect. + + delta: Default timestamp mode - timestamp is a delta against + a per-buffer timestamp. + + absolute: The timestamp is a full timestamp, not a delta + against some other value. As such it takes up more + space and is less efficient. + hwlat_detector: Directory for the Hardware Latency Detector. diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt new file mode 100644 index 000000000000..6e05510afc28 --- /dev/null +++ b/Documentation/trace/histogram.txt @@ -0,0 +1,1995 @@ + Event Histograms + + Documentation written by Tom Zanussi + +1. Introduction +=============== + + Histogram triggers are special event triggers that can be used to + aggregate trace event data into histograms. For information on + trace events and event triggers, see Documentation/trace/events.txt. + + +2. Histogram Trigger Command +============================ + + A histogram trigger command is an event trigger command that + aggregates event hits into a hash table keyed on one or more trace + event format fields (or stacktrace) and a set of running totals + derived from one or more trace event format fields and/or event + counts (hitcount). + + The format of a hist trigger is as follows: + + hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>] + [:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue] + [:clear][:name=histname1] [if <filter>] + + When a matching event is hit, an entry is added to a hash table + using the key(s) and value(s) named. Keys and values correspond to + fields in the event's format description. Values must correspond to + numeric fields - on an event hit, the value(s) will be added to a + sum kept for that field. The special string 'hitcount' can be used + in place of an explicit value field - this is simply a count of + event hits. If 'values' isn't specified, an implicit 'hitcount' + value will be automatically created and used as the only value. + Keys can be any field, or the special string 'stacktrace', which + will use the event's kernel stacktrace as the key. The keywords + 'keys' or 'key' can be used to specify keys, and the keywords + 'values', 'vals', or 'val' can be used to specify values. Compound + keys consisting of up to two fields can be specified by the 'keys' + keyword. Hashing a compound key produces a unique entry in the + table for each unique combination of component keys, and can be + useful for providing more fine-grained summaries of event data. + Additionally, sort keys consisting of up to two fields can be + specified by the 'sort' keyword. If more than one field is + specified, the result will be a 'sort within a sort': the first key + is taken to be the primary sort key and the second the secondary + key. If a hist trigger is given a name using the 'name' parameter, + its histogram data will be shared with other triggers of the same + name, and trigger hits will update this common data. Only triggers + with 'compatible' fields can be combined in this way; triggers are + 'compatible' if the fields named in the trigger share the same + number and type of fields and those fields also have the same names. + Note that any two events always share the compatible 'hitcount' and + 'stacktrace' fields and can therefore be combined using those + fields, however pointless that may be. + + 'hist' triggers add a 'hist' file to each event's subdirectory. + Reading the 'hist' file for the event will dump the hash table in + its entirety to stdout. If there are multiple hist triggers + attached to an event, there will be a table for each trigger in the + output. The table displayed for a named trigger will be the same as + any other instance having the same name. Each printed hash table + entry is a simple list of the keys and values comprising the entry; + keys are printed first and are delineated by curly braces, and are + followed by the set of value fields for the entry. By default, + numeric fields are displayed as base-10 integers. This can be + modified by appending any of the following modifiers to the field + name: + + .hex display a number as a hex value + .sym display an address as a symbol + .sym-offset display an address as a symbol and offset + .syscall display a syscall id as a system call name + .execname display a common_pid as a program name + .log2 display log2 value rather than raw number + .usecs display a common_timestamp in microseconds + + Note that in general the semantics of a given field aren't + interpreted when applying a modifier to it, but there are some + restrictions to be aware of in this regard: + + - only the 'hex' modifier can be used for values (because values + are essentially sums, and the other modifiers don't make sense + in that context). + - the 'execname' modifier can only be used on a 'common_pid'. The + reason for this is that the execname is simply the 'comm' value + saved for the 'current' process when an event was triggered, + which is the same as the common_pid value saved by the event + tracing code. Trying to apply that comm value to other pid + values wouldn't be correct, and typically events that care save + pid-specific comm fields in the event itself. + + A typical usage scenario would be the following to enable a hist + trigger, read its current contents, and then turn it off: + + # echo 'hist:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # echo '!hist:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + The trigger file itself can be read to show the details of the + currently attached hist trigger. This information is also displayed + at the top of the 'hist' file when read. + + By default, the size of the hash table is 2048 entries. The 'size' + parameter can be used to specify more or fewer than that. The units + are in terms of hashtable entries - if a run uses more entries than + specified, the results will show the number of 'drops', the number + of hits that were ignored. The size should be a power of 2 between + 128 and 131072 (any non- power-of-2 number specified will be rounded + up). + + The 'sort' parameter can be used to specify a value field to sort + on. The default if unspecified is 'hitcount' and the default sort + order is 'ascending'. To sort in the opposite direction, append + .descending' to the sort key. + + The 'pause' parameter can be used to pause an existing hist trigger + or to start a hist trigger but not log any events until told to do + so. 'continue' or 'cont' can be used to start or restart a paused + hist trigger. + + The 'clear' parameter will clear the contents of a running hist + trigger and leave its current paused/active state. + + Note that the 'pause', 'cont', and 'clear' parameters should be + applied using 'append' shell operator ('>>') if applied to an + existing trigger, rather than via the '>' operator, which will cause + the trigger to be removed through truncation. + +- enable_hist/disable_hist + + The enable_hist and disable_hist triggers can be used to have one + event conditionally start and stop another event's already-attached + hist trigger. Any number of enable_hist and disable_hist triggers + can be attached to a given event, allowing that event to kick off + and stop aggregations on a host of other events. + + The format is very similar to the enable/disable_event triggers: + + enable_hist:<system>:<event>[:count] + disable_hist:<system>:<event>[:count] + + Instead of enabling or disabling the tracing of the target event + into the trace buffer as the enable/disable_event triggers do, the + enable/disable_hist triggers enable or disable the aggregation of + the target event into a hash table. + + A typical usage scenario for the enable_hist/disable_hist triggers + would be to first set up a paused hist trigger on some event, + followed by an enable_hist/disable_hist pair that turns the hist + aggregation on and off when conditions of interest are hit: + + # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + The above sets up an initially paused hist trigger which is unpaused + and starts aggregating events when a given program is executed, and + which stops aggregating when the process exits and the hist trigger + is paused again. + + The examples below provide a more concrete illustration of the + concepts and typical usage patterns discussed above. + + 'special' event fields + ------------------------ + + There are a number of 'special event fields' available for use as + keys or values in a hist trigger. These look like and behave as if + they were actual event fields, but aren't really part of the event's + field definition or format file. They are however available for any + event, and can be used anywhere an actual event field could be. + They are: + + common_timestamp u64 - timestamp (from ring buffer) associated + with the event, in nanoseconds. May be + modified by .usecs to have timestamps + interpreted as microseconds. + cpu int - the cpu on which the event occurred. + + Extended error information + -------------------------- + + For some error conditions encountered when invoking a hist trigger + command, extended error information is available via the + corresponding event's 'hist' file. Reading the hist file after an + error will display more detailed information about what went wrong, + if information is available. This extended error information will + be available until the next hist trigger command for that event. + + If available for a given error condition, the extended error + information and usage takes the following form: + + # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger + echo: write error: Invalid argument + + # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist + ERROR: Couldn't yyy: zzz + Last command: xxx + +6.2 'hist' trigger examples +--------------------------- + + The first set of examples creates aggregations using the kmalloc + event. The fields that can be used for the hist trigger are listed + in the kmalloc event's format file: + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format + name: kmalloc + ID: 374 + format: + field:unsigned short common_type; offset:0; size:2; signed:0; + field:unsigned char common_flags; offset:2; size:1; signed:0; + field:unsigned char common_preempt_count; offset:3; size:1; signed:0; + field:int common_pid; offset:4; size:4; signed:1; + + field:unsigned long call_site; offset:8; size:8; signed:0; + field:const void * ptr; offset:16; size:8; signed:0; + field:size_t bytes_req; offset:24; size:8; signed:0; + field:size_t bytes_alloc; offset:32; size:8; signed:0; + field:gfp_t gfp_flags; offset:40; size:4; signed:0; + + We'll start by creating a hist trigger that generates a simple table + that lists the total number of bytes requested for each function in + the kernel that made one or more calls to kmalloc: + + # echo 'hist:key=call_site:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + This tells the tracing system to create a 'hist' trigger using the + call_site field of the kmalloc event as the key for the table, which + just means that each unique call_site address will have an entry + created for it in the table. The 'val=bytes_req' parameter tells + the hist trigger that for each unique entry (call_site) in the + table, it should keep a running total of the number of bytes + requested by that call_site. + + We'll let it run for awhile and then dump the contents of the 'hist' + file in the kmalloc event's subdirectory (for readability, a number + of entries have been omitted): + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176 + { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024 + { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384 + { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24 + { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8 + { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152 + { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144 + { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144 + { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560 + { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736 + . + . + . + { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576 + { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336 + { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504 + { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584 + { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448 + { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720 + { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088 + { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920 + { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716 + { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712 + { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160 + { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520 + + Totals: + Hits: 4610 + Entries: 45 + Dropped: 0 + + The output displays a line for each entry, beginning with the key + specified in the trigger, followed by the value(s) also specified in + the trigger. At the beginning of the output is a line that displays + the trigger info, which can also be displayed by reading the + 'trigger' file: + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] + + At the end of the output are a few lines that display the overall + totals for the run. The 'Hits' field shows the total number of + times the event trigger was hit, the 'Entries' field shows the total + number of used entries in the hash table, and the 'Dropped' field + shows the number of hits that were dropped because the number of + used entries for the run exceeded the maximum number of entries + allowed for the table (normally 0, but if not a hint that you may + want to increase the size of the table using the 'size' parameter). + + Notice in the above output that there's an extra field, 'hitcount', + which wasn't specified in the trigger. Also notice that in the + trigger info output, there's a parameter, 'sort=hitcount', which + wasn't specified in the trigger either. The reason for that is that + every trigger implicitly keeps a count of the total number of hits + attributed to a given entry, called the 'hitcount'. That hitcount + information is explicitly displayed in the output, and in the + absence of a user-specified sort parameter, is used as the default + sort field. + + The value 'hitcount' can be used in place of an explicit value in + the 'values' parameter if you don't really need to have any + particular field summed and are mainly interested in hit + frequencies. + + To turn the hist trigger off, simply call up the trigger in the + command history and re-execute it with a '!' prepended: + + # echo '!hist:key=call_site:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + Finally, notice that the call_site as displayed in the output above + isn't really very useful. It's an address, but normally addresses + are displayed in hex. To have a numeric field displayed as a hex + value, simply append '.hex' to the field name in the trigger: + + # echo 'hist:key=call_site.hex:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433 + { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176 + { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384 + { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8 + { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511 + { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12 + { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152 + { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24 + { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144 + { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648 + { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144 + { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544 + . + . + . + { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024 + { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680 + { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112 + { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232 + { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360 + { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640 + { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600 + { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584 + { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656 + { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456 + { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600 + + Totals: + Hits: 4775 + Entries: 46 + Dropped: 0 + + Even that's only marginally more useful - while hex values do look + more like addresses, what users are typically more interested in + when looking at text addresses are the corresponding symbols + instead. To have an address displayed as symbolic value instead, + simply append '.sym' or '.sym-offset' to the field name in the + trigger: + + # echo 'hist:key=call_site.sym:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 + { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528 + { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624 + { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96 + { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464 + { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424 + . + . + . + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672 + { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208 + { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576 + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248 + { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584 + { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265 + + Totals: + Hits: 109928 + Entries: 71 + Dropped: 0 + + Because the default sort key above is 'hitcount', the above shows a + the list of call_sites by increasing hitcount, so that at the bottom + we see the functions that made the most kmalloc calls during the + run. If instead we we wanted to see the top kmalloc callers in + terms of the number of bytes requested rather than the number of + calls, and we wanted the top caller to appear at the top, we can use + the 'sort' parameter, along with the 'descending' modifier: + + # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135 + { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784 + { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992 + { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664 + { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632 + . + . + . + { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48 + { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48 + { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48 + { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 + { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 + + Totals: + Hits: 32133 + Entries: 81 + Dropped: 0 + + To display the offset and size information in addition to the symbol + name, just use 'sym-offset' instead: + + # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720 + { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936 + { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832 + { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040 + { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696 + { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640 + { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456 + . + . + . + { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128 + { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96 + { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96 + { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84 + { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7 + + Totals: + Hits: 26098 + Entries: 64 + Dropped: 0 + + We can also add multiple fields to the 'values' parameter. For + example, we might want to see the total number of bytes allocated + alongside bytes requested, and display the result sorted by bytes + allocated in a descending order: + + # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016 + { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744 + { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304 + { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640 + { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432 + . + . + . + { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192 + { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96 + { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 + + Totals: + Hits: 66598 + Entries: 65 + Dropped: 0 + + Finally, to finish off our kmalloc example, instead of simply having + the hist trigger display symbolic call_sites, we can have the hist + trigger additionally display the complete set of kernel stack traces + that led to each call_site. To do that, we simply use the special + value 'stacktrace' for the key parameter: + + # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + The above trigger will use the kernel stack trace in effect when an + event is triggered as the key for the hash table. This allows the + enumeration of every kernel callpath that led up to a particular + event, along with a running total of any of the event fields for + that event. Here we tally bytes requested and bytes allocated for + every callpath in the system that led up to a kmalloc (in this case + every callpath to a kmalloc for a kernel compile): + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active] + + { stacktrace: + __kmalloc_track_caller+0x10b/0x1a0 + kmemdup+0x20/0x50 + hidraw_report_event+0x8a/0x120 [hid] + hid_report_raw_event+0x3ea/0x440 [hid] + hid_input_report+0x112/0x190 [hid] + hid_irq_in+0xc2/0x260 [usbhid] + __usb_hcd_giveback_urb+0x72/0x120 + usb_giveback_urb_bh+0x9e/0xe0 + tasklet_hi_action+0xf8/0x100 + __do_softirq+0x114/0x2c0 + irq_exit+0xa5/0xb0 + do_IRQ+0x5a/0xf0 + ret_from_intr+0x0/0x30 + cpuidle_enter+0x17/0x20 + cpu_startup_entry+0x315/0x3e0 + rest_init+0x7c/0x80 + } hitcount: 3 bytes_req: 21 bytes_alloc: 24 + { stacktrace: + __kmalloc_track_caller+0x10b/0x1a0 + kmemdup+0x20/0x50 + hidraw_report_event+0x8a/0x120 [hid] + hid_report_raw_event+0x3ea/0x440 [hid] + hid_input_report+0x112/0x190 [hid] + hid_irq_in+0xc2/0x260 [usbhid] + __usb_hcd_giveback_urb+0x72/0x120 + usb_giveback_urb_bh+0x9e/0xe0 + tasklet_hi_action+0xf8/0x100 + __do_softirq+0x114/0x2c0 + irq_exit+0xa5/0xb0 + do_IRQ+0x5a/0xf0 + ret_from_intr+0x0/0x30 + } hitcount: 3 bytes_req: 21 bytes_alloc: 24 + { stacktrace: + kmem_cache_alloc_trace+0xeb/0x150 + aa_alloc_task_context+0x27/0x40 + apparmor_cred_prepare+0x1f/0x50 + security_prepare_creds+0x16/0x20 + prepare_creds+0xdf/0x1a0 + SyS_capset+0xb5/0x200 + system_call_fastpath+0x12/0x6a + } hitcount: 1 bytes_req: 32 bytes_alloc: 32 + . + . + . + { stacktrace: + __kmalloc+0x11b/0x1b0 + i915_gem_execbuffer2+0x6c/0x2c0 [i915] + drm_ioctl+0x349/0x670 [drm] + do_vfs_ioctl+0x2f0/0x4f0 + SyS_ioctl+0x81/0xa0 + system_call_fastpath+0x12/0x6a + } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808 + { stacktrace: + __kmalloc+0x11b/0x1b0 + load_elf_phdrs+0x76/0xa0 + load_elf_binary+0x102/0x1650 + search_binary_handler+0x97/0x1d0 + do_execveat_common.isra.34+0x551/0x6e0 + SyS_execve+0x3a/0x50 + return_from_execve+0x0/0x23 + } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048 + { stacktrace: + kmem_cache_alloc_trace+0xeb/0x150 + apparmor_file_alloc_security+0x27/0x40 + security_file_alloc+0x16/0x20 + get_empty_filp+0x93/0x1c0 + path_openat+0x31/0x5f0 + do_filp_open+0x3a/0x90 + do_sys_open+0x128/0x220 + SyS_open+0x1e/0x20 + system_call_fastpath+0x12/0x6a + } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376 + { stacktrace: + __kmalloc+0x11b/0x1b0 + seq_buf_alloc+0x1b/0x50 + seq_read+0x2cc/0x370 + proc_reg_read+0x3d/0x80 + __vfs_read+0x28/0xe0 + vfs_read+0x86/0x140 + SyS_read+0x46/0xb0 + system_call_fastpath+0x12/0x6a + } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768 + + Totals: + Hits: 6085872 + Entries: 253 + Dropped: 0 + + If you key a hist trigger on common_pid, in order for example to + gather and display sorted totals for each process, you can use the + special .execname modifier to display the executable names for the + processes in the table rather than raw pids. The example below + keeps a per-process sum of total bytes read: + + # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \ + /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger + + # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist + # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active] + + { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512 + { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640 + { common_pid: compiz [ 2889] } hitcount: 59 count: 254400 + { common_pid: bash [ 8710] } hitcount: 3 count: 66369 + { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739 + { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648 + { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216 + { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396 + { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264 + { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424 + { common_pid: gmain [ 1315] } hitcount: 18 count: 6336 + . + . + . + { common_pid: postgres [ 1892] } hitcount: 2 count: 32 + { common_pid: postgres [ 1891] } hitcount: 2 count: 32 + { common_pid: gmain [ 8704] } hitcount: 2 count: 32 + { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21 + { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16 + { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16 + { common_pid: gdbus [ 2998] } hitcount: 1 count: 16 + { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8 + { common_pid: init [ 1] } hitcount: 2 count: 2 + + Totals: + Hits: 2116 + Entries: 51 + Dropped: 0 + + Similarly, if you key a hist trigger on syscall id, for example to + gather and display a list of systemwide syscall hits, you can use + the special .syscall modifier to display the syscall names rather + than raw ids. The example below keeps a running total of syscall + counts for the system during the run: + + # echo 'hist:key=id.syscall:val=hitcount' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active] + + { id: sys_fsync [ 74] } hitcount: 1 + { id: sys_newuname [ 63] } hitcount: 1 + { id: sys_prctl [157] } hitcount: 1 + { id: sys_statfs [137] } hitcount: 1 + { id: sys_symlink [ 88] } hitcount: 1 + { id: sys_sendmmsg [307] } hitcount: 1 + { id: sys_semctl [ 66] } hitcount: 1 + { id: sys_readlink [ 89] } hitcount: 3 + { id: sys_bind [ 49] } hitcount: 3 + { id: sys_getsockname [ 51] } hitcount: 3 + { id: sys_unlink [ 87] } hitcount: 3 + { id: sys_rename [ 82] } hitcount: 4 + { id: unknown_syscall [ 58] } hitcount: 4 + { id: sys_connect [ 42] } hitcount: 4 + { id: sys_getpid [ 39] } hitcount: 4 + . + . + . + { id: sys_rt_sigprocmask [ 14] } hitcount: 952 + { id: sys_futex [202] } hitcount: 1534 + { id: sys_write [ 1] } hitcount: 2689 + { id: sys_setitimer [ 38] } hitcount: 2797 + { id: sys_read [ 0] } hitcount: 3202 + { id: sys_select [ 23] } hitcount: 3773 + { id: sys_writev [ 20] } hitcount: 4531 + { id: sys_poll [ 7] } hitcount: 8314 + { id: sys_recvmsg [ 47] } hitcount: 13738 + { id: sys_ioctl [ 16] } hitcount: 21843 + + Totals: + Hits: 67612 + Entries: 72 + Dropped: 0 + + The syscall counts above provide a rough overall picture of system + call activity on the system; we can see for example that the most + popular system call on this system was the 'sys_ioctl' system call. + + We can use 'compound' keys to refine that number and provide some + further insight as to which processes exactly contribute to the + overall ioctl count. + + The command below keeps a hitcount for every unique combination of + system call id and pid - the end result is essentially a table + that keeps a per-pid sum of system call hits. The results are + sorted using the system call id as the primary key, and the + hitcount sum as the secondary key: + + # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active] + + { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1 + { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1 + { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1 + { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1 + { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2 + { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2 + { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2 + { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2 + { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2 + { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2 + . + . + . + { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12 + { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16 + { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808 + { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580 + . + . + . + { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3 + { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6 + { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2 + { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4 + { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6 + + Totals: + Hits: 31536 + Entries: 323 + Dropped: 0 + + The above list does give us a breakdown of the ioctl syscall by + pid, but it also gives us quite a bit more than that, which we + don't really care about at the moment. Since we know the syscall + id for sys_ioctl (16, displayed next to the sys_ioctl name), we + can use that to filter out all the other syscalls: + + # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active] + + { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1 + . + . + . + { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45 + { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48 + { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48 + { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66 + { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674 + { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443 + + Totals: + Hits: 101162 + Entries: 103 + Dropped: 0 + + The above output shows that 'compiz' and 'Xorg' are far and away + the heaviest ioctl callers (which might lead to questions about + whether they really need to be making all those calls and to + possible avenues for further investigation.) + + The compound key examples used a key and a sum value (hitcount) to + sort the output, but we can just as easily use two keys instead. + Here's an example where we use a compound key composed of the the + common_pid and size event fields. Sorting with pid as the primary + key and 'size' as the secondary key allows us to display an + ordered summary of the recvfrom sizes, with counts, received by + each process: + + # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \ + /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger + + # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist + # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active] + + { common_pid: smbd [ 784], size: 4 } hitcount: 1 + { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672 + { common_pid: postgres [ 1796], size: 1000 } hitcount: 6 + { common_pid: postgres [ 1867], size: 1000 } hitcount: 10 + { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2 + { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1 + { common_pid: compiz [ 2994], size: 8 } hitcount: 1 + { common_pid: compiz [ 2994], size: 20 } hitcount: 11 + { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2 + { common_pid: firefox [ 8817], size: 4 } hitcount: 1 + { common_pid: firefox [ 8817], size: 8 } hitcount: 5 + { common_pid: firefox [ 8817], size: 588 } hitcount: 2 + { common_pid: firefox [ 8817], size: 628 } hitcount: 1 + { common_pid: firefox [ 8817], size: 6944 } hitcount: 1 + { common_pid: firefox [ 8817], size: 408880 } hitcount: 2 + { common_pid: firefox [ 8822], size: 8 } hitcount: 2 + { common_pid: firefox [ 8822], size: 160 } hitcount: 2 + { common_pid: firefox [ 8822], size: 320 } hitcount: 2 + { common_pid: firefox [ 8822], size: 352 } hitcount: 1 + . + . + . + { common_pid: pool [ 8923], size: 1960 } hitcount: 10 + { common_pid: pool [ 8923], size: 2048 } hitcount: 10 + { common_pid: pool [ 8924], size: 1960 } hitcount: 10 + { common_pid: pool [ 8924], size: 2048 } hitcount: 10 + { common_pid: pool [ 8928], size: 1964 } hitcount: 4 + { common_pid: pool [ 8928], size: 1965 } hitcount: 2 + { common_pid: pool [ 8928], size: 2048 } hitcount: 6 + { common_pid: pool [ 8929], size: 1982 } hitcount: 1 + { common_pid: pool [ 8929], size: 2048 } hitcount: 1 + + Totals: + Hits: 2016 + Entries: 224 + Dropped: 0 + + The above example also illustrates the fact that although a compound + key is treated as a single entity for hashing purposes, the sub-keys + it's composed of can be accessed independently. + + The next example uses a string field as the hash key and + demonstrates how you can manually pause and continue a hist trigger. + In this example, we'll aggregate fork counts and don't expect a + large number of entries in the hash table, so we'll drop it to a + much smaller number, say 256: + + # echo 'hist:key=child_comm:val=hitcount:size=256' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: whoopsie } hitcount: 1 + { child_comm: smbd } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: postgres } hitcount: 2 + { child_comm: bash } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: dhclient } hitcount: 4 + { child_comm: pool } hitcount: 5 + { child_comm: nm-dispatcher.a } hitcount: 8 + { child_comm: firefox } hitcount: 8 + { child_comm: dbus-daemon } hitcount: 8 + { child_comm: glib-pacrunner } hitcount: 10 + { child_comm: evolution } hitcount: 23 + + Totals: + Hits: 89 + Entries: 20 + Dropped: 0 + + If we want to pause the hist trigger, we can simply append :pause to + the command that started the trigger. Notice that the trigger info + displays as [paused]: + + # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: smbd } hitcount: 2 + { child_comm: bash } hitcount: 3 + { child_comm: whoopsie } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: pool } hitcount: 5 + { child_comm: postgres } hitcount: 6 + { child_comm: firefox } hitcount: 8 + { child_comm: dhclient } hitcount: 10 + { child_comm: emacs } hitcount: 12 + { child_comm: dbus-daemon } hitcount: 20 + { child_comm: nm-dispatcher.a } hitcount: 20 + { child_comm: evolution } hitcount: 35 + { child_comm: glib-pacrunner } hitcount: 59 + + Totals: + Hits: 199 + Entries: 21 + Dropped: 0 + + To manually continue having the trigger aggregate events, append + :cont instead. Notice that the trigger info displays as [active] + again, and the data has changed: + + # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: smbd } hitcount: 2 + { child_comm: whoopsie } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: bash } hitcount: 5 + { child_comm: pool } hitcount: 5 + { child_comm: postgres } hitcount: 6 + { child_comm: firefox } hitcount: 8 + { child_comm: dhclient } hitcount: 11 + { child_comm: emacs } hitcount: 12 + { child_comm: dbus-daemon } hitcount: 22 + { child_comm: nm-dispatcher.a } hitcount: 22 + { child_comm: evolution } hitcount: 35 + { child_comm: glib-pacrunner } hitcount: 59 + + Totals: + Hits: 206 + Entries: 21 + Dropped: 0 + + The previous example showed how to start and stop a hist trigger by + appending 'pause' and 'continue' to the hist trigger command. A + hist trigger can also be started in a paused state by initially + starting the trigger with ':pause' appended. This allows you to + start the trigger only when you're ready to start collecting data + and not before. For example, you could start the trigger in a + paused state, then unpause it and do something you want to measure, + then pause the trigger again when done. + + Of course, doing this manually can be difficult and error-prone, but + it is possible to automatically start and stop a hist trigger based + on some condition, via the enable_hist and disable_hist triggers. + + For example, suppose we wanted to take a look at the relative + weights in terms of skb length for each callpath that leads to a + netif_receieve_skb event when downloading a decent-sized file using + wget. + + First we set up an initially paused stacktrace trigger on the + netif_receive_skb event: + + # echo 'hist:key=stacktrace:vals=len:pause' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + Next, we set up an 'enable_hist' trigger on the sched_process_exec + event, with an 'if filename==/usr/bin/wget' filter. The effect of + this new trigger is that it will 'unpause' the hist trigger we just + set up on netif_receive_skb if and only if it sees a + sched_process_exec event with a filename of '/usr/bin/wget'. When + that happens, all netif_receive_skb events are aggregated into a + hash table keyed on stacktrace: + + # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + The aggregation continues until the netif_receive_skb is paused + again, which is what the following disable_hist event does by + creating a similar setup on the sched_process_exit event, using the + filter 'comm==wget': + + # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + Whenever a process exits and the comm field of the disable_hist + trigger filter matches 'comm==wget', the netif_receive_skb hist + trigger is disabled. + + The overall effect is that netif_receive_skb events are aggregated + into the hash table for only the duration of the wget. Executing a + wget command and then listing the 'hist' file will display the + output generated by the wget command: + + $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] + + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_receive+0xc8/0x100 + ieee80211_deliver_skb+0xd6/0x270 [mac80211] + ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] + ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] + ieee80211_rx+0x31d/0x900 [mac80211] + iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] + iwl_rx_dispatch+0x8e/0xf0 [iwldvm] + iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + ret_from_fork+0x42/0x70 + } hitcount: 85 len: 28884 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_complete+0xa4/0xe0 + dev_gro_receive+0x23a/0x360 + napi_gro_receive+0x30/0x100 + ieee80211_deliver_skb+0xd6/0x270 [mac80211] + ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] + ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] + ieee80211_rx+0x31d/0x900 [mac80211] + iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] + iwl_rx_dispatch+0x8e/0xf0 [iwldvm] + iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + } hitcount: 98 len: 664329 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + process_backlog+0xa8/0x150 + net_rx_action+0x15d/0x340 + __do_softirq+0x114/0x2c0 + do_softirq_own_stack+0x1c/0x30 + do_softirq+0x65/0x70 + __local_bh_enable_ip+0xb5/0xc0 + ip_finish_output+0x1f4/0x840 + ip_output+0x6b/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x173/0x2a0 + udp_sendmsg+0x2bf/0x9f0 + inet_sendmsg+0x64/0xa0 + sock_sendmsg+0x3d/0x50 + } hitcount: 115 len: 13030 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_complete+0xa4/0xe0 + napi_gro_flush+0x6d/0x90 + iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + ret_from_fork+0x42/0x70 + } hitcount: 934 len: 5512212 + + Totals: + Hits: 1232 + Entries: 4 + Dropped: 0 + + The above shows all the netif_receive_skb callpaths and their total + lengths for the duration of the wget command. + + The 'clear' hist trigger param can be used to clear the hash table. + Suppose we wanted to try another run of the previous example but + this time also wanted to see the complete list of events that went + into the histogram. In order to avoid having to set everything up + again, we can just clear the histogram first: + + # echo 'hist:key=stacktrace:vals=len:clear' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + Just to verify that it is in fact cleared, here's what we now see in + the hist file: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 + + Since we want to see the detailed list of every netif_receive_skb + event occurring during the new run, which are in fact the same + events being aggregated into the hash table, we add some additional + 'enable_event' events to the triggering sched_process_exec and + sched_process_exit events as such: + + # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + # echo 'disable_event:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + If you read the trigger files for the sched_process_exec and + sched_process_exit triggers, you should see two triggers for each: + one enabling/disabling the hist aggregation and the other + enabling/disabling the logging of events: + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget + enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + enable_event:net:netif_receive_skb:unlimited if comm==wget + disable_hist:net:netif_receive_skb:unlimited if comm==wget + + In other words, whenever either of the sched_process_exec or + sched_process_exit events is hit and matches 'wget', it enables or + disables both the histogram and the event log, and what you end up + with is a hash table and set of events just covering the specified + duration. Run the wget command again: + + $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz + + Displaying the 'hist' file should show something similar to what you + saw in the last run, but this time you should also see the + individual events in the trace file: + + # cat /sys/kernel/debug/tracing/trace + + # tracer: nop + # + # entries-in-buffer/entries-written: 183/1426 #P:4 + # + # _-----=> irqs-off + # / _----=> need-resched + # | / _---=> hardirq/softirq + # || / _--=> preempt-depth + # ||| / delay + # TASK-PID CPU# |||| TIMESTAMP FUNCTION + # | | | |||| | | + wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60 + wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60 + dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130 + dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138 + ##### CPU 2 buffer started #### + irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500 + irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500 + . + . + . + + The following example demonstrates how multiple hist triggers can be + attached to a given event. This capability can be useful for + creating a set of different summaries derived from the same set of + events, or for comparing the effects of different filters, among + other things. + + # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=len:vals=common_preempt_count' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + The above set of commands create four triggers differing only in + their filters, along with a completely different though fairly + nonsensical trigger. Note that in order to append multiple hist + triggers to the same file, you should use the '>>' operator to + append them ('>' will also add the new hist trigger, but will remove + any existing hist triggers beforehand). + + Displaying the contents of the 'hist' file for the event shows the + contents of all five histograms: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + + # event histogram + # + # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active] + # + + { len: 176 } hitcount: 1 common_preempt_count: 0 + { len: 223 } hitcount: 1 common_preempt_count: 0 + { len: 4854 } hitcount: 1 common_preempt_count: 0 + { len: 395 } hitcount: 1 common_preempt_count: 0 + { len: 177 } hitcount: 1 common_preempt_count: 0 + { len: 446 } hitcount: 1 common_preempt_count: 0 + { len: 1601 } hitcount: 1 common_preempt_count: 0 + . + . + . + { len: 1280 } hitcount: 66 common_preempt_count: 0 + { len: 116 } hitcount: 81 common_preempt_count: 40 + { len: 708 } hitcount: 112 common_preempt_count: 0 + { len: 46 } hitcount: 221 common_preempt_count: 0 + { len: 1264 } hitcount: 458 common_preempt_count: 0 + + Totals: + Hits: 1428 + Entries: 147 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130 + { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280 + { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280 + { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115 + { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46 + { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118 + { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60 + { skbaddr: ffff880100065900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116 + { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280 + { skbaddr: ffff880100064700 } hitcount: 1 len: 365 + { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60 + . + . + . + { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677 + { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052 + { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589 + { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326 + { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678 + { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678 + { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589 + { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307 + { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032 + + Totals: + Hits: 1451 + Entries: 318 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active] + # + + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active] + # + + { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492 + { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212 + { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854 + { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636 + { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924 + { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356 + { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420 + { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996 + + Totals: + Hits: 14 + Entries: 12 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active] + # + + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 + + Named triggers can be used to have triggers share a common set of + histogram data. This capability is mostly useful for combining the + output of events generated by tracepoints contained inside inline + functions, but names can be used in a hist trigger on any event. + For example, these two triggers when hit will update the same 'len' + field in the shared 'foo' histogram data: + + # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + You can see that they're updating common histogram data by reading + each event's hist files at the same time: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist; + cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # event histogram + # + # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 + { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 + { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 + { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 + { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 + { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 + { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 + { skbaddr: ffff880064505000 } hitcount: 1 len: 46 + { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 + { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 + { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 + { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 + { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 + { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 + { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 + { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 + { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 + { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 + { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 + { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 + { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 + { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 + { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 + { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 + { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 + { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 + { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 + { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 + { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 + { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 + { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 + { skbaddr: ffff880064504400 } hitcount: 4 len: 184 + { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 + { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 + { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 + { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 + { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 + + Totals: + Hits: 81 + Entries: 42 + Dropped: 0 + # event histogram + # + # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 + { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 + { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 + { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 + { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 + { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 + { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 + { skbaddr: ffff880064505000 } hitcount: 1 len: 46 + { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 + { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 + { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 + { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 + { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 + { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 + { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 + { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 + { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 + { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 + { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 + { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 + { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 + { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 + { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 + { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 + { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 + { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 + { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 + { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 + { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 + { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 + { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 + { skbaddr: ffff880064504400 } hitcount: 4 len: 184 + { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 + { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 + { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 + { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 + { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 + + Totals: + Hits: 81 + Entries: 42 + Dropped: 0 + + And here's an example that shows how to combine histogram data from + any two events even if they don't share any 'compatible' fields + other than 'hitcount' and 'stacktrace'. These commands create a + couple of triggers named 'bar' using those fields: + + # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + And displaying the output of either shows some interesting if + somewhat confusing output: + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # event histogram + # + # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active] + # + + { stacktrace: + _do_fork+0x18e/0x330 + kernel_thread+0x29/0x30 + kthreadd+0x154/0x1b0 + ret_from_fork+0x3f/0x70 + } hitcount: 1 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx_ni+0x20/0x70 + dev_loopback_xmit+0xaa/0xd0 + ip_mc_output+0x126/0x240 + ip_local_out_sk+0x31/0x40 + igmp_send_report+0x1e9/0x230 + igmp_timer_expire+0xe9/0x120 + call_timer_fn+0x39/0xf0 + run_timer_softirq+0x1e1/0x290 + __do_softirq+0xfd/0x290 + irq_exit+0x98/0xb0 + smp_apic_timer_interrupt+0x4a/0x60 + apic_timer_interrupt+0x6d/0x80 + cpuidle_enter+0x17/0x20 + call_cpuidle+0x3b/0x60 + cpu_startup_entry+0x22d/0x310 + } hitcount: 1 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx_ni+0x20/0x70 + dev_loopback_xmit+0xaa/0xd0 + ip_mc_output+0x17f/0x240 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x13e/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + SYSC_sendto+0xef/0x170 + SyS_sendto+0xe/0x10 + entry_SYSCALL_64_fastpath+0x12/0x6a + } hitcount: 2 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + ___sys_sendmsg+0x14e/0x270 + } hitcount: 76 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + ___sys_sendmsg+0x269/0x270 + } hitcount: 77 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + SYSC_sendto+0xef/0x170 + } hitcount: 88 + { stacktrace: + _do_fork+0x18e/0x330 + SyS_clone+0x19/0x20 + entry_SYSCALL_64_fastpath+0x12/0x6a + } hitcount: 244 + + Totals: + Hits: 489 + Entries: 7 + Dropped: 0 + + +2.2 Inter-event hist triggers +----------------------------- + +Inter-event hist triggers are hist triggers that combine values from +one or more other events and create a histogram using that data. Data +from an inter-event histogram can in turn become the source for +further combined histograms, thus providing a chain of related +histograms, which is important for some applications. + +The most important example of an inter-event quantity that can be used +in this manner is latency, which is simply a difference in timestamps +between two events. Although latency is the most important +inter-event quantity, note that because the support is completely +general across the trace event subsystem, any event field can be used +in an inter-event quantity. + +An example of a histogram that combines data from other histograms +into a useful chain would be a 'wakeupswitch latency' histogram that +combines a 'wakeup latency' histogram and a 'switch latency' +histogram. + +Normally, a hist trigger specification consists of a (possibly +compound) key along with one or more numeric values, which are +continually updated sums associated with that key. A histogram +specification in this case consists of individual key and value +specifications that refer to trace event fields associated with a +single event type. + +The inter-event hist trigger extension allows fields from multiple +events to be referenced and combined into a multi-event histogram +specification. In support of this overall goal, a few enabling +features have been added to the hist trigger support: + + - In order to compute an inter-event quantity, a value from one + event needs to saved and then referenced from another event. This + requires the introduction of support for histogram 'variables'. + + - The computation of inter-event quantities and their combination + require some minimal amount of support for applying simple + expressions to variables (+ and -). + + - A histogram consisting of inter-event quantities isn't logically a + histogram on either event (so having the 'hist' file for either + event host the histogram output doesn't really make sense). To + address the idea that the histogram is associated with a + combination of events, support is added allowing the creation of + 'synthetic' events that are events derived from other events. + These synthetic events are full-fledged events just like any other + and can be used as such, as for instance to create the + 'combination' histograms mentioned previously. + + - A set of 'actions' can be associated with histogram entries - + these can be used to generate the previously mentioned synthetic + events, but can also be used for other purposes, such as for + example saving context when a 'max' latency has been hit. + + - Trace events don't have a 'timestamp' associated with them, but + there is an implicit timestamp saved along with an event in the + underlying ftrace ring buffer. This timestamp is now exposed as a + a synthetic field named 'common_timestamp' which can be used in + histograms as if it were any other event field; it isn't an actual + field in the trace format but rather is a synthesized value that + nonetheless can be used as if it were an actual field. By default + it is in units of nanoseconds; appending '.usecs' to a + common_timestamp field changes the units to microseconds. + +A note on inter-event timestamps: If common_timestamp is used in a +histogram, the trace buffer is automatically switched over to using +absolute timestamps and the "global" trace clock, in order to avoid +bogus timestamp differences with other clocks that aren't coherent +across CPUs. This can be overridden by specifying one of the other +trace clocks instead, using the "clock=XXX" hist trigger attribute, +where XXX is any of the clocks listed in the tracing/trace_clock +pseudo-file. + +These features are described in more detail in the following sections. + +2.2.1 Histogram Variables +------------------------- + +Variables are simply named locations used for saving and retrieving +values between matching events. A 'matching' event is defined as an +event that has a matching key - if a variable is saved for a histogram +entry corresponding to that key, any subsequent event with a matching +key can access that variable. + +A variable's value is normally available to any subsequent event until +it is set to something else by a subsequent event. The one exception +to that rule is that any variable used in an expression is essentially +'read-once' - once it's used by an expression in a subsequent event, +it's reset to its 'unset' state, which means it can't be used again +unless it's set again. This ensures not only that an event doesn't +use an uninitialized variable in a calculation, but that that variable +is used only once and not for any unrelated subsequent match. + +The basic syntax for saving a variable is to simply prefix a unique +variable name not corresponding to any keyword along with an '=' sign +to any event field. + +Either keys or values can be saved and retrieved in this way. This +creates a variable named 'ts0' for a histogram entry with the key +'next_pid': + + # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ... >> \ + event/trigger + +The ts0 variable can be accessed by any subsequent event having the +same pid as 'next_pid'. + +Variable references are formed by prepending the variable name with +the '$' sign. Thus for example, the ts0 variable above would be +referenced as '$ts0' in expressions. + +Because 'vals=' is used, the common_timestamp variable value above +will also be summed as a normal histogram value would (though for a +timestamp it makes little sense). + +The below shows that a key value can also be saved in the same way: + + # echo 'hist:timer_pid=common_pid:key=timer_pid ...' >> event/trigger + +If a variable isn't a key variable or prefixed with 'vals=', the +associated event field will be saved in a variable but won't be summed +as a value: + + # echo 'hist:keys=next_pid:ts1=common_timestamp ... >> event/trigger + +Multiple variables can be assigned at the same time. The below would +result in both ts0 and b being created as variables, with both +common_timestamp and field1 additionally being summed as values: + + # echo 'hist:keys=pid:vals=$ts0,$b:ts0=common_timestamp,b=field1 ... >> \ + event/trigger + +Note that variable assignments can appear either preceding or +following their use. The command below behaves identically to the +command above: + + # echo 'hist:keys=pid:ts0=common_timestamp,b=field1:vals=$ts0,$b ... >> \ + event/trigger + +Any number of variables not bound to a 'vals=' prefix can also be +assigned by simply separating them with colons. Below is the same +thing but without the values being summed in the histogram: + + # echo 'hist:keys=pid:ts0=common_timestamp:b=field1 ... >> event/trigger + +Variables set as above can be referenced and used in expressions on +another event. + +For example, here's how a latency can be calculated: + + # echo 'hist:keys=pid,prio:ts0=common_timestamp ... >> event1/trigger + # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ... >> event2/trigger + +In the first line above, the event's timetamp is saved into the +variable ts0. In the next line, ts0 is subtracted from the second +event's timestamp to produce the latency, which is then assigned into +yet another variable, 'wakeup_lat'. The hist trigger below in turn +makes use of the wakeup_lat variable to compute a combined latency +using the same key and variable from yet another event: + + # echo 'hist:key=pid:wakeupswitch_lat=$wakeup_lat+$switchtime_lat ... >> event3/trigger + +2.2.2 Synthetic Events +---------------------- + +Synthetic events are user-defined events generated from hist trigger +variables or fields associated with one or more other events. Their +purpose is to provide a mechanism for displaying data spanning +multiple events consistent with the existing and already familiar +usage for normal events. + +To define a synthetic event, the user writes a simple specification +consisting of the name of the new event along with one or more +variables and their types, which can be any valid field type, +separated by semicolons, to the tracing/synthetic_events file. + +For instance, the following creates a new event named 'wakeup_latency' +with 3 fields: lat, pid, and prio. Each of those fields is simply a +variable reference to a variable on another event: + + # echo 'wakeup_latency \ + u64 lat; \ + pid_t pid; \ + int prio' >> \ + /sys/kernel/debug/tracing/synthetic_events + +Reading the tracing/synthetic_events file lists all the currently +defined synthetic events, in this case the event defined above: + + # cat /sys/kernel/debug/tracing/synthetic_events + wakeup_latency u64 lat; pid_t pid; int prio + +An existing synthetic event definition can be removed by prepending +the command that defined it with a '!': + + # echo '!wakeup_latency u64 lat pid_t pid int prio' >> \ + /sys/kernel/debug/tracing/synthetic_events + +At this point, there isn't yet an actual 'wakeup_latency' event +instantiated in the event subsytem - for this to happen, a 'hist +trigger action' needs to be instantiated and bound to actual fields +and variables defined on other events (see Section 6.3.3 below). + +Once that is done, an event instance is created, and a histogram can +be defined using it: + + # echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \ + /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger + +The new event is created under the tracing/events/synthetic/ directory +and looks and behaves just like any other event: + + # ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency + enable filter format hist id trigger + +Like any other event, once a histogram is enabled for the event, the +output can be displayed by reading the event's 'hist' file. + +2.2.3 Hist trigger 'actions' +---------------------------- + +A hist trigger 'action' is a function that's executed whenever a +histogram entry is added or updated. + +The default 'action' if no special function is explicity specified is +as it always has been, to simply update the set of values associated +with an entry. Some applications, however, may want to perform +additional actions at that point, such as generate another event, or +compare and save a maximum. + +The following additional actions are available. To specify an action +for a given event, simply specify the action between colons in the +hist trigger specification. + + - onmatch(matching.event).<synthetic_event_name>(param list) + + The 'onmatch(matching.event).<synthetic_event_name>(params)' hist + trigger action is invoked whenever an event matches and the + histogram entry would be added or updated. It causes the named + synthetic event to be generated with the values given in the + 'param list'. The result is the generation of a synthetic event + that consists of the values contained in those variables at the + time the invoking event was hit. + + The 'param list' consists of one or more parameters which may be + either variables or fields defined on either the 'matching.event' + or the target event. The variables or fields specified in the + param list may be either fully-qualified or unqualified. If a + variable is specified as unqualified, it must be unique between + the two events. A field name used as a param can be unqualified + if it refers to the target event, but must be fully qualified if + it refers to the matching event. A fully-qualified name is of the + form 'system.event_name.$var_name' or 'system.event_name.field'. + + The 'matching.event' specification is simply the fully qualified + event name of the event that matches the target event for the + onmatch() functionality, in the form 'system.event_name'. + + Finally, the number and type of variables/fields in the 'param + list' must match the number and types of the fields in the + synthetic event being generated. + + As an example the below defines a simple synthetic event and uses + a variable defined on the sched_wakeup_new event as a parameter + when invoking the synthetic event. Here we define the synthetic + event: + + # echo 'wakeup_new_test pid_t pid' >> \ + /sys/kernel/debug/tracing/synthetic_events + + # cat /sys/kernel/debug/tracing/synthetic_events + wakeup_new_test pid_t pid + + The following hist trigger both defines the missing testpid + variable and specifies an onmatch() action that generates a + wakeup_new_test synthetic event whenever a sched_wakeup_new event + occurs, which because of the 'if comm == "cyclictest"' filter only + happens when the executable is cyclictest: + + # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\ + wakeup_new_test($testpid) if comm=="cyclictest"' >> \ + /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger + + Creating and displaying a histogram based on those events is now + just a matter of using the fields and new synthetic event in the + tracing/events/synthetic directory, as usual: + + # echo 'hist:keys=pid:sort=pid' >> \ + /sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/trigger + + Running 'cyclictest' should cause wakeup_new events to generate + wakeup_new_test synthetic events which should result in histogram + output in the wakeup_new_test event's hist file: + + # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/hist + + A more typical usage would be to use two events to calculate a + latency. The following example uses a set of hist triggers to + produce a 'wakeup_latency' histogram: + + First, we define a 'wakeup_latency' synthetic event: + + # echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \ + /sys/kernel/debug/tracing/synthetic_events + + Next, we specify that whenever we see a sched_waking event for a + cyclictest thread, save the timestamp in a 'ts0' variable: + + # echo 'hist:keys=$saved_pid:saved_pid=pid:ts0=common_timestamp.usecs \ + if comm=="cyclictest"' >> \ + /sys/kernel/debug/tracing/events/sched/sched_waking/trigger + + Then, when the corresponding thread is actually scheduled onto the + CPU by a sched_switch event, calculate the latency and use that + along with another variable and an event field to generate a + wakeup_latency synthetic event: + + # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:\ + onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,\ + $saved_pid,next_prio) if next_comm=="cyclictest"' >> \ + /sys/kernel/debug/tracing/events/sched/sched_switch/trigger + + We also need to create a histogram on the wakeup_latency synthetic + event in order to aggregate the generated synthetic event data: + + # echo 'hist:keys=pid,prio,lat:sort=pid,lat' >> \ + /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger + + Finally, once we've run cyclictest to actually generate some + events, we can see the output by looking at the wakeup_latency + synthetic event's hist file: + + # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist + + - onmax(var).save(field,.. .) + + The 'onmax(var).save(field,...)' hist trigger action is invoked + whenever the value of 'var' associated with a histogram entry + exceeds the current maximum contained in that variable. + + The end result is that the trace event fields specified as the + onmax.save() params will be saved if 'var' exceeds the current + maximum for that hist trigger entry. This allows context from the + event that exhibited the new maximum to be saved for later + reference. When the histogram is displayed, additional fields + displaying the saved values will be printed. + + As an example the below defines a couple of hist triggers, one for + sched_waking and another for sched_switch, keyed on pid. Whenever + a sched_waking occurs, the timestamp is saved in the entry + corresponding to the current pid, and when the scheduler switches + back to that pid, the timestamp difference is calculated. If the + resulting latency, stored in wakeup_lat, exceeds the current + maximum latency, the values specified in the save() fields are + recoreded: + + # echo 'hist:keys=pid:ts0=common_timestamp.usecs \ + if comm=="cyclictest"' >> \ + /sys/kernel/debug/tracing/events/sched/sched_waking/trigger + + # echo 'hist:keys=next_pid:\ + wakeup_lat=common_timestamp.usecs-$ts0:\ + onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \ + if next_comm=="cyclictest"' >> \ + /sys/kernel/debug/tracing/events/sched/sched_switch/trigger + + When the histogram is displayed, the max value and the saved + values corresponding to the max are displayed following the rest + of the fields: + + # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist + { next_pid: 2255 } hitcount: 239 + common_timestamp-ts0: 0 + max: 27 + next_comm: cyclictest + prev_pid: 0 prev_prio: 120 prev_comm: swapper/1 + + { next_pid: 2256 } hitcount: 2355 + common_timestamp-ts0: 0 + max: 49 next_comm: cyclictest + prev_pid: 0 prev_prio: 120 prev_comm: swapper/0 + + Totals: + Hits: 12970 + Entries: 2 + Dropped: 0 diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 7d9eb39fa76a..a0233edc0718 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -34,10 +34,12 @@ struct ring_buffer_event { * array[0] = time delta (28 .. 59) * size = 8 bytes * - * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock - * array[0] = tv_nsec - * array[1..2] = tv_sec - * size = 16 bytes + * @RINGBUF_TYPE_TIME_STAMP: Absolute timestamp + * Same format as TIME_EXTEND except that the + * value is an absolute timestamp, not a delta + * event.time_delta contains bottom 27 bits + * array[0] = top (28 .. 59) bits + * size = 8 bytes * * <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX: * Data record @@ -54,12 +56,12 @@ enum ring_buffer_type { RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28, RINGBUF_TYPE_PADDING, RINGBUF_TYPE_TIME_EXTEND, - /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */ RINGBUF_TYPE_TIME_STAMP, }; unsigned ring_buffer_event_length(struct ring_buffer_event *event); void *ring_buffer_event_data(struct ring_buffer_event *event); +u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event); /* * ring_buffer_discard_commit will remove an event that has not @@ -115,6 +117,9 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer, int ring_buffer_write(struct ring_buffer *buffer, unsigned long length, void *data); +void ring_buffer_nest_start(struct ring_buffer *buffer); +void ring_buffer_nest_end(struct ring_buffer *buffer); + struct ring_buffer_event * ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, unsigned long *lost_events); @@ -178,6 +183,8 @@ void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, int cpu, u64 *ts); void ring_buffer_set_clock(struct ring_buffer *buffer, u64 (*clock)(void)); +void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs); +bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer); size_t ring_buffer_page_len(void *page); diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index e0e98000b665..2bde3eff564c 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -430,11 +430,13 @@ enum event_trigger_type { extern int filter_match_preds(struct event_filter *filter, void *rec); -extern enum event_trigger_type event_triggers_call(struct trace_event_file *file, - void *rec); -extern void event_triggers_post_call(struct trace_event_file *file, - enum event_trigger_type tt, - void *rec); +extern enum event_trigger_type +event_triggers_call(struct trace_event_file *file, void *rec, + struct ring_buffer_event *event); +extern void +event_triggers_post_call(struct trace_event_file *file, + enum event_trigger_type tt, + void *rec, struct ring_buffer_event *event); bool trace_event_ignore_this_pid(struct trace_event_file *trace_file); @@ -454,7 +456,7 @@ trace_trigger_soft_disabled(struct trace_event_file *file) if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) { if (eflags & EVENT_FILE_FL_TRIGGER_MODE) - event_triggers_call(file, NULL); + event_triggers_call(file, NULL, NULL); if (eflags & EVENT_FILE_FL_SOFT_DISABLED) return true; if (eflags & EVENT_FILE_FL_PID_FILTER) diff --git a/include/trace/events/initcall.h b/include/trace/events/initcall.h new file mode 100644 index 000000000000..8d6cf10d27c9 --- /dev/null +++ b/include/trace/events/initcall.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM initcall + +#if !defined(_TRACE_INITCALL_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_INITCALL_H + +#include <linux/tracepoint.h> + +TRACE_EVENT(initcall_level, + + TP_PROTO(const char *level), + + TP_ARGS(level), + + TP_STRUCT__entry( + __string(level, level) + ), + + TP_fast_assign( + __assign_str(level, level); + ), + + TP_printk("level=%s", __get_str(level)) +); + +TRACE_EVENT(initcall_start, + + TP_PROTO(initcall_t func), + + TP_ARGS(func), + + TP_STRUCT__entry( + __field(initcall_t, func) + ), + + TP_fast_assign( + __entry->func = func; + ), + + TP_printk("func=%pS", __entry->func) +); + +TRACE_EVENT(initcall_finish, + + TP_PROTO(initcall_t func, int ret), + + TP_ARGS(func, ret), + + TP_STRUCT__entry( + __field(initcall_t, func) + __field(int, ret) + ), + + TP_fast_assign( + __entry->func = func; + __entry->ret = ret; + ), + + TP_printk("func=%pS ret=%d", __entry->func, __entry->ret) +); + +#endif /* if !defined(_TRACE_GPIO_H) || defined(TRACE_HEADER_MULTI_READ) */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/init/main.c b/init/main.c index e4a3160991ea..d499f4a80e0b 100644 --- a/init/main.c +++ b/init/main.c @@ -97,6 +97,9 @@ #include <asm/sections.h> #include <asm/cacheflush.h> +#define CREATE_TRACE_POINTS +#include <trace/events/initcall.h> + static int kernel_init(void *); extern void init_IRQ(void); @@ -491,6 +494,17 @@ void __init __weak thread_stack_cache_init(void) void __init __weak mem_encrypt_init(void) { } +bool initcall_debug; +core_param(initcall_debug, initcall_debug, bool, 0644); + +#ifdef TRACEPOINTS_ENABLED +static void __init initcall_debug_enable(void); +#else +static inline void initcall_debug_enable(void) +{ +} +#endif + /* * Set up kernel memory allocators */ @@ -612,6 +626,9 @@ asmlinkage __visible void __init start_kernel(void) /* Trace events are available after this */ trace_init(); + if (initcall_debug) + initcall_debug_enable(); + context_tracking_init(); /* init some links before init_ISA_irqs() */ early_irq_init(); @@ -728,9 +745,6 @@ static void __init do_ctors(void) #endif } -bool initcall_debug; -core_param(initcall_debug, initcall_debug, bool, 0644); - #ifdef CONFIG_KALLSYMS struct blacklist_entry { struct list_head next; @@ -800,37 +814,71 @@ static bool __init_or_module initcall_blacklisted(initcall_t fn) #endif __setup("initcall_blacklist=", initcall_blacklist); -static int __init_or_module do_one_initcall_debug(initcall_t fn) +static __init_or_module void +trace_initcall_start_cb(void *data, initcall_t fn) { - ktime_t calltime, delta, rettime; - unsigned long long duration; - int ret; + ktime_t *calltime = (ktime_t *)data; printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); - calltime = ktime_get(); - ret = fn(); + *calltime = ktime_get(); +} + +static __init_or_module void +trace_initcall_finish_cb(void *data, initcall_t fn, int ret) +{ + ktime_t *calltime = (ktime_t *)data; + ktime_t delta, rettime; + unsigned long long duration; + rettime = ktime_get(); - delta = ktime_sub(rettime, calltime); + delta = ktime_sub(rettime, *calltime); duration = (unsigned long long) ktime_to_ns(delta) >> 10; printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn, ret, duration); +} - return ret; +static ktime_t initcall_calltime; + +#ifdef TRACEPOINTS_ENABLED +static void __init initcall_debug_enable(void) +{ + int ret; + + ret = register_trace_initcall_start(trace_initcall_start_cb, + &initcall_calltime); + ret |= register_trace_initcall_finish(trace_initcall_finish_cb, + &initcall_calltime); + WARN(ret, "Failed to register initcall tracepoints\n"); } +# define do_trace_initcall_start trace_initcall_start +# define do_trace_initcall_finish trace_initcall_finish +#else +static inline void do_trace_initcall_start(initcall_t fn) +{ + if (!initcall_debug) + return; + trace_initcall_start_cb(&initcall_calltime, fn); +} +static inline void do_trace_initcall_finish(initcall_t fn, int ret) +{ + if (!initcall_debug) + return; + trace_initcall_finish_cb(&initcall_calltime, fn, ret); +} +#endif /* !TRACEPOINTS_ENABLED */ int __init_or_module do_one_initcall(initcall_t fn) { int count = preempt_count(); - int ret; char msgbuf[64]; + int ret; if (initcall_blacklisted(fn)) return -EPERM; - if (initcall_debug) - ret = do_one_initcall_debug(fn); - else - ret = fn(); + do_trace_initcall_start(fn); + ret = fn(); + do_trace_initcall_finish(fn, ret); msgbuf[0] = 0; @@ -874,7 +922,7 @@ static initcall_t *initcall_levels[] __initdata = { /* Keep these in sync with initcalls in include/linux/init.h */ static char *initcall_level_names[] __initdata = { - "early", + "pure", "core", "postcore", "arch", @@ -895,6 +943,7 @@ static void __init do_initcall_level(int level) level, level, NULL, &repair_env_string); + trace_initcall_level(initcall_level_names[level]); for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) do_one_initcall(*fn); } @@ -929,6 +978,7 @@ static void __init do_pre_smp_initcalls(void) { initcall_t *fn; + trace_initcall_level("early"); for (fn = __initcall_start; fn < __initcall0_start; fn++) do_one_initcall(*fn); } diff --git a/kernel/panic.c b/kernel/panic.c index 9d833d913c84..6c3b08cd1139 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -554,6 +554,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint, else dump_stack(); + print_irqtrace_events(current); + print_oops_end_marker(); /* Just a warning, don't kill lockdep. */ diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 704e55129c3a..2f4af216bd6e 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -51,6 +51,7 @@ #include <linux/uaccess.h> #include <asm/sections.h> +#include <trace/events/initcall.h> #define CREATE_TRACE_POINTS #include <trace/events/printk.h> @@ -2780,6 +2781,7 @@ EXPORT_SYMBOL(unregister_console); */ void __init console_init(void) { + int ret; initcall_t *call; /* Setup the default TTY line discipline. */ @@ -2790,8 +2792,11 @@ void __init console_init(void) * inform about problems etc.. */ call = __con_initcall_start; + trace_initcall_level("console"); while (call < __con_initcall_end) { - (*call)(); + trace_initcall_start((*call)); + ret = (*call)(); + trace_initcall_finish((*call), ret); call++; } } diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 0b249e2f0c3c..c4f0f2e4126e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -606,7 +606,10 @@ config HIST_TRIGGERS event activity as an initial guide for further investigation using more advanced tools. - See Documentation/trace/events.txt. + Inter-event tracing of quantities such as latencies is also + supported using hist triggers under this option. + + See Documentation/trace/histogram.txt. If in doubt, say N. config MMIOTRACE_TEST diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index eac9ce2c57a2..16bbf062018f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3902,14 +3902,13 @@ static bool module_exists(const char *module) { /* All modules have the symbol __this_module */ const char this_mod[] = "__this_module"; - const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1; - char modname[modname_size + 1]; + char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; unsigned long val; int n; - n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod); + n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); - if (n > modname_size) + if (n > sizeof(modname) - 1) return false; val = module_kallsyms_lookup_name(modname); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index dcf1c4dd3efe..c9cb9767d49b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -22,6 +22,7 @@ #include <linux/hash.h> #include <linux/list.h> #include <linux/cpu.h> +#include <linux/oom.h> #include <asm/local.h> @@ -41,6 +42,8 @@ int ring_buffer_print_entry_header(struct trace_seq *s) RINGBUF_TYPE_PADDING); trace_seq_printf(s, "\ttime_extend : type == %d\n", RINGBUF_TYPE_TIME_EXTEND); + trace_seq_printf(s, "\ttime_stamp : type == %d\n", + RINGBUF_TYPE_TIME_STAMP); trace_seq_printf(s, "\tdata max type_len == %d\n", RINGBUF_TYPE_DATA_TYPE_LEN_MAX); @@ -140,12 +143,15 @@ int ring_buffer_print_entry_header(struct trace_seq *s) enum { RB_LEN_TIME_EXTEND = 8, - RB_LEN_TIME_STAMP = 16, + RB_LEN_TIME_STAMP = 8, }; #define skip_time_extend(event) \ ((struct ring_buffer_event *)((char *)event + RB_LEN_TIME_EXTEND)) +#define extended_time(event) \ + (event->type_len >= RINGBUF_TYPE_TIME_EXTEND) + static inline int rb_null_event(struct ring_buffer_event *event) { return event->type_len == RINGBUF_TYPE_PADDING && !event->time_delta; @@ -209,7 +215,7 @@ rb_event_ts_length(struct ring_buffer_event *event) { unsigned len = 0; - if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) { + if (extended_time(event)) { /* time extends include the data event after it */ len = RB_LEN_TIME_EXTEND; event = skip_time_extend(event); @@ -231,7 +237,7 @@ unsigned ring_buffer_event_length(struct ring_buffer_event *event) { unsigned length; - if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) + if (extended_time(event)) event = skip_time_extend(event); length = rb_event_length(event); @@ -248,7 +254,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_length); static __always_inline void * rb_event_data(struct ring_buffer_event *event) { - if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) + if (extended_time(event)) event = skip_time_extend(event); BUG_ON(event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX); /* If length is in len field, then array[0] has the data */ @@ -275,6 +281,27 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); #define TS_MASK ((1ULL << TS_SHIFT) - 1) #define TS_DELTA_TEST (~TS_MASK) +/** + * ring_buffer_event_time_stamp - return the event's extended timestamp + * @event: the event to get the timestamp of + * + * Returns the extended timestamp associated with a data event. + * An extended time_stamp is a 64-bit timestamp represented + * internally in a special way that makes the best use of space + * contained within a ring buffer event. This function decodes + * it and maps it to a straight u64 value. + */ +u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event) +{ + u64 ts; + + ts = event->array[0]; + ts <<= TS_SHIFT; + ts += event->time_delta; + + return ts; +} + /* Flag when events were overwritten */ #define RB_MISSED_EVENTS (1 << 31) /* Missed count stored at end */ @@ -451,6 +478,7 @@ struct ring_buffer_per_cpu { struct buffer_page *reader_page; unsigned long lost_events; unsigned long last_overrun; + unsigned long nest; local_t entries_bytes; local_t entries; local_t overrun; @@ -488,6 +516,7 @@ struct ring_buffer { u64 (*clock)(void); struct rb_irq_work irq_work; + bool time_stamp_abs; }; struct ring_buffer_iter { @@ -1134,30 +1163,60 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) { struct buffer_page *bpage, *tmp; + bool user_thread = current->mm != NULL; + gfp_t mflags; long i; + /* + * Check if the available memory is there first. + * Note, si_mem_available() only gives us a rough estimate of available + * memory. It may not be accurate. But we don't care, we just want + * to prevent doing any allocation when it is obvious that it is + * not going to succeed. + */ + i = si_mem_available(); + if (i < nr_pages) + return -ENOMEM; + + /* + * __GFP_RETRY_MAYFAIL flag makes sure that the allocation fails + * gracefully without invoking oom-killer and the system is not + * destabilized. + */ + mflags = GFP_KERNEL | __GFP_RETRY_MAYFAIL; + + /* + * If a user thread allocates too much, and si_mem_available() + * reports there's enough memory, even though there is not. + * Make sure the OOM killer kills this thread. This can happen + * even with RETRY_MAYFAIL because another task may be doing + * an allocation after this task has taken all memory. + * This is the task the OOM killer needs to take out during this + * loop, even if it was triggered by an allocation somewhere else. + */ + if (user_thread) + set_current_oom_origin(); for (i = 0; i < nr_pages; i++) { struct page *page; - /* - * __GFP_RETRY_MAYFAIL flag makes sure that the allocation fails - * gracefully without invoking oom-killer and the system is not - * destabilized. - */ + bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), - GFP_KERNEL | __GFP_RETRY_MAYFAIL, - cpu_to_node(cpu)); + mflags, cpu_to_node(cpu)); if (!bpage) goto free_pages; list_add(&bpage->list, pages); - page = alloc_pages_node(cpu_to_node(cpu), - GFP_KERNEL | __GFP_RETRY_MAYFAIL, 0); + page = alloc_pages_node(cpu_to_node(cpu), mflags, 0); if (!page) goto free_pages; bpage->page = page_address(page); rb_init_page(bpage->page); + + if (user_thread && fatal_signal_pending(current)) + goto free_pages; } + if (user_thread) + clear_current_oom_origin(); return 0; @@ -1166,6 +1225,8 @@ free_pages: list_del_init(&bpage->list); free_buffer_page(bpage); } + if (user_thread) + clear_current_oom_origin(); return -ENOMEM; } @@ -1382,6 +1443,16 @@ void ring_buffer_set_clock(struct ring_buffer *buffer, buffer->clock = clock; } +void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs) +{ + buffer->time_stamp_abs = abs; +} + +bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer) +{ + return buffer->time_stamp_abs; +} + static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer); static inline unsigned long rb_page_entries(struct buffer_page *bpage) @@ -2206,12 +2277,15 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer, /* Slow path, do not inline */ static noinline struct ring_buffer_event * -rb_add_time_stamp(struct ring_buffer_event *event, u64 delta) +rb_add_time_stamp(struct ring_buffer_event *event, u64 delta, bool abs) { - event->type_len = RINGBUF_TYPE_TIME_EXTEND; + if (abs) + event->type_len = RINGBUF_TYPE_TIME_STAMP; + else + event->type_len = RINGBUF_TYPE_TIME_EXTEND; - /* Not the first event on the page? */ - if (rb_event_index(event)) { + /* Not the first event on the page, or not delta? */ + if (abs || rb_event_index(event)) { event->time_delta = delta & TS_MASK; event->array[0] = delta >> TS_SHIFT; } else { @@ -2254,7 +2328,9 @@ rb_update_event(struct ring_buffer_per_cpu *cpu_buffer, * add it to the start of the resevered space. */ if (unlikely(info->add_timestamp)) { - event = rb_add_time_stamp(event, delta); + bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer); + + event = rb_add_time_stamp(event, info->delta, abs); length -= RB_LEN_TIME_EXTEND; delta = 0; } @@ -2442,7 +2518,7 @@ static __always_inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer static inline void rb_event_discard(struct ring_buffer_event *event) { - if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) + if (extended_time(event)) event = skip_time_extend(event); /* array[0] holds the actual length for the discarded event */ @@ -2486,10 +2562,11 @@ rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer, cpu_buffer->write_stamp = cpu_buffer->commit_page->page->time_stamp; else if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) { - delta = event->array[0]; - delta <<= TS_SHIFT; - delta += event->time_delta; + delta = ring_buffer_event_time_stamp(event); cpu_buffer->write_stamp += delta; + } else if (event->type_len == RINGBUF_TYPE_TIME_STAMP) { + delta = ring_buffer_event_time_stamp(event); + cpu_buffer->write_stamp = delta; } else cpu_buffer->write_stamp += event->time_delta; } @@ -2581,10 +2658,10 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer) bit = pc & NMI_MASK ? RB_CTX_NMI : pc & HARDIRQ_MASK ? RB_CTX_IRQ : RB_CTX_SOFTIRQ; - if (unlikely(val & (1 << bit))) + if (unlikely(val & (1 << (bit + cpu_buffer->nest)))) return 1; - val |= (1 << bit); + val |= (1 << (bit + cpu_buffer->nest)); cpu_buffer->current_context = val; return 0; @@ -2593,7 +2670,57 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer) static __always_inline void trace_recursive_unlock(struct ring_buffer_per_cpu *cpu_buffer) { - cpu_buffer->current_context &= cpu_buffer->current_context - 1; + cpu_buffer->current_context &= + cpu_buffer->current_context - (1 << cpu_buffer->nest); +} + +/* The recursive locking above uses 4 bits */ +#define NESTED_BITS 4 + +/** + * ring_buffer_nest_start - Allow to trace while nested + * @buffer: The ring buffer to modify + * + * The ring buffer has a safty mechanism to prevent recursion. + * But there may be a case where a trace needs to be done while + * tracing something else. In this case, calling this function + * will allow this function to nest within a currently active + * ring_buffer_lock_reserve(). + * + * Call this function before calling another ring_buffer_lock_reserve() and + * call ring_buffer_nest_end() after the nested ring_buffer_unlock_commit(). + */ +void ring_buffer_nest_start(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + /* Enabled by ring_buffer_nest_end() */ + preempt_disable_notrace(); + cpu = raw_smp_processor_id(); + cpu_buffer = buffer->buffers[cpu]; + /* This is the shift value for the above recusive locking */ + cpu_buffer->nest += NESTED_BITS; +} + +/** + * ring_buffer_nest_end - Allow to trace while nested + * @buffer: The ring buffer to modify + * + * Must be called after ring_buffer_nest_start() and after the + * ring_buffer_unlock_commit(). + */ +void ring_buffer_nest_end(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + /* disabled by ring_buffer_nest_start() */ + cpu = raw_smp_processor_id(); + cpu_buffer = buffer->buffers[cpu]; + /* This is the shift value for the above recusive locking */ + cpu_buffer->nest -= NESTED_BITS; + preempt_enable_notrace(); } /** @@ -2637,7 +2764,8 @@ rb_handle_timestamp(struct ring_buffer_per_cpu *cpu_buffer, sched_clock_stable() ? "" : "If you just came from a suspend/resume,\n" "please switch to the trace global clock:\n" - " echo global > /sys/kernel/debug/tracing/trace_clock\n"); + " echo global > /sys/kernel/debug/tracing/trace_clock\n" + "or add trace_clock=global to the kernel command line\n"); info->add_timestamp = 1; } @@ -2669,7 +2797,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, * If this is the first commit on the page, then it has the same * timestamp as the page itself. */ - if (!tail) + if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer)) info->delta = 0; /* See if we shot pass the end of this buffer page */ @@ -2746,8 +2874,11 @@ rb_reserve_next_event(struct ring_buffer *buffer, /* make sure this diff is calculated here */ barrier(); - /* Did the write stamp get updated already? */ - if (likely(info.ts >= cpu_buffer->write_stamp)) { + if (ring_buffer_time_stamp_abs(buffer)) { + info.delta = info.ts; + rb_handle_timestamp(cpu_buffer, &info); + } else /* Did the write stamp get updated already? */ + if (likely(info.ts >= cpu_buffer->write_stamp)) { info.delta = diff; if (unlikely(test_time_stamp(info.delta))) rb_handle_timestamp(cpu_buffer, &info); @@ -3429,14 +3560,13 @@ rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer, return; case RINGBUF_TYPE_TIME_EXTEND: - delta = event->array[0]; - delta <<= TS_SHIFT; - delta += event->time_delta; + delta = ring_buffer_event_time_stamp(event); cpu_buffer->read_stamp += delta; return; case RINGBUF_TYPE_TIME_STAMP: - /* FIXME: not implemented */ + delta = ring_buffer_event_time_stamp(event); + cpu_buffer->read_stamp = delta; return; case RINGBUF_TYPE_DATA: @@ -3460,14 +3590,13 @@ rb_update_iter_read_stamp(struct ring_buffer_iter *iter, return; case RINGBUF_TYPE_TIME_EXTEND: - delta = event->array[0]; - delta <<= TS_SHIFT; - delta += event->time_delta; + delta = ring_buffer_event_time_stamp(event); iter->read_stamp += delta; return; case RINGBUF_TYPE_TIME_STAMP: - /* FIXME: not implemented */ + delta = ring_buffer_event_time_stamp(event); + iter->read_stamp = delta; return; case RINGBUF_TYPE_DATA: @@ -3691,6 +3820,8 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts, struct buffer_page *reader; int nr_loops = 0; + if (ts) + *ts = 0; again: /* * We repeat when a time extend is encountered. @@ -3727,12 +3858,17 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts, goto again; case RINGBUF_TYPE_TIME_STAMP: - /* FIXME: not implemented */ + if (ts) { + *ts = ring_buffer_event_time_stamp(event); + ring_buffer_normalize_time_stamp(cpu_buffer->buffer, + cpu_buffer->cpu, ts); + } + /* Internal data, OK to advance */ rb_advance_reader(cpu_buffer); goto again; case RINGBUF_TYPE_DATA: - if (ts) { + if (ts && !(*ts)) { *ts = cpu_buffer->read_stamp + event->time_delta; ring_buffer_normalize_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu, ts); @@ -3757,6 +3893,9 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts) struct ring_buffer_event *event; int nr_loops = 0; + if (ts) + *ts = 0; + cpu_buffer = iter->cpu_buffer; buffer = cpu_buffer->buffer; @@ -3809,12 +3948,17 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts) goto again; case RINGBUF_TYPE_TIME_STAMP: - /* FIXME: not implemented */ + if (ts) { + *ts = ring_buffer_event_time_stamp(event); + ring_buffer_normalize_time_stamp(cpu_buffer->buffer, + cpu_buffer->cpu, ts); + } + /* Internal data, OK to advance */ rb_advance_iter(iter); goto again; case RINGBUF_TYPE_DATA: - if (ts) { + if (ts && !(*ts)) { *ts = iter->read_stamp + event->time_delta; ring_buffer_normalize_time_stamp(buffer, cpu_buffer->cpu, ts); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5071931eb943..dfbcf9ee1447 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -41,6 +41,7 @@ #include <linux/nmi.h> #include <linux/fs.h> #include <linux/trace.h> +#include <linux/sched/clock.h> #include <linux/sched/rt.h> #include "trace.h" @@ -1168,6 +1169,14 @@ static struct { ARCH_TRACE_CLOCKS }; +bool trace_clock_in_ns(struct trace_array *tr) +{ + if (trace_clocks[tr->clock_id].in_ns) + return true; + + return false; +} + /* * trace_parser_get_init - gets the buffer for trace parser */ @@ -2269,7 +2278,7 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, *current_rb = trace_file->tr->trace_buffer.buffer; - if ((trace_file->flags & + if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && (entry = this_cpu_read(trace_buffered_event))) { /* Try to use the per cpu buffer first */ @@ -4515,6 +4524,9 @@ static const char readme_msg[] = #ifdef CONFIG_X86_64 " x86-tsc: TSC cycle counter\n" #endif + "\n timestamp_mode\t-view the mode used to timestamp events\n" + " delta: Delta difference against a buffer-wide timestamp\n" + " absolute: Absolute (standalone) timestamp\n" "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" "\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n" " tracing_cpumask\t- Limit which CPUs to trace\n" @@ -4691,8 +4703,9 @@ static const char readme_msg[] = "\t .sym display an address as a symbol\n" "\t .sym-offset display an address as a symbol and offset\n" "\t .execname display a common_pid as a program name\n" - "\t .syscall display a syscall id as a syscall name\n\n" - "\t .log2 display log2 value rather than raw number\n\n" + "\t .syscall display a syscall id as a syscall name\n" + "\t .log2 display log2 value rather than raw number\n" + "\t .usecs display a common_timestamp in microseconds\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" @@ -6202,7 +6215,7 @@ static int tracing_clock_show(struct seq_file *m, void *v) return 0; } -static int tracing_set_clock(struct trace_array *tr, const char *clockstr) +int tracing_set_clock(struct trace_array *tr, const char *clockstr) { int i; @@ -6282,6 +6295,71 @@ static int tracing_clock_open(struct inode *inode, struct file *file) return ret; } +static int tracing_time_stamp_mode_show(struct seq_file *m, void *v) +{ + struct trace_array *tr = m->private; + + mutex_lock(&trace_types_lock); + + if (ring_buffer_time_stamp_abs(tr->trace_buffer.buffer)) + seq_puts(m, "delta [absolute]\n"); + else + seq_puts(m, "[delta] absolute\n"); + + mutex_unlock(&trace_types_lock); + + return 0; +} + +static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file) +{ + struct trace_array *tr = inode->i_private; + int ret; + + if (tracing_disabled) + return -ENODEV; + + if (trace_array_get(tr)) + return -ENODEV; + + ret = single_open(file, tracing_time_stamp_mode_show, inode->i_private); + if (ret < 0) + trace_array_put(tr); + + return ret; +} + +int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs) +{ + int ret = 0; + + mutex_lock(&trace_types_lock); + + if (abs && tr->time_stamp_abs_ref++) + goto out; + + if (!abs) { + if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) { + ret = -EINVAL; + goto out; + } + + if (--tr->time_stamp_abs_ref) + goto out; + } + + ring_buffer_set_time_stamp_abs(tr->trace_buffer.buffer, abs); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->max_buffer.buffer) + ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs); +#endif + out: + mutex_unlock(&trace_types_lock); + + return ret; +} + struct ftrace_buffer_info { struct trace_iterator iter; void *spare; @@ -6529,6 +6607,13 @@ static const struct file_operations trace_clock_fops = { .write = tracing_clock_write, }; +static const struct file_operations trace_time_stamp_mode_fops = { + .open = tracing_time_stamp_mode_open, + .read = seq_read, + .llseek = seq_lseek, + .release = tracing_single_release_tr, +}; + #ifdef CONFIG_TRACER_SNAPSHOT static const struct file_operations snapshot_fops = { .open = tracing_snapshot_open, @@ -7699,6 +7784,7 @@ static int instance_mkdir(const char *name) INIT_LIST_HEAD(&tr->systems); INIT_LIST_HEAD(&tr->events); + INIT_LIST_HEAD(&tr->hist_vars); if (allocate_trace_buffers(tr, trace_buf_size) < 0) goto out_free_tr; @@ -7851,6 +7937,9 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("tracing_on", 0644, d_tracer, tr, &rb_simple_fops); + trace_create_file("timestamp_mode", 0444, d_tracer, tr, + &trace_time_stamp_mode_fops); + create_trace_options_dir(tr); #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) @@ -8446,6 +8535,7 @@ __init static int tracer_alloc_buffers(void) INIT_LIST_HEAD(&global_trace.systems); INIT_LIST_HEAD(&global_trace.events); + INIT_LIST_HEAD(&global_trace.hist_vars); list_add(&global_trace.list, &ftrace_trace_arrays); apply_trace_boot_options(); @@ -8507,3 +8597,21 @@ __init static int clear_boot_tracer(void) fs_initcall(tracer_init_tracefs); late_initcall_sync(clear_boot_tracer); + +#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK +__init static int tracing_set_default_clock(void) +{ + /* sched_clock_stable() is determined in late_initcall */ + if (!trace_boot_clock && !sched_clock_stable()) { + printk(KERN_WARNING + "Unstable clock detected, switching default tracing clock to \"global\"\n" + "If you want to keep using the local clock, then add:\n" + " \"trace_clock=local\"\n" + "on the kernel command line\n"); + tracing_set_clock(&global_trace, "global"); + } + + return 0; +} +late_initcall_sync(tracing_set_default_clock); +#endif diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2a6d0325a761..6fb46a06c9dc 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -273,6 +273,8 @@ struct trace_array { /* function tracing enabled */ int function_enabled; #endif + int time_stamp_abs_ref; + struct list_head hist_vars; }; enum { @@ -286,6 +288,11 @@ extern struct mutex trace_types_lock; extern int trace_array_get(struct trace_array *tr); extern void trace_array_put(struct trace_array *tr); +extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs); +extern int tracing_set_clock(struct trace_array *tr, const char *clockstr); + +extern bool trace_clock_in_ns(struct trace_array *tr); + /* * The global tracer (top) should be the first trace array added, * but we check the flag anyway. @@ -1209,12 +1216,11 @@ struct ftrace_event_field { int is_signed; }; +struct prog_entry; + struct event_filter { - int n_preds; /* Number assigned */ - int a_preds; /* allocated */ - struct filter_pred __rcu *preds; - struct filter_pred __rcu *root; - char *filter_string; + struct prog_entry __rcu *prog; + char *filter_string; }; struct event_subsystem { @@ -1291,7 +1297,7 @@ __event_trigger_test_discard(struct trace_event_file *file, unsigned long eflags = file->flags; if (eflags & EVENT_FILE_FL_TRIGGER_COND) - *tt = event_triggers_call(file, entry); + *tt = event_triggers_call(file, entry, event); if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) || (unlikely(file->flags & EVENT_FILE_FL_FILTERED) && @@ -1328,7 +1334,7 @@ event_trigger_unlock_commit(struct trace_event_file *file, trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc); if (tt) - event_triggers_post_call(file, tt, entry); + event_triggers_post_call(file, tt, entry, event); } /** @@ -1361,7 +1367,7 @@ event_trigger_unlock_commit_regs(struct trace_event_file *file, irq_flags, pc, regs); if (tt) - event_triggers_post_call(file, tt, entry); + event_triggers_post_call(file, tt, entry, event); } #define FILTER_PRED_INVALID ((unsigned short)-1) @@ -1406,12 +1412,8 @@ struct filter_pred { unsigned short *ops; struct ftrace_event_field *field; int offset; - int not; + int not; int op; - unsigned short index; - unsigned short parent; - unsigned short left; - unsigned short right; }; static inline bool is_string_field(struct ftrace_event_field *field) @@ -1543,6 +1545,8 @@ extern void pause_named_trigger(struct event_trigger_data *data); extern void unpause_named_trigger(struct event_trigger_data *data); extern void set_named_trigger_data(struct event_trigger_data *data, struct event_trigger_data *named_data); +extern struct event_trigger_data * +get_named_trigger_data(struct event_trigger_data *data); extern int register_event_command(struct event_command *cmd); extern int unregister_event_command(struct event_command *cmd); extern int register_trigger_hist_enable_disable_cmds(void); @@ -1586,7 +1590,8 @@ extern int register_trigger_hist_enable_disable_cmds(void); */ struct event_trigger_ops { void (*func)(struct event_trigger_data *data, - void *rec); + void *rec, + struct ring_buffer_event *rbe); int (*init)(struct event_trigger_ops *ops, struct event_trigger_data *data); void (*free)(struct event_trigger_ops *ops, diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index 5fdc779f411d..d8a188e0418a 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -96,7 +96,7 @@ u64 notrace trace_clock_global(void) int this_cpu; u64 now; - local_irq_save(flags); + raw_local_irq_save(flags); this_cpu = raw_smp_processor_id(); now = sched_clock_cpu(this_cpu); @@ -122,7 +122,7 @@ u64 notrace trace_clock_global(void) arch_spin_unlock(&trace_clock_struct.lock); out: - local_irq_restore(flags); + raw_local_irq_restore(flags); return now; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index a764aec3c9a1..1bda4ec95e18 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -33,163 +33,595 @@ "# Only events with the given fields will be affected.\n" \ "# If no events are modified, an error message will be displayed here" -enum filter_op_ids -{ - OP_OR, - OP_AND, - OP_GLOB, - OP_NE, - OP_EQ, - OP_LT, - OP_LE, - OP_GT, - OP_GE, - OP_BAND, - OP_NOT, - OP_NONE, - OP_OPEN_PAREN, -}; +/* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */ +#define OPS \ + C( OP_GLOB, "~" ), \ + C( OP_NE, "!=" ), \ + C( OP_EQ, "==" ), \ + C( OP_LE, "<=" ), \ + C( OP_LT, "<" ), \ + C( OP_GE, ">=" ), \ + C( OP_GT, ">" ), \ + C( OP_BAND, "&" ), \ + C( OP_MAX, NULL ) -struct filter_op { - int id; - char *string; - int precedence; -}; +#undef C +#define C(a, b) a -/* Order must be the same as enum filter_op_ids above */ -static struct filter_op filter_ops[] = { - { OP_OR, "||", 1 }, - { OP_AND, "&&", 2 }, - { OP_GLOB, "~", 4 }, - { OP_NE, "!=", 4 }, - { OP_EQ, "==", 4 }, - { OP_LT, "<", 5 }, - { OP_LE, "<=", 5 }, - { OP_GT, ">", 5 }, - { OP_GE, ">=", 5 }, - { OP_BAND, "&", 6 }, - { OP_NOT, "!", 6 }, - { OP_NONE, "OP_NONE", 0 }, - { OP_OPEN_PAREN, "(", 0 }, -}; +enum filter_op_ids { OPS }; -enum { - FILT_ERR_NONE, - FILT_ERR_INVALID_OP, - FILT_ERR_UNBALANCED_PAREN, - FILT_ERR_TOO_MANY_OPERANDS, - FILT_ERR_OPERAND_TOO_LONG, - FILT_ERR_FIELD_NOT_FOUND, - FILT_ERR_ILLEGAL_FIELD_OP, - FILT_ERR_ILLEGAL_INTVAL, - FILT_ERR_BAD_SUBSYS_FILTER, - FILT_ERR_TOO_MANY_PREDS, - FILT_ERR_MISSING_FIELD, - FILT_ERR_INVALID_FILTER, - FILT_ERR_IP_FIELD_ONLY, - FILT_ERR_ILLEGAL_NOT_OP, -}; +#undef C +#define C(a, b) b -static char *err_text[] = { - "No error", - "Invalid operator", - "Unbalanced parens", - "Too many operands", - "Operand too long", - "Field not found", - "Illegal operation for field type", - "Illegal integer value", - "Couldn't find or set field in one of a subsystem's events", - "Too many terms in predicate expression", - "Missing field name and/or value", - "Meaningless filter expression", - "Only 'ip' field is supported for function trace", - "Illegal use of '!'", -}; +static const char * ops[] = { OPS }; -struct opstack_op { - enum filter_op_ids op; - struct list_head list; -}; +/* + * pred functions are OP_LE, OP_LT, OP_GE, OP_GT, and OP_BAND + * pred_funcs_##type below must match the order of them above. + */ +#define PRED_FUNC_START OP_LE +#define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START) + +#define ERRORS \ + C(NONE, "No error"), \ + C(INVALID_OP, "Invalid operator"), \ + C(TOO_MANY_OPEN, "Too many '('"), \ + C(TOO_MANY_CLOSE, "Too few '('"), \ + C(MISSING_QUOTE, "Missing matching quote"), \ + C(OPERAND_TOO_LONG, "Operand too long"), \ + C(EXPECT_STRING, "Expecting string field"), \ + C(EXPECT_DIGIT, "Expecting numeric field"), \ + C(ILLEGAL_FIELD_OP, "Illegal operation for field type"), \ + C(FIELD_NOT_FOUND, "Field not found"), \ + C(ILLEGAL_INTVAL, "Illegal integer value"), \ + C(BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \ + C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \ + C(INVALID_FILTER, "Meaningless filter expression"), \ + C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \ + C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), + +#undef C +#define C(a, b) FILT_ERR_##a + +enum { ERRORS }; + +#undef C +#define C(a, b) b + +static char *err_text[] = { ERRORS }; + +/* Called after a '!' character but "!=" and "!~" are not "not"s */ +static bool is_not(const char *str) +{ + switch (str[1]) { + case '=': + case '~': + return false; + } + return true; +} -struct postfix_elt { - enum filter_op_ids op; - char *operand; - struct list_head list; +/** + * prog_entry - a singe entry in the filter program + * @target: Index to jump to on a branch (actually one minus the index) + * @when_to_branch: The value of the result of the predicate to do a branch + * @pred: The predicate to execute. + */ +struct prog_entry { + int target; + int when_to_branch; + struct filter_pred *pred; }; -struct filter_parse_state { - struct filter_op *ops; - struct list_head opstack; - struct list_head postfix; +/** + * update_preds- assign a program entry a label target + * @prog: The program array + * @N: The index of the current entry in @prog + * @when_to_branch: What to assign a program entry for its branch condition + * + * The program entry at @N has a target that points to the index of a program + * entry that can have its target and when_to_branch fields updated. + * Update the current program entry denoted by index @N target field to be + * that of the updated entry. This will denote the entry to update if + * we are processing an "||" after an "&&" + */ +static void update_preds(struct prog_entry *prog, int N, int invert) +{ + int t, s; + + t = prog[N].target; + s = prog[t].target; + prog[t].when_to_branch = invert; + prog[t].target = N; + prog[N].target = s; +} + +struct filter_parse_error { int lasterr; int lasterr_pos; - - struct { - char *string; - unsigned int cnt; - unsigned int tail; - } infix; - - struct { - char string[MAX_FILTER_STR_VAL]; - int pos; - unsigned int tail; - } operand; }; -struct pred_stack { - struct filter_pred **preds; - int index; +static void parse_error(struct filter_parse_error *pe, int err, int pos) +{ + pe->lasterr = err; + pe->lasterr_pos = pos; +} + +typedef int (*parse_pred_fn)(const char *str, void *data, int pos, + struct filter_parse_error *pe, + struct filter_pred **pred); + +enum { + INVERT = 1, + PROCESS_AND = 2, + PROCESS_OR = 4, }; -/* If not of not match is equal to not of not, then it is a match */ +/* + * Without going into a formal proof, this explains the method that is used in + * parsing the logical expressions. + * + * For example, if we have: "a && !(!b || (c && g)) || d || e && !f" + * The first pass will convert it into the following program: + * + * n1: r=a; l1: if (!r) goto l4; + * n2: r=b; l2: if (!r) goto l4; + * n3: r=c; r=!r; l3: if (r) goto l4; + * n4: r=g; r=!r; l4: if (r) goto l5; + * n5: r=d; l5: if (r) goto T + * n6: r=e; l6: if (!r) goto l7; + * n7: r=f; r=!r; l7: if (!r) goto F + * T: return TRUE + * F: return FALSE + * + * To do this, we use a data structure to represent each of the above + * predicate and conditions that has: + * + * predicate, when_to_branch, invert, target + * + * The "predicate" will hold the function to determine the result "r". + * The "when_to_branch" denotes what "r" should be if a branch is to be taken + * "&&" would contain "!r" or (0) and "||" would contain "r" or (1). + * The "invert" holds whether the value should be reversed before testing. + * The "target" contains the label "l#" to jump to. + * + * A stack is created to hold values when parentheses are used. + * + * To simplify the logic, the labels will start at 0 and not 1. + * + * The possible invert values are 1 and 0. The number of "!"s that are in scope + * before the predicate determines the invert value, if the number is odd then + * the invert value is 1 and 0 otherwise. This means the invert value only + * needs to be toggled when a new "!" is introduced compared to what is stored + * on the stack, where parentheses were used. + * + * The top of the stack and "invert" are initialized to zero. + * + * ** FIRST PASS ** + * + * #1 A loop through all the tokens is done: + * + * #2 If the token is an "(", the stack is push, and the current stack value + * gets the current invert value, and the loop continues to the next token. + * The top of the stack saves the "invert" value to keep track of what + * the current inversion is. As "!(a && !b || c)" would require all + * predicates being affected separately by the "!" before the parentheses. + * And that would end up being equivalent to "(!a || b) && !c" + * + * #3 If the token is an "!", the current "invert" value gets inverted, and + * the loop continues. Note, if the next token is a predicate, then + * this "invert" value is only valid for the current program entry, + * and does not affect other predicates later on. + * + * The only other acceptable token is the predicate string. + * + * #4 A new entry into the program is added saving: the predicate and the + * current value of "invert". The target is currently assigned to the + * previous program index (this will not be its final value). + * + * #5 We now enter another loop and look at the next token. The only valid + * tokens are ")", "&&", "||" or end of the input string "\0". + * + * #6 The invert variable is reset to the current value saved on the top of + * the stack. + * + * #7 The top of the stack holds not only the current invert value, but also + * if a "&&" or "||" needs to be processed. Note, the "&&" takes higher + * precedence than "||". That is "a && b || c && d" is equivalent to + * "(a && b) || (c && d)". Thus the first thing to do is to see if "&&" needs + * to be processed. This is the case if an "&&" was the last token. If it was + * then we call update_preds(). This takes the program, the current index in + * the program, and the current value of "invert". More will be described + * below about this function. + * + * #8 If the next token is "&&" then we set a flag in the top of the stack + * that denotes that "&&" needs to be processed, break out of this loop + * and continue with the outer loop. + * + * #9 Otherwise, if a "||" needs to be processed then update_preds() is called. + * This is called with the program, the current index in the program, but + * this time with an inverted value of "invert" (that is !invert). This is + * because the value taken will become the "when_to_branch" value of the + * program. + * Note, this is called when the next token is not an "&&". As stated before, + * "&&" takes higher precedence, and "||" should not be processed yet if the + * next logical operation is "&&". + * + * #10 If the next token is "||" then we set a flag in the top of the stack + * that denotes that "||" needs to be processed, break out of this loop + * and continue with the outer loop. + * + * #11 If this is the end of the input string "\0" then we break out of both + * loops. + * + * #12 Otherwise, the next token is ")", where we pop the stack and continue + * this inner loop. + * + * Now to discuss the update_pred() function, as that is key to the setting up + * of the program. Remember the "target" of the program is initialized to the + * previous index and not the "l" label. The target holds the index into the + * program that gets affected by the operand. Thus if we have something like + * "a || b && c", when we process "a" the target will be "-1" (undefined). + * When we process "b", its target is "0", which is the index of "a", as that's + * the predicate that is affected by "||". But because the next token after "b" + * is "&&" we don't call update_preds(). Instead continue to "c". As the + * next token after "c" is not "&&" but the end of input, we first process the + * "&&" by calling update_preds() for the "&&" then we process the "||" by + * callin updates_preds() with the values for processing "||". + * + * What does that mean? What update_preds() does is to first save the "target" + * of the program entry indexed by the current program entry's "target" + * (remember the "target" is initialized to previous program entry), and then + * sets that "target" to the current index which represents the label "l#". + * That entry's "when_to_branch" is set to the value passed in (the "invert" + * or "!invert"). Then it sets the current program entry's target to the saved + * "target" value (the old value of the program that had its "target" updated + * to the label). + * + * Looking back at "a || b && c", we have the following steps: + * "a" - prog[0] = { "a", X, -1 } // pred, when_to_branch, target + * "||" - flag that we need to process "||"; continue outer loop + * "b" - prog[1] = { "b", X, 0 } + * "&&" - flag that we need to process "&&"; continue outer loop + * (Notice we did not process "||") + * "c" - prog[2] = { "c", X, 1 } + * update_preds(prog, 2, 0); // invert = 0 as we are processing "&&" + * t = prog[2].target; // t = 1 + * s = prog[t].target; // s = 0 + * prog[t].target = 2; // Set target to "l2" + * prog[t].when_to_branch = 0; + * prog[2].target = s; + * update_preds(prog, 2, 1); // invert = 1 as we are now processing "||" + * t = prog[2].target; // t = 0 + * s = prog[t].target; // s = -1 + * prog[t].target = 2; // Set target to "l2" + * prog[t].when_to_branch = 1; + * prog[2].target = s; + * + * #13 Which brings us to the final step of the first pass, which is to set + * the last program entry's when_to_branch and target, which will be + * when_to_branch = 0; target = N; ( the label after the program entry after + * the last program entry processed above). + * + * If we denote "TRUE" to be the entry after the last program entry processed, + * and "FALSE" the program entry after that, we are now done with the first + * pass. + * + * Making the above "a || b && c" have a progam of: + * prog[0] = { "a", 1, 2 } + * prog[1] = { "b", 0, 2 } + * prog[2] = { "c", 0, 3 } + * + * Which translates into: + * n0: r = a; l0: if (r) goto l2; + * n1: r = b; l1: if (!r) goto l2; + * n2: r = c; l2: if (!r) goto l3; // Which is the same as "goto F;" + * T: return TRUE; l3: + * F: return FALSE + * + * Although, after the first pass, the program is correct, it is + * inefficient. The simple sample of "a || b && c" could be easily been + * converted into: + * n0: r = a; if (r) goto T + * n1: r = b; if (!r) goto F + * n2: r = c; if (!r) goto F + * T: return TRUE; + * F: return FALSE; + * + * The First Pass is over the input string. The next too passes are over + * the program itself. + * + * ** SECOND PASS ** + * + * Which brings us to the second pass. If a jump to a label has the + * same condition as that label, it can instead jump to its target. + * The original example of "a && !(!b || (c && g)) || d || e && !f" + * where the first pass gives us: + * + * n1: r=a; l1: if (!r) goto l4; + * n2: r=b; l2: if (!r) goto l4; + * n3: r=c; r=!r; l3: if (r) goto l4; + * n4: r=g; r=!r; l4: if (r) goto l5; + * n5: r=d; l5: if (r) goto T + * n6: r=e; l6: if (!r) goto l7; + * n7: r=f; r=!r; l7: if (!r) goto F: + * T: return TRUE; + * F: return FALSE + * + * We can see that "l3: if (r) goto l4;" and at l4, we have "if (r) goto l5;". + * And "l5: if (r) goto T", we could optimize this by converting l3 and l4 + * to go directly to T. To accomplish this, we start from the last + * entry in the program and work our way back. If the target of the entry + * has the same "when_to_branch" then we could use that entry's target. + * Doing this, the above would end up as: + * + * n1: r=a; l1: if (!r) goto l4; + * n2: r=b; l2: if (!r) goto l4; + * n3: r=c; r=!r; l3: if (r) goto T; + * n4: r=g; r=!r; l4: if (r) goto T; + * n5: r=d; l5: if (r) goto T; + * n6: r=e; l6: if (!r) goto F; + * n7: r=f; r=!r; l7: if (!r) goto F; + * T: return TRUE + * F: return FALSE + * + * In that same pass, if the "when_to_branch" doesn't match, we can simply + * go to the program entry after the label. That is, "l2: if (!r) goto l4;" + * where "l4: if (r) goto T;", then we can convert l2 to be: + * "l2: if (!r) goto n5;". + * + * This will have the second pass give us: + * n1: r=a; l1: if (!r) goto n5; + * n2: r=b; l2: if (!r) goto n5; + * n3: r=c; r=!r; l3: if (r) goto T; + * n4: r=g; r=!r; l4: if (r) goto T; + * n5: r=d; l5: if (r) goto T + * n6: r=e; l6: if (!r) goto F; + * n7: r=f; r=!r; l7: if (!r) goto F + * T: return TRUE + * F: return FALSE + * + * Notice, all the "l#" labels are no longer used, and they can now + * be discarded. + * + * ** THIRD PASS ** + * + * For the third pass we deal with the inverts. As they simply just + * make the "when_to_branch" get inverted, a simple loop over the + * program to that does: "when_to_branch ^= invert;" will do the + * job, leaving us with: + * n1: r=a; if (!r) goto n5; + * n2: r=b; if (!r) goto n5; + * n3: r=c: if (!r) goto T; + * n4: r=g; if (!r) goto T; + * n5: r=d; if (r) goto T + * n6: r=e; if (!r) goto F; + * n7: r=f; if (r) goto F + * T: return TRUE + * F: return FALSE + * + * As "r = a; if (!r) goto n5;" is obviously the same as + * "if (!a) goto n5;" without doing anything we can interperate the + * program as: + * n1: if (!a) goto n5; + * n2: if (!b) goto n5; + * n3: if (!c) goto T; + * n4: if (!g) goto T; + * n5: if (d) goto T + * n6: if (!e) goto F; + * n7: if (f) goto F + * T: return TRUE + * F: return FALSE + * + * Since the inverts are discarded at the end, there's no reason to store + * them in the program array (and waste memory). A separate array to hold + * the inverts is used and freed at the end. + */ +static struct prog_entry * +predicate_parse(const char *str, int nr_parens, int nr_preds, + parse_pred_fn parse_pred, void *data, + struct filter_parse_error *pe) +{ + struct prog_entry *prog_stack; + struct prog_entry *prog; + const char *ptr = str; + char *inverts = NULL; + int *op_stack; + int *top; + int invert = 0; + int ret = -ENOMEM; + int len; + int N = 0; + int i; + + nr_preds += 2; /* For TRUE and FALSE */ + + op_stack = kmalloc(sizeof(*op_stack) * nr_parens, GFP_KERNEL); + if (!op_stack) + return ERR_PTR(-ENOMEM); + prog_stack = kmalloc(sizeof(*prog_stack) * nr_preds, GFP_KERNEL); + if (!prog_stack) { + parse_error(pe, -ENOMEM, 0); + goto out_free; + } + inverts = kmalloc(sizeof(*inverts) * nr_preds, GFP_KERNEL); + if (!inverts) { + parse_error(pe, -ENOMEM, 0); + goto out_free; + } + + top = op_stack; + prog = prog_stack; + *top = 0; + + /* First pass */ + while (*ptr) { /* #1 */ + const char *next = ptr++; + + if (isspace(*next)) + continue; + + switch (*next) { + case '(': /* #2 */ + if (top - op_stack > nr_parens) + return ERR_PTR(-EINVAL); + *(++top) = invert; + continue; + case '!': /* #3 */ + if (!is_not(next)) + break; + invert = !invert; + continue; + } + + if (N >= nr_preds) { + parse_error(pe, FILT_ERR_TOO_MANY_PREDS, next - str); + goto out_free; + } + + inverts[N] = invert; /* #4 */ + prog[N].target = N-1; + + len = parse_pred(next, data, ptr - str, pe, &prog[N].pred); + if (len < 0) { + ret = len; + goto out_free; + } + ptr = next + len; + + N++; + + ret = -1; + while (1) { /* #5 */ + next = ptr++; + if (isspace(*next)) + continue; + + switch (*next) { + case ')': + case '\0': + break; + case '&': + case '|': + if (next[1] == next[0]) { + ptr++; + break; + } + default: + parse_error(pe, FILT_ERR_TOO_MANY_PREDS, + next - str); + goto out_free; + } + + invert = *top & INVERT; + + if (*top & PROCESS_AND) { /* #7 */ + update_preds(prog, N - 1, invert); + *top &= ~PROCESS_AND; + } + if (*next == '&') { /* #8 */ + *top |= PROCESS_AND; + break; + } + if (*top & PROCESS_OR) { /* #9 */ + update_preds(prog, N - 1, !invert); + *top &= ~PROCESS_OR; + } + if (*next == '|') { /* #10 */ + *top |= PROCESS_OR; + break; + } + if (!*next) /* #11 */ + goto out; + + if (top == op_stack) { + ret = -1; + /* Too few '(' */ + parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, ptr - str); + goto out_free; + } + top--; /* #12 */ + } + } + out: + if (top != op_stack) { + /* Too many '(' */ + parse_error(pe, FILT_ERR_TOO_MANY_OPEN, ptr - str); + goto out_free; + } + + prog[N].pred = NULL; /* #13 */ + prog[N].target = 1; /* TRUE */ + prog[N+1].pred = NULL; + prog[N+1].target = 0; /* FALSE */ + prog[N-1].target = N; + prog[N-1].when_to_branch = false; + + /* Second Pass */ + for (i = N-1 ; i--; ) { + int target = prog[i].target; + if (prog[i].when_to_branch == prog[target].when_to_branch) + prog[i].target = prog[target].target; + } + + /* Third Pass */ + for (i = 0; i < N; i++) { + invert = inverts[i] ^ prog[i].when_to_branch; + prog[i].when_to_branch = invert; + /* Make sure the program always moves forward */ + if (WARN_ON(prog[i].target <= i)) { + ret = -EINVAL; + goto out_free; + } + } + + return prog; +out_free: + kfree(op_stack); + kfree(prog_stack); + kfree(inverts); + return ERR_PTR(ret); +} + #define DEFINE_COMPARISON_PRED(type) \ static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = (*addr < val); \ - return !!match == !pred->not; \ + return *addr < val; \ } \ static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = (*addr <= val); \ - return !!match == !pred->not; \ + return *addr <= val; \ } \ static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = (*addr > val); \ - return !!match == !pred->not; \ + return *addr > val; \ } \ static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = (*addr >= val); \ - return !!match == !pred->not; \ + return *addr >= val; \ } \ static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = !!(*addr & val); \ - return match == !pred->not; \ + return !!(*addr & val); \ } \ static const filter_pred_fn_t pred_funcs_##type[] = { \ - filter_pred_LT_##type, \ filter_pred_LE_##type, \ - filter_pred_GT_##type, \ + filter_pred_LT_##type, \ filter_pred_GE_##type, \ + filter_pred_GT_##type, \ filter_pred_BAND_##type, \ }; -#define PRED_FUNC_START OP_LT - #define DEFINE_EQUALITY_PRED(size) \ static int filter_pred_##size(struct filter_pred *pred, void *event) \ { \ @@ -272,44 +704,36 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event) static int filter_pred_cpu(struct filter_pred *pred, void *event) { int cpu, cmp; - int match = 0; cpu = raw_smp_processor_id(); cmp = pred->val; switch (pred->op) { case OP_EQ: - match = cpu == cmp; - break; + return cpu == cmp; + case OP_NE: + return cpu != cmp; case OP_LT: - match = cpu < cmp; - break; + return cpu < cmp; case OP_LE: - match = cpu <= cmp; - break; + return cpu <= cmp; case OP_GT: - match = cpu > cmp; - break; + return cpu > cmp; case OP_GE: - match = cpu >= cmp; - break; + return cpu >= cmp; default: - break; + return 0; } - - return !!match == !pred->not; } /* Filter predicate for COMM. */ static int filter_pred_comm(struct filter_pred *pred, void *event) { - int cmp, match; + int cmp; cmp = pred->regex.match(current->comm, &pred->regex, - pred->regex.field_len); - match = cmp ^ pred->not; - - return match; + TASK_COMM_LEN); + return cmp ^ pred->not; } static int filter_pred_none(struct filter_pred *pred, void *event) @@ -366,6 +790,7 @@ static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused) return 1; return 0; } + /** * filter_parse_regex - parse a basic regex * @buff: the raw regex @@ -426,10 +851,9 @@ static void filter_build_regex(struct filter_pred *pred) struct regex *r = &pred->regex; char *search; enum regex_type type = MATCH_FULL; - int not = 0; if (pred->op == OP_GLOB) { - type = filter_parse_regex(r->pattern, r->len, &search, ¬); + type = filter_parse_regex(r->pattern, r->len, &search, &pred->not); r->len = strlen(search); memmove(r->pattern, search, r->len+1); } @@ -451,210 +875,32 @@ static void filter_build_regex(struct filter_pred *pred) r->match = regex_match_glob; break; } - - pred->not ^= not; -} - -enum move_type { - MOVE_DOWN, - MOVE_UP_FROM_LEFT, - MOVE_UP_FROM_RIGHT -}; - -static struct filter_pred * -get_pred_parent(struct filter_pred *pred, struct filter_pred *preds, - int index, enum move_type *move) -{ - if (pred->parent & FILTER_PRED_IS_RIGHT) - *move = MOVE_UP_FROM_RIGHT; - else - *move = MOVE_UP_FROM_LEFT; - pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT]; - - return pred; -} - -enum walk_return { - WALK_PRED_ABORT, - WALK_PRED_PARENT, - WALK_PRED_DEFAULT, -}; - -typedef int (*filter_pred_walkcb_t) (enum move_type move, - struct filter_pred *pred, - int *err, void *data); - -static int walk_pred_tree(struct filter_pred *preds, - struct filter_pred *root, - filter_pred_walkcb_t cb, void *data) -{ - struct filter_pred *pred = root; - enum move_type move = MOVE_DOWN; - int done = 0; - - if (!preds) - return -EINVAL; - - do { - int err = 0, ret; - - ret = cb(move, pred, &err, data); - if (ret == WALK_PRED_ABORT) - return err; - if (ret == WALK_PRED_PARENT) - goto get_parent; - - switch (move) { - case MOVE_DOWN: - if (pred->left != FILTER_PRED_INVALID) { - pred = &preds[pred->left]; - continue; - } - goto get_parent; - case MOVE_UP_FROM_LEFT: - pred = &preds[pred->right]; - move = MOVE_DOWN; - continue; - case MOVE_UP_FROM_RIGHT: - get_parent: - if (pred == root) - break; - pred = get_pred_parent(pred, preds, - pred->parent, - &move); - continue; - } - done = 1; - } while (!done); - - /* We are fine. */ - return 0; -} - -/* - * A series of AND or ORs where found together. Instead of - * climbing up and down the tree branches, an array of the - * ops were made in order of checks. We can just move across - * the array and short circuit if needed. - */ -static int process_ops(struct filter_pred *preds, - struct filter_pred *op, void *rec) -{ - struct filter_pred *pred; - int match = 0; - int type; - int i; - - /* - * Micro-optimization: We set type to true if op - * is an OR and false otherwise (AND). Then we - * just need to test if the match is equal to - * the type, and if it is, we can short circuit the - * rest of the checks: - * - * if ((match && op->op == OP_OR) || - * (!match && op->op == OP_AND)) - * return match; - */ - type = op->op == OP_OR; - - for (i = 0; i < op->val; i++) { - pred = &preds[op->ops[i]]; - if (!WARN_ON_ONCE(!pred->fn)) - match = pred->fn(pred, rec); - if (!!match == type) - break; - } - /* If not of not match is equal to not of not, then it is a match */ - return !!match == !op->not; -} - -struct filter_match_preds_data { - struct filter_pred *preds; - int match; - void *rec; -}; - -static int filter_match_preds_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) -{ - struct filter_match_preds_data *d = data; - - *err = 0; - switch (move) { - case MOVE_DOWN: - /* only AND and OR have children */ - if (pred->left != FILTER_PRED_INVALID) { - /* If ops is set, then it was folded. */ - if (!pred->ops) - return WALK_PRED_DEFAULT; - /* We can treat folded ops as a leaf node */ - d->match = process_ops(d->preds, pred, d->rec); - } else { - if (!WARN_ON_ONCE(!pred->fn)) - d->match = pred->fn(pred, d->rec); - } - - return WALK_PRED_PARENT; - case MOVE_UP_FROM_LEFT: - /* - * Check for short circuits. - * - * Optimization: !!match == (pred->op == OP_OR) - * is the same as: - * if ((match && pred->op == OP_OR) || - * (!match && pred->op == OP_AND)) - */ - if (!!d->match == (pred->op == OP_OR)) - return WALK_PRED_PARENT; - break; - case MOVE_UP_FROM_RIGHT: - break; - } - - return WALK_PRED_DEFAULT; } /* return 1 if event matches, 0 otherwise (discard) */ int filter_match_preds(struct event_filter *filter, void *rec) { - struct filter_pred *preds; - struct filter_pred *root; - struct filter_match_preds_data data = { - /* match is currently meaningless */ - .match = -1, - .rec = rec, - }; - int n_preds, ret; + struct prog_entry *prog; + int i; /* no filter is considered a match */ if (!filter) return 1; - n_preds = filter->n_preds; - if (!n_preds) + prog = rcu_dereference_sched(filter->prog); + if (!prog) return 1; - /* - * n_preds, root and filter->preds are protect with preemption disabled. - */ - root = rcu_dereference_sched(filter->root); - if (!root) - return 1; - - data.preds = preds = rcu_dereference_sched(filter->preds); - ret = walk_pred_tree(preds, root, filter_match_preds_cb, &data); - WARN_ON(ret); - return data.match; + for (i = 0; prog[i].pred; i++) { + struct filter_pred *pred = prog[i].pred; + int match = pred->fn(pred, rec); + if (match == prog[i].when_to_branch) + i = prog[i].target; + } + return prog[i].target; } EXPORT_SYMBOL_GPL(filter_match_preds); -static void parse_error(struct filter_parse_state *ps, int err, int pos) -{ - ps->lasterr = err; - ps->lasterr_pos = pos; -} - static void remove_filter_string(struct event_filter *filter) { if (!filter) @@ -664,57 +910,44 @@ static void remove_filter_string(struct event_filter *filter) filter->filter_string = NULL; } -static int replace_filter_string(struct event_filter *filter, - char *filter_string) -{ - kfree(filter->filter_string); - filter->filter_string = kstrdup(filter_string, GFP_KERNEL); - if (!filter->filter_string) - return -ENOMEM; - - return 0; -} - -static int append_filter_string(struct event_filter *filter, - char *string) -{ - int newlen; - char *new_filter_string; - - BUG_ON(!filter->filter_string); - newlen = strlen(filter->filter_string) + strlen(string) + 1; - new_filter_string = kmalloc(newlen, GFP_KERNEL); - if (!new_filter_string) - return -ENOMEM; - - strcpy(new_filter_string, filter->filter_string); - strcat(new_filter_string, string); - kfree(filter->filter_string); - filter->filter_string = new_filter_string; - - return 0; -} - -static void append_filter_err(struct filter_parse_state *ps, +static void append_filter_err(struct filter_parse_error *pe, struct event_filter *filter) { - int pos = ps->lasterr_pos; - char *buf, *pbuf; + struct trace_seq *s; + int pos = pe->lasterr_pos; + char *buf; + int len; + + if (WARN_ON(!filter->filter_string)) + return; - buf = (char *)__get_free_page(GFP_KERNEL); - if (!buf) + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) return; + trace_seq_init(s); - append_filter_string(filter, "\n"); - memset(buf, ' ', PAGE_SIZE); - if (pos > PAGE_SIZE - 128) - pos = 0; - buf[pos] = '^'; - pbuf = &buf[pos] + 1; + len = strlen(filter->filter_string); + if (pos > len) + pos = len; - sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]); - append_filter_string(filter, buf); - free_page((unsigned long) buf); + /* indexing is off by one */ + if (pos) + pos++; + + trace_seq_puts(s, filter->filter_string); + if (pe->lasterr > 0) { + trace_seq_printf(s, "\n%*s", pos, "^"); + trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]); + } else { + trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr); + } + trace_seq_putc(s, 0); + buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL); + if (buf) { + kfree(filter->filter_string); + filter->filter_string = buf; + } + kfree(s); } static inline struct event_filter *event_filter(struct trace_event_file *file) @@ -747,108 +980,18 @@ void print_subsystem_event_filter(struct event_subsystem *system, mutex_unlock(&event_mutex); } -static int __alloc_pred_stack(struct pred_stack *stack, int n_preds) -{ - stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL); - if (!stack->preds) - return -ENOMEM; - stack->index = n_preds; - return 0; -} - -static void __free_pred_stack(struct pred_stack *stack) -{ - kfree(stack->preds); - stack->index = 0; -} - -static int __push_pred_stack(struct pred_stack *stack, - struct filter_pred *pred) -{ - int index = stack->index; - - if (WARN_ON(index == 0)) - return -ENOSPC; - - stack->preds[--index] = pred; - stack->index = index; - return 0; -} - -static struct filter_pred * -__pop_pred_stack(struct pred_stack *stack) -{ - struct filter_pred *pred; - int index = stack->index; - - pred = stack->preds[index++]; - if (!pred) - return NULL; - - stack->index = index; - return pred; -} - -static int filter_set_pred(struct event_filter *filter, - int idx, - struct pred_stack *stack, - struct filter_pred *src) -{ - struct filter_pred *dest = &filter->preds[idx]; - struct filter_pred *left; - struct filter_pred *right; - - *dest = *src; - dest->index = idx; - - if (dest->op == OP_OR || dest->op == OP_AND) { - right = __pop_pred_stack(stack); - left = __pop_pred_stack(stack); - if (!left || !right) - return -EINVAL; - /* - * If both children can be folded - * and they are the same op as this op or a leaf, - * then this op can be folded. - */ - if (left->index & FILTER_PRED_FOLD && - ((left->op == dest->op && !left->not) || - left->left == FILTER_PRED_INVALID) && - right->index & FILTER_PRED_FOLD && - ((right->op == dest->op && !right->not) || - right->left == FILTER_PRED_INVALID)) - dest->index |= FILTER_PRED_FOLD; - - dest->left = left->index & ~FILTER_PRED_FOLD; - dest->right = right->index & ~FILTER_PRED_FOLD; - left->parent = dest->index & ~FILTER_PRED_FOLD; - right->parent = dest->index | FILTER_PRED_IS_RIGHT; - } else { - /* - * Make dest->left invalid to be used as a quick - * way to know this is a leaf node. - */ - dest->left = FILTER_PRED_INVALID; - - /* All leafs allow folding the parent ops. */ - dest->index |= FILTER_PRED_FOLD; - } - - return __push_pred_stack(stack, dest); -} - -static void __free_preds(struct event_filter *filter) +static void free_prog(struct event_filter *filter) { + struct prog_entry *prog; int i; - if (filter->preds) { - for (i = 0; i < filter->n_preds; i++) - kfree(filter->preds[i].ops); - kfree(filter->preds); - filter->preds = NULL; - } - filter->a_preds = 0; - filter->n_preds = 0; + prog = rcu_access_pointer(filter->prog); + if (!prog) + return; + + for (i = 0; prog[i].pred; i++) + kfree(prog[i].pred); + kfree(prog); } static void filter_disable(struct trace_event_file *file) @@ -866,7 +1009,7 @@ static void __free_filter(struct event_filter *filter) if (!filter) return; - __free_preds(filter); + free_prog(filter); kfree(filter->filter_string); kfree(filter); } @@ -876,38 +1019,6 @@ void free_event_filter(struct event_filter *filter) __free_filter(filter); } -static struct event_filter *__alloc_filter(void) -{ - struct event_filter *filter; - - filter = kzalloc(sizeof(*filter), GFP_KERNEL); - return filter; -} - -static int __alloc_preds(struct event_filter *filter, int n_preds) -{ - struct filter_pred *pred; - int i; - - if (filter->preds) - __free_preds(filter); - - filter->preds = kcalloc(n_preds, sizeof(*filter->preds), GFP_KERNEL); - - if (!filter->preds) - return -ENOMEM; - - filter->a_preds = n_preds; - filter->n_preds = 0; - - for (i = 0; i < n_preds; i++) { - pred = &filter->preds[i]; - pred->fn = filter_pred_none; - } - - return 0; -} - static inline void __remove_filter(struct trace_event_file *file) { filter_disable(file); @@ -944,27 +1055,6 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, } } -static int filter_add_pred(struct filter_parse_state *ps, - struct event_filter *filter, - struct filter_pred *pred, - struct pred_stack *stack) -{ - int err; - - if (WARN_ON(filter->n_preds == filter->a_preds)) { - parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); - return -ENOSPC; - } - - err = filter_set_pred(filter, filter->n_preds, stack, pred); - if (err) - return err; - - filter->n_preds++; - - return 0; -} - int filter_assign_type(const char *type) { if (strstr(type, "__data_loc") && strstr(type, "char")) @@ -976,761 +1066,449 @@ int filter_assign_type(const char *type) return FILTER_OTHER; } -static bool is_legal_op(struct ftrace_event_field *field, enum filter_op_ids op) -{ - if (is_string_field(field) && - (op != OP_EQ && op != OP_NE && op != OP_GLOB)) - return false; - if (!is_string_field(field) && op == OP_GLOB) - return false; - - return true; -} - static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op, int field_size, int field_is_signed) { filter_pred_fn_t fn = NULL; + int pred_func_index = -1; + + switch (op) { + case OP_EQ: + case OP_NE: + break; + default: + if (WARN_ON_ONCE(op < PRED_FUNC_START)) + return NULL; + pred_func_index = op - PRED_FUNC_START; + if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX)) + return NULL; + } switch (field_size) { case 8: - if (op == OP_EQ || op == OP_NE) + if (pred_func_index < 0) fn = filter_pred_64; else if (field_is_signed) - fn = pred_funcs_s64[op - PRED_FUNC_START]; + fn = pred_funcs_s64[pred_func_index]; else - fn = pred_funcs_u64[op - PRED_FUNC_START]; + fn = pred_funcs_u64[pred_func_index]; break; case 4: - if (op == OP_EQ || op == OP_NE) + if (pred_func_index < 0) fn = filter_pred_32; else if (field_is_signed) - fn = pred_funcs_s32[op - PRED_FUNC_START]; + fn = pred_funcs_s32[pred_func_index]; else - fn = pred_funcs_u32[op - PRED_FUNC_START]; + fn = pred_funcs_u32[pred_func_index]; break; case 2: - if (op == OP_EQ || op == OP_NE) + if (pred_func_index < 0) fn = filter_pred_16; else if (field_is_signed) - fn = pred_funcs_s16[op - PRED_FUNC_START]; + fn = pred_funcs_s16[pred_func_index]; else - fn = pred_funcs_u16[op - PRED_FUNC_START]; + fn = pred_funcs_u16[pred_func_index]; break; case 1: - if (op == OP_EQ || op == OP_NE) + if (pred_func_index < 0) fn = filter_pred_8; else if (field_is_signed) - fn = pred_funcs_s8[op - PRED_FUNC_START]; + fn = pred_funcs_s8[pred_func_index]; else - fn = pred_funcs_u8[op - PRED_FUNC_START]; + fn = pred_funcs_u8[pred_func_index]; break; } return fn; } -static int init_pred(struct filter_parse_state *ps, - struct ftrace_event_field *field, - struct filter_pred *pred) - +/* Called when a predicate is encountered by predicate_parse() */ +static int parse_pred(const char *str, void *data, + int pos, struct filter_parse_error *pe, + struct filter_pred **pred_ptr) { - filter_pred_fn_t fn = filter_pred_none; - unsigned long long val; + struct trace_event_call *call = data; + struct ftrace_event_field *field; + struct filter_pred *pred = NULL; + char num_buf[24]; /* Big enough to hold an address */ + char *field_name; + char q; + u64 val; + int len; int ret; + int op; + int s; + int i = 0; - pred->offset = field->offset; - - if (!is_legal_op(field, pred->op)) { - parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0); - return -EINVAL; - } - - if (field->filter_type == FILTER_COMM) { - filter_build_regex(pred); - fn = filter_pred_comm; - pred->regex.field_len = TASK_COMM_LEN; - } else if (is_string_field(field)) { - filter_build_regex(pred); - - if (field->filter_type == FILTER_STATIC_STRING) { - fn = filter_pred_string; - pred->regex.field_len = field->size; - } else if (field->filter_type == FILTER_DYN_STRING) - fn = filter_pred_strloc; - else - fn = filter_pred_pchar; - } else if (is_function_field(field)) { - if (strcmp(field->name, "ip")) { - parse_error(ps, FILT_ERR_IP_FIELD_ONLY, 0); - return -EINVAL; - } - } else { - if (field->is_signed) - ret = kstrtoll(pred->regex.pattern, 0, &val); - else - ret = kstrtoull(pred->regex.pattern, 0, &val); - if (ret) { - parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0); - return -EINVAL; - } - pred->val = val; - - if (field->filter_type == FILTER_CPU) - fn = filter_pred_cpu; - else - fn = select_comparison_fn(pred->op, field->size, - field->is_signed); - if (!fn) { - parse_error(ps, FILT_ERR_INVALID_OP, 0); - return -EINVAL; - } - } - - if (pred->op == OP_NE) - pred->not ^= 1; - - pred->fn = fn; - return 0; -} - -static void parse_init(struct filter_parse_state *ps, - struct filter_op *ops, - char *infix_string) -{ - memset(ps, '\0', sizeof(*ps)); - - ps->infix.string = infix_string; - ps->infix.cnt = strlen(infix_string); - ps->ops = ops; - - INIT_LIST_HEAD(&ps->opstack); - INIT_LIST_HEAD(&ps->postfix); -} - -static char infix_next(struct filter_parse_state *ps) -{ - if (!ps->infix.cnt) - return 0; - - ps->infix.cnt--; - - return ps->infix.string[ps->infix.tail++]; -} + /* First find the field to associate to */ + while (isspace(str[i])) + i++; + s = i; -static char infix_peek(struct filter_parse_state *ps) -{ - if (ps->infix.tail == strlen(ps->infix.string)) - return 0; + while (isalnum(str[i]) || str[i] == '_') + i++; - return ps->infix.string[ps->infix.tail]; -} + len = i - s; -static void infix_advance(struct filter_parse_state *ps) -{ - if (!ps->infix.cnt) - return; + if (!len) + return -1; - ps->infix.cnt--; - ps->infix.tail++; -} + field_name = kmemdup_nul(str + s, len, GFP_KERNEL); + if (!field_name) + return -ENOMEM; -static inline int is_precedence_lower(struct filter_parse_state *ps, - int a, int b) -{ - return ps->ops[a].precedence < ps->ops[b].precedence; -} + /* Make sure that the field exists */ -static inline int is_op_char(struct filter_parse_state *ps, char c) -{ - int i; - - for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { - if (ps->ops[i].string[0] == c) - return 1; + field = trace_find_event_field(call, field_name); + kfree(field_name); + if (!field) { + parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i); + return -EINVAL; } - return 0; -} + while (isspace(str[i])) + i++; -static int infix_get_op(struct filter_parse_state *ps, char firstc) -{ - char nextc = infix_peek(ps); - char opstr[3]; - int i; - - opstr[0] = firstc; - opstr[1] = nextc; - opstr[2] = '\0'; - - for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { - if (!strcmp(opstr, ps->ops[i].string)) { - infix_advance(ps); - return ps->ops[i].id; - } + /* Make sure this op is supported */ + for (op = 0; ops[op]; op++) { + /* This is why '<=' must come before '<' in ops[] */ + if (strncmp(str + i, ops[op], strlen(ops[op])) == 0) + break; } - opstr[1] = '\0'; - - for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) { - if (!strcmp(opstr, ps->ops[i].string)) - return ps->ops[i].id; + if (!ops[op]) { + parse_error(pe, FILT_ERR_INVALID_OP, pos + i); + goto err_free; } - return OP_NONE; -} - -static inline void clear_operand_string(struct filter_parse_state *ps) -{ - memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL); - ps->operand.tail = 0; -} - -static inline int append_operand_char(struct filter_parse_state *ps, char c) -{ - if (ps->operand.tail == MAX_FILTER_STR_VAL - 1) - return -EINVAL; - - ps->operand.string[ps->operand.tail++] = c; + i += strlen(ops[op]); - return 0; -} + while (isspace(str[i])) + i++; -static int filter_opstack_push(struct filter_parse_state *ps, - enum filter_op_ids op) -{ - struct opstack_op *opstack_op; + s = i; - opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL); - if (!opstack_op) + pred = kzalloc(sizeof(*pred), GFP_KERNEL); + if (!pred) return -ENOMEM; - opstack_op->op = op; - list_add(&opstack_op->list, &ps->opstack); + pred->field = field; + pred->offset = field->offset; + pred->op = op; - return 0; -} + if (ftrace_event_is_function(call)) { + /* + * Perf does things different with function events. + * It only allows an "ip" field, and expects a string. + * But the string does not need to be surrounded by quotes. + * If it is a string, the assigned function as a nop, + * (perf doesn't use it) and grab everything. + */ + if (strcmp(field->name, "ip") != 0) { + parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i); + goto err_free; + } + pred->fn = filter_pred_none; + + /* + * Quotes are not required, but if they exist then we need + * to read them till we hit a matching one. + */ + if (str[i] == '\'' || str[i] == '"') + q = str[i]; + else + q = 0; + + for (i++; str[i]; i++) { + if (q && str[i] == q) + break; + if (!q && (str[i] == ')' || str[i] == '&' || + str[i] == '|')) + break; + } + /* Skip quotes */ + if (q) + s++; + len = i - s; + if (len >= MAX_FILTER_STR_VAL) { + parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i); + goto err_free; + } -static int filter_opstack_empty(struct filter_parse_state *ps) -{ - return list_empty(&ps->opstack); -} + pred->regex.len = len; + strncpy(pred->regex.pattern, str + s, len); + pred->regex.pattern[len] = 0; + + /* This is either a string, or an integer */ + } else if (str[i] == '\'' || str[i] == '"') { + char q = str[i]; + + /* Make sure the op is OK for strings */ + switch (op) { + case OP_NE: + pred->not = 1; + /* Fall through */ + case OP_GLOB: + case OP_EQ: + break; + default: + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + goto err_free; + } -static int filter_opstack_top(struct filter_parse_state *ps) -{ - struct opstack_op *opstack_op; + /* Make sure the field is OK for strings */ + if (!is_string_field(field)) { + parse_error(pe, FILT_ERR_EXPECT_DIGIT, pos + i); + goto err_free; + } - if (filter_opstack_empty(ps)) - return OP_NONE; + for (i++; str[i]; i++) { + if (str[i] == q) + break; + } + if (!str[i]) { + parse_error(pe, FILT_ERR_MISSING_QUOTE, pos + i); + goto err_free; + } - opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); + /* Skip quotes */ + s++; + len = i - s; + if (len >= MAX_FILTER_STR_VAL) { + parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i); + goto err_free; + } - return opstack_op->op; -} + pred->regex.len = len; + strncpy(pred->regex.pattern, str + s, len); + pred->regex.pattern[len] = 0; -static int filter_opstack_pop(struct filter_parse_state *ps) -{ - struct opstack_op *opstack_op; - enum filter_op_ids op; + filter_build_regex(pred); - if (filter_opstack_empty(ps)) - return OP_NONE; + if (field->filter_type == FILTER_COMM) { + pred->fn = filter_pred_comm; - opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list); - op = opstack_op->op; - list_del(&opstack_op->list); + } else if (field->filter_type == FILTER_STATIC_STRING) { + pred->fn = filter_pred_string; + pred->regex.field_len = field->size; - kfree(opstack_op); + } else if (field->filter_type == FILTER_DYN_STRING) + pred->fn = filter_pred_strloc; + else + pred->fn = filter_pred_pchar; + /* go past the last quote */ + i++; - return op; -} + } else if (isdigit(str[i])) { -static void filter_opstack_clear(struct filter_parse_state *ps) -{ - while (!filter_opstack_empty(ps)) - filter_opstack_pop(ps); -} - -static char *curr_operand(struct filter_parse_state *ps) -{ - return ps->operand.string; -} + /* Make sure the field is not a string */ + if (is_string_field(field)) { + parse_error(pe, FILT_ERR_EXPECT_STRING, pos + i); + goto err_free; + } -static int postfix_append_operand(struct filter_parse_state *ps, char *operand) -{ - struct postfix_elt *elt; + if (op == OP_GLOB) { + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + goto err_free; + } - elt = kmalloc(sizeof(*elt), GFP_KERNEL); - if (!elt) - return -ENOMEM; + /* We allow 0xDEADBEEF */ + while (isalnum(str[i])) + i++; - elt->op = OP_NONE; - elt->operand = kstrdup(operand, GFP_KERNEL); - if (!elt->operand) { - kfree(elt); - return -ENOMEM; - } + len = i - s; + /* 0xfeedfacedeadbeef is 18 chars max */ + if (len >= sizeof(num_buf)) { + parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i); + goto err_free; + } - list_add_tail(&elt->list, &ps->postfix); + strncpy(num_buf, str + s, len); + num_buf[len] = 0; - return 0; -} + /* Make sure it is a value */ + if (field->is_signed) + ret = kstrtoll(num_buf, 0, &val); + else + ret = kstrtoull(num_buf, 0, &val); + if (ret) { + parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s); + goto err_free; + } -static int postfix_append_op(struct filter_parse_state *ps, enum filter_op_ids op) -{ - struct postfix_elt *elt; + pred->val = val; - elt = kmalloc(sizeof(*elt), GFP_KERNEL); - if (!elt) - return -ENOMEM; + if (field->filter_type == FILTER_CPU) + pred->fn = filter_pred_cpu; + else { + pred->fn = select_comparison_fn(pred->op, field->size, + field->is_signed); + if (pred->op == OP_NE) + pred->not = 1; + } - elt->op = op; - elt->operand = NULL; + } else { + parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i); + goto err_free; + } - list_add_tail(&elt->list, &ps->postfix); + *pred_ptr = pred; + return i; - return 0; +err_free: + kfree(pred); + return -EINVAL; } -static void postfix_clear(struct filter_parse_state *ps) -{ - struct postfix_elt *elt; +enum { + TOO_MANY_CLOSE = -1, + TOO_MANY_OPEN = -2, + MISSING_QUOTE = -3, +}; - while (!list_empty(&ps->postfix)) { - elt = list_first_entry(&ps->postfix, struct postfix_elt, list); - list_del(&elt->list); - kfree(elt->operand); - kfree(elt); - } -} +/* + * Read the filter string once to calculate the number of predicates + * as well as how deep the parentheses go. + * + * Returns: + * 0 - everything is fine (err is undefined) + * -1 - too many ')' + * -2 - too many '(' + * -3 - No matching quote + */ +static int calc_stack(const char *str, int *parens, int *preds, int *err) +{ + bool is_pred = false; + int nr_preds = 0; + int open = 1; /* Count the expression as "(E)" */ + int last_quote = 0; + int max_open = 1; + int quote = 0; + int i; -static int filter_parse(struct filter_parse_state *ps) -{ - enum filter_op_ids op, top_op; - int in_string = 0; - char ch; + *err = 0; - while ((ch = infix_next(ps))) { - if (ch == '"') { - in_string ^= 1; + for (i = 0; str[i]; i++) { + if (isspace(str[i])) continue; - } - - if (in_string) - goto parse_operand; - - if (isspace(ch)) + if (quote) { + if (str[i] == quote) + quote = 0; continue; + } - if (is_op_char(ps, ch)) { - op = infix_get_op(ps, ch); - if (op == OP_NONE) { - parse_error(ps, FILT_ERR_INVALID_OP, 0); - return -EINVAL; - } - - if (strlen(curr_operand(ps))) { - postfix_append_operand(ps, curr_operand(ps)); - clear_operand_string(ps); - } - - while (!filter_opstack_empty(ps)) { - top_op = filter_opstack_top(ps); - if (!is_precedence_lower(ps, top_op, op)) { - top_op = filter_opstack_pop(ps); - postfix_append_op(ps, top_op); - continue; - } + switch (str[i]) { + case '\'': + case '"': + quote = str[i]; + last_quote = i; + break; + case '|': + case '&': + if (str[i+1] != str[i]) break; - } - - filter_opstack_push(ps, op); + is_pred = false; continue; - } - - if (ch == '(') { - filter_opstack_push(ps, OP_OPEN_PAREN); + case '(': + is_pred = false; + open++; + if (open > max_open) + max_open = open; continue; - } - - if (ch == ')') { - if (strlen(curr_operand(ps))) { - postfix_append_operand(ps, curr_operand(ps)); - clear_operand_string(ps); - } - - top_op = filter_opstack_pop(ps); - while (top_op != OP_NONE) { - if (top_op == OP_OPEN_PAREN) - break; - postfix_append_op(ps, top_op); - top_op = filter_opstack_pop(ps); - } - if (top_op == OP_NONE) { - parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); - return -EINVAL; + case ')': + is_pred = false; + if (open == 1) { + *err = i; + return TOO_MANY_CLOSE; } + open--; continue; } -parse_operand: - if (append_operand_char(ps, ch)) { - parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0); - return -EINVAL; + if (!is_pred) { + nr_preds++; + is_pred = true; } } - if (strlen(curr_operand(ps))) - postfix_append_operand(ps, curr_operand(ps)); - - while (!filter_opstack_empty(ps)) { - top_op = filter_opstack_pop(ps); - if (top_op == OP_NONE) - break; - if (top_op == OP_OPEN_PAREN) { - parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0); - return -EINVAL; - } - postfix_append_op(ps, top_op); + if (quote) { + *err = last_quote; + return MISSING_QUOTE; } - return 0; -} - -static struct filter_pred *create_pred(struct filter_parse_state *ps, - struct trace_event_call *call, - enum filter_op_ids op, - char *operand1, char *operand2) -{ - struct ftrace_event_field *field; - static struct filter_pred pred; - - memset(&pred, 0, sizeof(pred)); - pred.op = op; - - if (op == OP_AND || op == OP_OR) - return &pred; - - if (!operand1 || !operand2) { - parse_error(ps, FILT_ERR_MISSING_FIELD, 0); - return NULL; - } - - field = trace_find_event_field(call, operand1); - if (!field) { - parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0); - return NULL; - } - - strcpy(pred.regex.pattern, operand2); - pred.regex.len = strlen(pred.regex.pattern); - pred.field = field; - return init_pred(ps, field, &pred) ? NULL : &pred; -} - -static int check_preds(struct filter_parse_state *ps) -{ - int n_normal_preds = 0, n_logical_preds = 0; - struct postfix_elt *elt; - int cnt = 0; - - list_for_each_entry(elt, &ps->postfix, list) { - if (elt->op == OP_NONE) { - cnt++; - continue; - } + if (open != 1) { + int level = open; - if (elt->op == OP_AND || elt->op == OP_OR) { - n_logical_preds++; - cnt--; - continue; + /* find the bad open */ + for (i--; i; i--) { + if (quote) { + if (str[i] == quote) + quote = 0; + continue; + } + switch (str[i]) { + case '(': + if (level == open) { + *err = i; + return TOO_MANY_OPEN; + } + level--; + break; + case ')': + level++; + break; + case '\'': + case '"': + quote = str[i]; + break; + } } - if (elt->op != OP_NOT) - cnt--; - n_normal_preds++; - /* all ops should have operands */ - if (cnt < 0) - break; - } - - if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) { - parse_error(ps, FILT_ERR_INVALID_FILTER, 0); - return -EINVAL; + /* First character is the '(' with missing ')' */ + *err = 0; + return TOO_MANY_OPEN; } + /* Set the size of the required stacks */ + *parens = max_open; + *preds = nr_preds; return 0; } -static int count_preds(struct filter_parse_state *ps) -{ - struct postfix_elt *elt; - int n_preds = 0; - - list_for_each_entry(elt, &ps->postfix, list) { - if (elt->op == OP_NONE) - continue; - n_preds++; - } - - return n_preds; -} - -struct check_pred_data { - int count; - int max; -}; - -static int check_pred_tree_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) -{ - struct check_pred_data *d = data; - - if (WARN_ON(d->count++ > d->max)) { - *err = -EINVAL; - return WALK_PRED_ABORT; - } - return WALK_PRED_DEFAULT; -} - -/* - * The tree is walked at filtering of an event. If the tree is not correctly - * built, it may cause an infinite loop. Check here that the tree does - * indeed terminate. - */ -static int check_pred_tree(struct event_filter *filter, - struct filter_pred *root) -{ - struct check_pred_data data = { - /* - * The max that we can hit a node is three times. - * Once going down, once coming up from left, and - * once coming up from right. This is more than enough - * since leafs are only hit a single time. - */ - .max = 3 * filter->n_preds, - .count = 0, - }; - - return walk_pred_tree(filter->preds, root, - check_pred_tree_cb, &data); -} - -static int count_leafs_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) -{ - int *count = data; - - if ((move == MOVE_DOWN) && - (pred->left == FILTER_PRED_INVALID)) - (*count)++; - - return WALK_PRED_DEFAULT; -} - -static int count_leafs(struct filter_pred *preds, struct filter_pred *root) -{ - int count = 0, ret; - - ret = walk_pred_tree(preds, root, count_leafs_cb, &count); - WARN_ON(ret); - return count; -} - -struct fold_pred_data { - struct filter_pred *root; - int count; - int children; -}; - -static int fold_pred_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) -{ - struct fold_pred_data *d = data; - struct filter_pred *root = d->root; - - if (move != MOVE_DOWN) - return WALK_PRED_DEFAULT; - if (pred->left != FILTER_PRED_INVALID) - return WALK_PRED_DEFAULT; - - if (WARN_ON(d->count == d->children)) { - *err = -EINVAL; - return WALK_PRED_ABORT; - } - - pred->index &= ~FILTER_PRED_FOLD; - root->ops[d->count++] = pred->index; - return WALK_PRED_DEFAULT; -} - -static int fold_pred(struct filter_pred *preds, struct filter_pred *root) -{ - struct fold_pred_data data = { - .root = root, - .count = 0, - }; - int children; - - /* No need to keep the fold flag */ - root->index &= ~FILTER_PRED_FOLD; - - /* If the root is a leaf then do nothing */ - if (root->left == FILTER_PRED_INVALID) - return 0; - - /* count the children */ - children = count_leafs(preds, &preds[root->left]); - children += count_leafs(preds, &preds[root->right]); - - root->ops = kcalloc(children, sizeof(*root->ops), GFP_KERNEL); - if (!root->ops) - return -ENOMEM; - - root->val = children; - data.children = children; - return walk_pred_tree(preds, root, fold_pred_cb, &data); -} - -static int fold_pred_tree_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) -{ - struct filter_pred *preds = data; - - if (move != MOVE_DOWN) - return WALK_PRED_DEFAULT; - if (!(pred->index & FILTER_PRED_FOLD)) - return WALK_PRED_DEFAULT; - - *err = fold_pred(preds, pred); - if (*err) - return WALK_PRED_ABORT; - - /* eveyrhing below is folded, continue with parent */ - return WALK_PRED_PARENT; -} - -/* - * To optimize the processing of the ops, if we have several "ors" or - * "ands" together, we can put them in an array and process them all - * together speeding up the filter logic. - */ -static int fold_pred_tree(struct event_filter *filter, - struct filter_pred *root) -{ - return walk_pred_tree(filter->preds, root, fold_pred_tree_cb, - filter->preds); -} - -static int replace_preds(struct trace_event_call *call, +static int process_preds(struct trace_event_call *call, + const char *filter_string, struct event_filter *filter, - struct filter_parse_state *ps, - bool dry_run) + struct filter_parse_error *pe) { - char *operand1 = NULL, *operand2 = NULL; - struct filter_pred *pred; - struct filter_pred *root; - struct postfix_elt *elt; - struct pred_stack stack = { }; /* init to NULL */ - int err; - int n_preds = 0; - - n_preds = count_preds(ps); - if (n_preds >= MAX_FILTER_PRED) { - parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); - return -ENOSPC; - } - - err = check_preds(ps); - if (err) - return err; - - if (!dry_run) { - err = __alloc_pred_stack(&stack, n_preds); - if (err) - return err; - err = __alloc_preds(filter, n_preds); - if (err) - goto fail; - } - - n_preds = 0; - list_for_each_entry(elt, &ps->postfix, list) { - if (elt->op == OP_NONE) { - if (!operand1) - operand1 = elt->operand; - else if (!operand2) - operand2 = elt->operand; - else { - parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0); - err = -EINVAL; - goto fail; - } - continue; - } - - if (elt->op == OP_NOT) { - if (!n_preds || operand1 || operand2) { - parse_error(ps, FILT_ERR_ILLEGAL_NOT_OP, 0); - err = -EINVAL; - goto fail; - } - if (!dry_run) - filter->preds[n_preds - 1].not ^= 1; - continue; - } - - if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) { - parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0); - err = -ENOSPC; - goto fail; - } - - pred = create_pred(ps, call, elt->op, operand1, operand2); - if (!pred) { - err = -EINVAL; - goto fail; - } + struct prog_entry *prog; + int nr_parens; + int nr_preds; + int index; + int ret; - if (!dry_run) { - err = filter_add_pred(ps, filter, pred, &stack); - if (err) - goto fail; + ret = calc_stack(filter_string, &nr_parens, &nr_preds, &index); + if (ret < 0) { + switch (ret) { + case MISSING_QUOTE: + parse_error(pe, FILT_ERR_MISSING_QUOTE, index); + break; + case TOO_MANY_OPEN: + parse_error(pe, FILT_ERR_TOO_MANY_OPEN, index); + break; + default: + parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, index); } - - operand1 = operand2 = NULL; + return ret; } - if (!dry_run) { - /* We should have one item left on the stack */ - pred = __pop_pred_stack(&stack); - if (!pred) - return -EINVAL; - /* This item is where we start from in matching */ - root = pred; - /* Make sure the stack is empty */ - pred = __pop_pred_stack(&stack); - if (WARN_ON(pred)) { - err = -EINVAL; - filter->root = NULL; - goto fail; - } - err = check_pred_tree(filter, root); - if (err) - goto fail; - - /* Optimize the tree */ - err = fold_pred_tree(filter, root); - if (err) - goto fail; - - /* We don't set root until we know it works */ - barrier(); - filter->root = root; + if (!nr_preds) { + prog = NULL; + } else { + prog = predicate_parse(filter_string, nr_parens, nr_preds, + parse_pred, call, pe); + if (IS_ERR(prog)) + return PTR_ERR(prog); } - - err = 0; -fail: - __free_pred_stack(&stack); - return err; + rcu_assign_pointer(filter->prog, prog); + return 0; } static inline void event_set_filtered_flag(struct trace_event_file *file) @@ -1780,72 +1558,53 @@ struct filter_list { struct event_filter *filter; }; -static int replace_system_preds(struct trace_subsystem_dir *dir, +static int process_system_preds(struct trace_subsystem_dir *dir, struct trace_array *tr, - struct filter_parse_state *ps, + struct filter_parse_error *pe, char *filter_string) { struct trace_event_file *file; struct filter_list *filter_item; + struct event_filter *filter = NULL; struct filter_list *tmp; LIST_HEAD(filter_list); bool fail = true; int err; list_for_each_entry(file, &tr->events, list) { - if (file->system != dir) - continue; - - /* - * Try to see if the filter can be applied - * (filter arg is ignored on dry_run) - */ - err = replace_preds(file->event_call, NULL, ps, true); - if (err) - event_set_no_set_filter_flag(file); - else - event_clear_no_set_filter_flag(file); - } - - list_for_each_entry(file, &tr->events, list) { - struct event_filter *filter; if (file->system != dir) continue; - if (event_no_set_filter_flag(file)) - continue; - - filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL); - if (!filter_item) - goto fail_mem; - - list_add_tail(&filter_item->list, &filter_list); - - filter_item->filter = __alloc_filter(); - if (!filter_item->filter) + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + if (!filter) goto fail_mem; - filter = filter_item->filter; - /* Can only fail on no memory */ - err = replace_filter_string(filter, filter_string); - if (err) + filter->filter_string = kstrdup(filter_string, GFP_KERNEL); + if (!filter->filter_string) goto fail_mem; - err = replace_preds(file->event_call, filter, ps, false); + err = process_preds(file->event_call, filter_string, filter, pe); if (err) { filter_disable(file); - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); - append_filter_err(ps, filter); + parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0); + append_filter_err(pe, filter); } else event_set_filtered_flag(file); + + + filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL); + if (!filter_item) + goto fail_mem; + + list_add_tail(&filter_item->list, &filter_list); /* * Regardless of if this returned an error, we still * replace the filter for the call. */ - filter = event_filter(file); - event_set_filter(file, filter_item->filter); - filter_item->filter = filter; + filter_item->filter = event_filter(file); + event_set_filter(file, filter); + filter = NULL; fail = false; } @@ -1871,9 +1630,10 @@ static int replace_system_preds(struct trace_subsystem_dir *dir, list_del(&filter_item->list); kfree(filter_item); } - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0); return -EINVAL; fail_mem: + kfree(filter); /* If any call succeeded, we still need to sync */ if (!fail) synchronize_sched(); @@ -1885,47 +1645,42 @@ static int replace_system_preds(struct trace_subsystem_dir *dir, return -ENOMEM; } -static int create_filter_start(char *filter_str, bool set_str, - struct filter_parse_state **psp, +static int create_filter_start(char *filter_string, bool set_str, + struct filter_parse_error **pse, struct event_filter **filterp) { struct event_filter *filter; - struct filter_parse_state *ps = NULL; + struct filter_parse_error *pe = NULL; int err = 0; - WARN_ON_ONCE(*psp || *filterp); + if (WARN_ON_ONCE(*pse || *filterp)) + return -EINVAL; - /* allocate everything, and if any fails, free all and fail */ - filter = __alloc_filter(); - if (filter && set_str) - err = replace_filter_string(filter, filter_str); + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + if (filter && set_str) { + filter->filter_string = kstrdup(filter_string, GFP_KERNEL); + if (!filter->filter_string) + err = -ENOMEM; + } - ps = kzalloc(sizeof(*ps), GFP_KERNEL); + pe = kzalloc(sizeof(*pe), GFP_KERNEL); - if (!filter || !ps || err) { - kfree(ps); + if (!filter || !pe || err) { + kfree(pe); __free_filter(filter); return -ENOMEM; } /* we're committed to creating a new filter */ *filterp = filter; - *psp = ps; + *pse = pe; - parse_init(ps, filter_ops, filter_str); - err = filter_parse(ps); - if (err && set_str) - append_filter_err(ps, filter); - return err; + return 0; } -static void create_filter_finish(struct filter_parse_state *ps) +static void create_filter_finish(struct filter_parse_error *pe) { - if (ps) { - filter_opstack_clear(ps); - postfix_clear(ps); - kfree(ps); - } + kfree(pe); } /** @@ -1945,24 +1700,20 @@ static void create_filter_finish(struct filter_parse_state *ps) * freeing it. */ static int create_filter(struct trace_event_call *call, - char *filter_str, bool set_str, + char *filter_string, bool set_str, struct event_filter **filterp) { + struct filter_parse_error *pe = NULL; struct event_filter *filter = NULL; - struct filter_parse_state *ps = NULL; int err; - err = create_filter_start(filter_str, set_str, &ps, &filter); - if (!err) { - err = replace_preds(call, filter, ps, false); - if (err && set_str) - append_filter_err(ps, filter); - } - if (err && !set_str) { - free_event_filter(filter); - filter = NULL; - } - create_filter_finish(ps); + err = create_filter_start(filter_string, set_str, &pe, &filter); + if (err) + return err; + + err = process_preds(call, filter_string, filter, pe); + if (err && set_str) + append_filter_err(pe, filter); *filterp = filter; return err; @@ -1989,21 +1740,21 @@ static int create_system_filter(struct trace_subsystem_dir *dir, char *filter_str, struct event_filter **filterp) { struct event_filter *filter = NULL; - struct filter_parse_state *ps = NULL; + struct filter_parse_error *pe = NULL; int err; - err = create_filter_start(filter_str, true, &ps, &filter); + err = create_filter_start(filter_str, true, &pe, &filter); if (!err) { - err = replace_system_preds(dir, tr, ps, filter_str); + err = process_system_preds(dir, tr, pe, filter_str); if (!err) { /* System filters just show a default message */ kfree(filter->filter_string); filter->filter_string = NULL; } else { - append_filter_err(ps, filter); + append_filter_err(pe, filter); } } - create_filter_finish(ps); + create_filter_finish(pe); *filterp = filter; return err; @@ -2186,66 +1937,80 @@ static int __ftrace_function_set_filter(int filter, char *buf, int len, return ret; } -static int ftrace_function_check_pred(struct filter_pred *pred, int leaf) +static int ftrace_function_check_pred(struct filter_pred *pred) { struct ftrace_event_field *field = pred->field; - if (leaf) { - /* - * Check the leaf predicate for function trace, verify: - * - only '==' and '!=' is used - * - the 'ip' field is used - */ - if ((pred->op != OP_EQ) && (pred->op != OP_NE)) - return -EINVAL; + /* + * Check the predicate for function trace, verify: + * - only '==' and '!=' is used + * - the 'ip' field is used + */ + if ((pred->op != OP_EQ) && (pred->op != OP_NE)) + return -EINVAL; - if (strcmp(field->name, "ip")) - return -EINVAL; - } else { - /* - * Check the non leaf predicate for function trace, verify: - * - only '||' is used - */ - if (pred->op != OP_OR) - return -EINVAL; - } + if (strcmp(field->name, "ip")) + return -EINVAL; return 0; } -static int ftrace_function_set_filter_cb(enum move_type move, - struct filter_pred *pred, - int *err, void *data) +static int ftrace_function_set_filter_pred(struct filter_pred *pred, + struct function_filter_data *data) { + int ret; + /* Checking the node is valid for function trace. */ - if ((move != MOVE_DOWN) || - (pred->left != FILTER_PRED_INVALID)) { - *err = ftrace_function_check_pred(pred, 0); - } else { - *err = ftrace_function_check_pred(pred, 1); - if (*err) - return WALK_PRED_ABORT; - - *err = __ftrace_function_set_filter(pred->op == OP_EQ, - pred->regex.pattern, - pred->regex.len, - data); - } + ret = ftrace_function_check_pred(pred); + if (ret) + return ret; - return (*err) ? WALK_PRED_ABORT : WALK_PRED_DEFAULT; + return __ftrace_function_set_filter(pred->op == OP_EQ, + pred->regex.pattern, + pred->regex.len, + data); +} + +static bool is_or(struct prog_entry *prog, int i) +{ + int target; + + /* + * Only "||" is allowed for function events, thus, + * all true branches should jump to true, and any + * false branch should jump to false. + */ + target = prog[i].target + 1; + /* True and false have NULL preds (all prog entries should jump to one */ + if (prog[target].pred) + return false; + + /* prog[target].target is 1 for TRUE, 0 for FALSE */ + return prog[i].when_to_branch == prog[target].target; } static int ftrace_function_set_filter(struct perf_event *event, struct event_filter *filter) { + struct prog_entry *prog = rcu_dereference_protected(filter->prog, + lockdep_is_held(&event_mutex)); struct function_filter_data data = { .first_filter = 1, .first_notrace = 1, .ops = &event->ftrace_ops, }; + int i; - return walk_pred_tree(filter->preds, filter->root, - ftrace_function_set_filter_cb, &data); + for (i = 0; prog[i].pred; i++) { + struct filter_pred *pred = prog[i].pred; + + if (!is_or(prog, i)) + return -EINVAL; + + if (ftrace_function_set_filter_pred(pred, &data) < 0) + return -EINVAL; + } + return 0; } #else static int ftrace_function_set_filter(struct perf_event *event, @@ -2388,26 +2153,28 @@ static int test_pred_visited_fn(struct filter_pred *pred, void *event) return 1; } -static int test_walk_pred_cb(enum move_type move, struct filter_pred *pred, - int *err, void *data) +static void update_pred_fn(struct event_filter *filter, char *fields) { - char *fields = data; + struct prog_entry *prog = rcu_dereference_protected(filter->prog, + lockdep_is_held(&event_mutex)); + int i; - if ((move == MOVE_DOWN) && - (pred->left == FILTER_PRED_INVALID)) { + for (i = 0; prog[i].pred; i++) { + struct filter_pred *pred = prog[i].pred; struct ftrace_event_field *field = pred->field; + WARN_ON_ONCE(!pred->fn); + if (!field) { - WARN(1, "all leafs should have field defined"); - return WALK_PRED_DEFAULT; + WARN_ONCE(1, "all leafs should have field defined %d", i); + continue; } + if (!strchr(fields, *field->name)) - return WALK_PRED_DEFAULT; + continue; - WARN_ON(!pred->fn); pred->fn = test_pred_visited_fn; } - return WALK_PRED_DEFAULT; } static __init int ftrace_test_event_filter(void) @@ -2431,20 +2198,22 @@ static __init int ftrace_test_event_filter(void) break; } + /* Needed to dereference filter->prog */ + mutex_lock(&event_mutex); /* * The preemption disabling is not really needed for self * tests, but the rcu dereference will complain without it. */ preempt_disable(); if (*d->not_visited) - walk_pred_tree(filter->preds, filter->root, - test_walk_pred_cb, - d->not_visited); + update_pred_fn(filter, d->not_visited); test_pred_visited = 0; err = filter_match_preds(filter, &d->rec); preempt_enable(); + mutex_unlock(&event_mutex); + __free_filter(filter); if (test_pred_visited) { diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 1e1558c99d56..0d7b3ffbecc2 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -20,15 +20,39 @@ #include <linux/slab.h> #include <linux/stacktrace.h> #include <linux/rculist.h> +#include <linux/tracefs.h> #include "tracing_map.h" #include "trace.h" +#define SYNTH_SYSTEM "synthetic" +#define SYNTH_FIELDS_MAX 16 + +#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */ + struct hist_field; -typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event); +typedef u64 (*hist_field_fn_t) (struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event); #define HIST_FIELD_OPERANDS_MAX 2 +#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX) +#define HIST_ACTIONS_MAX 8 + +enum field_op_id { + FIELD_OP_NONE, + FIELD_OP_PLUS, + FIELD_OP_MINUS, + FIELD_OP_UNARY_MINUS, +}; + +struct hist_var { + char *name; + struct hist_trigger_data *hist_data; + unsigned int idx; +}; struct hist_field { struct ftrace_event_field *field; @@ -37,27 +61,49 @@ struct hist_field { unsigned int size; unsigned int offset; unsigned int is_signed; + const char *type; struct hist_field *operands[HIST_FIELD_OPERANDS_MAX]; + struct hist_trigger_data *hist_data; + struct hist_var var; + enum field_op_id operator; + char *system; + char *event_name; + char *name; + unsigned int var_idx; + unsigned int var_ref_idx; + bool read_once; }; -static u64 hist_field_none(struct hist_field *field, void *event) +static u64 hist_field_none(struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { return 0; } -static u64 hist_field_counter(struct hist_field *field, void *event) +static u64 hist_field_counter(struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { return 1; } -static u64 hist_field_string(struct hist_field *hist_field, void *event) +static u64 hist_field_string(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { char *addr = (char *)(event + hist_field->field->offset); return (u64)(unsigned long)addr; } -static u64 hist_field_dynstring(struct hist_field *hist_field, void *event) +static u64 hist_field_dynstring(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { u32 str_item = *(u32 *)(event + hist_field->field->offset); int str_loc = str_item & 0xffff; @@ -66,24 +112,74 @@ static u64 hist_field_dynstring(struct hist_field *hist_field, void *event) return (u64)(unsigned long)addr; } -static u64 hist_field_pstring(struct hist_field *hist_field, void *event) +static u64 hist_field_pstring(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { char **addr = (char **)(event + hist_field->field->offset); return (u64)(unsigned long)*addr; } -static u64 hist_field_log2(struct hist_field *hist_field, void *event) +static u64 hist_field_log2(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) { struct hist_field *operand = hist_field->operands[0]; - u64 val = operand->fn(operand, event); + u64 val = operand->fn(operand, elt, rbe, event); return (u64) ilog2(roundup_pow_of_two(val)); } +static u64 hist_field_plus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand1 = hist_field->operands[0]; + struct hist_field *operand2 = hist_field->operands[1]; + + u64 val1 = operand1->fn(operand1, elt, rbe, event); + u64 val2 = operand2->fn(operand2, elt, rbe, event); + + return val1 + val2; +} + +static u64 hist_field_minus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand1 = hist_field->operands[0]; + struct hist_field *operand2 = hist_field->operands[1]; + + u64 val1 = operand1->fn(operand1, elt, rbe, event); + u64 val2 = operand2->fn(operand2, elt, rbe, event); + + return val1 - val2; +} + +static u64 hist_field_unary_minus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand = hist_field->operands[0]; + + s64 sval = (s64)operand->fn(operand, elt, rbe, event); + u64 val = (u64)-sval; + + return val; +} + #define DEFINE_HIST_FIELD_FN(type) \ -static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ + static u64 hist_field_##type(struct hist_field *hist_field, \ + struct tracing_map_elt *elt, \ + struct ring_buffer_event *rbe, \ + void *event) \ { \ type *addr = (type *)(event + hist_field->field->offset); \ \ @@ -126,6 +222,19 @@ enum hist_field_flags { HIST_FIELD_FL_SYSCALL = 1 << 7, HIST_FIELD_FL_STACKTRACE = 1 << 8, HIST_FIELD_FL_LOG2 = 1 << 9, + HIST_FIELD_FL_TIMESTAMP = 1 << 10, + HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11, + HIST_FIELD_FL_VAR = 1 << 12, + HIST_FIELD_FL_EXPR = 1 << 13, + HIST_FIELD_FL_VAR_REF = 1 << 14, + HIST_FIELD_FL_CPU = 1 << 15, + HIST_FIELD_FL_ALIAS = 1 << 16, +}; + +struct var_defs { + unsigned int n_vars; + char *name[TRACING_MAP_VARS_MAX]; + char *expr[TRACING_MAP_VARS_MAX]; }; struct hist_trigger_attrs { @@ -133,25 +242,1437 @@ struct hist_trigger_attrs { char *vals_str; char *sort_key_str; char *name; + char *clock; bool pause; bool cont; bool clear; + bool ts_in_usecs; unsigned int map_bits; + + char *assignment_str[TRACING_MAP_VARS_MAX]; + unsigned int n_assignments; + + char *action_str[HIST_ACTIONS_MAX]; + unsigned int n_actions; + + struct var_defs var_defs; +}; + +struct field_var { + struct hist_field *var; + struct hist_field *val; +}; + +struct field_var_hist { + struct hist_trigger_data *hist_data; + char *cmd; }; struct hist_trigger_data { - struct hist_field *fields[TRACING_MAP_FIELDS_MAX]; + struct hist_field *fields[HIST_FIELDS_MAX]; unsigned int n_vals; unsigned int n_keys; unsigned int n_fields; + unsigned int n_vars; unsigned int key_size; struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; unsigned int n_sort_keys; struct trace_event_file *event_file; struct hist_trigger_attrs *attrs; struct tracing_map *map; + bool enable_timestamps; + bool remove; + struct hist_field *var_refs[TRACING_MAP_VARS_MAX]; + unsigned int n_var_refs; + + struct action_data *actions[HIST_ACTIONS_MAX]; + unsigned int n_actions; + + struct hist_field *synth_var_refs[SYNTH_FIELDS_MAX]; + unsigned int n_synth_var_refs; + struct field_var *field_vars[SYNTH_FIELDS_MAX]; + unsigned int n_field_vars; + unsigned int n_field_var_str; + struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX]; + unsigned int n_field_var_hists; + + struct field_var *max_vars[SYNTH_FIELDS_MAX]; + unsigned int n_max_vars; + unsigned int n_max_var_str; +}; + +struct synth_field { + char *type; + char *name; + size_t size; + bool is_signed; + bool is_string; +}; + +struct synth_event { + struct list_head list; + int ref; + char *name; + struct synth_field **fields; + unsigned int n_fields; + unsigned int n_u64; + struct trace_event_class class; + struct trace_event_call call; + struct tracepoint *tp; +}; + +struct action_data; + +typedef void (*action_fn_t) (struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, + struct action_data *data, u64 *var_ref_vals); + +struct action_data { + action_fn_t fn; + unsigned int n_params; + char *params[SYNTH_FIELDS_MAX]; + + union { + struct { + unsigned int var_ref_idx; + char *match_event; + char *match_event_system; + char *synth_event_name; + struct synth_event *synth_event; + } onmatch; + + struct { + char *var_str; + char *fn_name; + unsigned int max_var_ref_idx; + struct hist_field *max_var; + struct hist_field *var; + } onmax; + }; +}; + + +static char last_hist_cmd[MAX_FILTER_STR_VAL]; +static char hist_err_str[MAX_FILTER_STR_VAL]; + +static void last_cmd_set(char *str) +{ + if (!str) + return; + + strncpy(last_hist_cmd, str, MAX_FILTER_STR_VAL - 1); +} + +static void hist_err(char *str, char *var) +{ + int maxlen = MAX_FILTER_STR_VAL - 1; + + if (!str) + return; + + if (strlen(hist_err_str)) + return; + + if (!var) + var = ""; + + if (strlen(hist_err_str) + strlen(str) + strlen(var) > maxlen) + return; + + strcat(hist_err_str, str); + strcat(hist_err_str, var); +} + +static void hist_err_event(char *str, char *system, char *event, char *var) +{ + char err[MAX_FILTER_STR_VAL]; + + if (system && var) + snprintf(err, MAX_FILTER_STR_VAL, "%s.%s.%s", system, event, var); + else if (system) + snprintf(err, MAX_FILTER_STR_VAL, "%s.%s", system, event); + else + strncpy(err, var, MAX_FILTER_STR_VAL); + + hist_err(str, err); +} + +static void hist_err_clear(void) +{ + hist_err_str[0] = '\0'; +} + +static bool have_hist_err(void) +{ + if (strlen(hist_err_str)) + return true; + + return false; +} + +static LIST_HEAD(synth_event_list); +static DEFINE_MUTEX(synth_event_mutex); + +struct synth_trace_event { + struct trace_entry ent; + u64 fields[]; +}; + +static int synth_event_define_fields(struct trace_event_call *call) +{ + struct synth_trace_event trace; + int offset = offsetof(typeof(trace), fields); + struct synth_event *event = call->data; + unsigned int i, size, n_u64; + char *name, *type; + bool is_signed; + int ret = 0; + + for (i = 0, n_u64 = 0; i < event->n_fields; i++) { + size = event->fields[i]->size; + is_signed = event->fields[i]->is_signed; + type = event->fields[i]->type; + name = event->fields[i]->name; + ret = trace_define_field(call, type, name, offset, size, + is_signed, FILTER_OTHER); + if (ret) + break; + + if (event->fields[i]->is_string) { + offset += STR_VAR_LEN_MAX; + n_u64 += STR_VAR_LEN_MAX / sizeof(u64); + } else { + offset += sizeof(u64); + n_u64++; + } + } + + event->n_u64 = n_u64; + + return ret; +} + +static bool synth_field_signed(char *type) +{ + if (strncmp(type, "u", 1) == 0) + return false; + + return true; +} + +static int synth_field_is_string(char *type) +{ + if (strstr(type, "char[") != NULL) + return true; + + return false; +} + +static int synth_field_string_size(char *type) +{ + char buf[4], *end, *start; + unsigned int len; + int size, err; + + start = strstr(type, "char["); + if (start == NULL) + return -EINVAL; + start += strlen("char["); + + end = strchr(type, ']'); + if (!end || end < start) + return -EINVAL; + + len = end - start; + if (len > 3) + return -EINVAL; + + strncpy(buf, start, len); + buf[len] = '\0'; + + err = kstrtouint(buf, 0, &size); + if (err) + return err; + + if (size > STR_VAR_LEN_MAX) + return -EINVAL; + + return size; +} + +static int synth_field_size(char *type) +{ + int size = 0; + + if (strcmp(type, "s64") == 0) + size = sizeof(s64); + else if (strcmp(type, "u64") == 0) + size = sizeof(u64); + else if (strcmp(type, "s32") == 0) + size = sizeof(s32); + else if (strcmp(type, "u32") == 0) + size = sizeof(u32); + else if (strcmp(type, "s16") == 0) + size = sizeof(s16); + else if (strcmp(type, "u16") == 0) + size = sizeof(u16); + else if (strcmp(type, "s8") == 0) + size = sizeof(s8); + else if (strcmp(type, "u8") == 0) + size = sizeof(u8); + else if (strcmp(type, "char") == 0) + size = sizeof(char); + else if (strcmp(type, "unsigned char") == 0) + size = sizeof(unsigned char); + else if (strcmp(type, "int") == 0) + size = sizeof(int); + else if (strcmp(type, "unsigned int") == 0) + size = sizeof(unsigned int); + else if (strcmp(type, "long") == 0) + size = sizeof(long); + else if (strcmp(type, "unsigned long") == 0) + size = sizeof(unsigned long); + else if (strcmp(type, "pid_t") == 0) + size = sizeof(pid_t); + else if (synth_field_is_string(type)) + size = synth_field_string_size(type); + + return size; +} + +static const char *synth_field_fmt(char *type) +{ + const char *fmt = "%llu"; + + if (strcmp(type, "s64") == 0) + fmt = "%lld"; + else if (strcmp(type, "u64") == 0) + fmt = "%llu"; + else if (strcmp(type, "s32") == 0) + fmt = "%d"; + else if (strcmp(type, "u32") == 0) + fmt = "%u"; + else if (strcmp(type, "s16") == 0) + fmt = "%d"; + else if (strcmp(type, "u16") == 0) + fmt = "%u"; + else if (strcmp(type, "s8") == 0) + fmt = "%d"; + else if (strcmp(type, "u8") == 0) + fmt = "%u"; + else if (strcmp(type, "char") == 0) + fmt = "%d"; + else if (strcmp(type, "unsigned char") == 0) + fmt = "%u"; + else if (strcmp(type, "int") == 0) + fmt = "%d"; + else if (strcmp(type, "unsigned int") == 0) + fmt = "%u"; + else if (strcmp(type, "long") == 0) + fmt = "%ld"; + else if (strcmp(type, "unsigned long") == 0) + fmt = "%lu"; + else if (strcmp(type, "pid_t") == 0) + fmt = "%d"; + else if (synth_field_is_string(type)) + fmt = "%s"; + + return fmt; +} + +static enum print_line_t print_synth_event(struct trace_iterator *iter, + int flags, + struct trace_event *event) +{ + struct trace_array *tr = iter->tr; + struct trace_seq *s = &iter->seq; + struct synth_trace_event *entry; + struct synth_event *se; + unsigned int i, n_u64; + char print_fmt[32]; + const char *fmt; + + entry = (struct synth_trace_event *)iter->ent; + se = container_of(event, struct synth_event, call.event); + + trace_seq_printf(s, "%s: ", se->name); + + for (i = 0, n_u64 = 0; i < se->n_fields; i++) { + if (trace_seq_has_overflowed(s)) + goto end; + + fmt = synth_field_fmt(se->fields[i]->type); + + /* parameter types */ + if (tr->trace_flags & TRACE_ITER_VERBOSE) + trace_seq_printf(s, "%s ", fmt); + + snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt); + + /* parameter values */ + if (se->fields[i]->is_string) { + trace_seq_printf(s, print_fmt, se->fields[i]->name, + (char *)&entry->fields[n_u64], + i == se->n_fields - 1 ? "" : " "); + n_u64 += STR_VAR_LEN_MAX / sizeof(u64); + } else { + trace_seq_printf(s, print_fmt, se->fields[i]->name, + entry->fields[n_u64], + i == se->n_fields - 1 ? "" : " "); + n_u64++; + } + } +end: + trace_seq_putc(s, '\n'); + + return trace_handle_return(s); +} + +static struct trace_event_functions synth_event_funcs = { + .trace = print_synth_event +}; + +static notrace void trace_event_raw_event_synth(void *__data, + u64 *var_ref_vals, + unsigned int var_ref_idx) +{ + struct trace_event_file *trace_file = __data; + struct synth_trace_event *entry; + struct trace_event_buffer fbuffer; + struct ring_buffer *buffer; + struct synth_event *event; + unsigned int i, n_u64; + int fields_size = 0; + + event = trace_file->event_call->data; + + if (trace_trigger_soft_disabled(trace_file)) + return; + + fields_size = event->n_u64 * sizeof(u64); + + /* + * Avoid ring buffer recursion detection, as this event + * is being performed within another event. + */ + buffer = trace_file->tr->trace_buffer.buffer; + ring_buffer_nest_start(buffer); + + entry = trace_event_buffer_reserve(&fbuffer, trace_file, + sizeof(*entry) + fields_size); + if (!entry) + goto out; + + for (i = 0, n_u64 = 0; i < event->n_fields; i++) { + if (event->fields[i]->is_string) { + char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i]; + char *str_field = (char *)&entry->fields[n_u64]; + + strscpy(str_field, str_val, STR_VAR_LEN_MAX); + n_u64 += STR_VAR_LEN_MAX / sizeof(u64); + } else { + entry->fields[n_u64] = var_ref_vals[var_ref_idx + i]; + n_u64++; + } + } + + trace_event_buffer_commit(&fbuffer); +out: + ring_buffer_nest_end(buffer); +} + +static void free_synth_event_print_fmt(struct trace_event_call *call) +{ + if (call) { + kfree(call->print_fmt); + call->print_fmt = NULL; + } +} + +static int __set_synth_event_print_fmt(struct synth_event *event, + char *buf, int len) +{ + const char *fmt; + int pos = 0; + int i; + + /* When len=0, we just calculate the needed length */ +#define LEN_OR_ZERO (len ? len - pos : 0) + + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); + for (i = 0; i < event->n_fields; i++) { + fmt = synth_field_fmt(event->fields[i]->type); + pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s", + event->fields[i]->name, fmt, + i == event->n_fields - 1 ? "" : ", "); + } + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); + + for (i = 0; i < event->n_fields; i++) { + pos += snprintf(buf + pos, LEN_OR_ZERO, + ", REC->%s", event->fields[i]->name); + } + +#undef LEN_OR_ZERO + + /* return the length of print_fmt */ + return pos; +} + +static int set_synth_event_print_fmt(struct trace_event_call *call) +{ + struct synth_event *event = call->data; + char *print_fmt; + int len; + + /* First: called with 0 length to calculate the needed length */ + len = __set_synth_event_print_fmt(event, NULL, 0); + + print_fmt = kmalloc(len + 1, GFP_KERNEL); + if (!print_fmt) + return -ENOMEM; + + /* Second: actually write the @print_fmt */ + __set_synth_event_print_fmt(event, print_fmt, len + 1); + call->print_fmt = print_fmt; + + return 0; +} + +static void free_synth_field(struct synth_field *field) +{ + kfree(field->type); + kfree(field->name); + kfree(field); +} + +static struct synth_field *parse_synth_field(char *field_type, + char *field_name) +{ + struct synth_field *field; + int len, ret = 0; + char *array; + + if (field_type[0] == ';') + field_type++; + + len = strlen(field_name); + if (field_name[len - 1] == ';') + field_name[len - 1] = '\0'; + + field = kzalloc(sizeof(*field), GFP_KERNEL); + if (!field) + return ERR_PTR(-ENOMEM); + + len = strlen(field_type) + 1; + array = strchr(field_name, '['); + if (array) + len += strlen(array); + field->type = kzalloc(len, GFP_KERNEL); + if (!field->type) { + ret = -ENOMEM; + goto free; + } + strcat(field->type, field_type); + if (array) { + strcat(field->type, array); + *array = '\0'; + } + + field->size = synth_field_size(field->type); + if (!field->size) { + ret = -EINVAL; + goto free; + } + + if (synth_field_is_string(field->type)) + field->is_string = true; + + field->is_signed = synth_field_signed(field->type); + + field->name = kstrdup(field_name, GFP_KERNEL); + if (!field->name) { + ret = -ENOMEM; + goto free; + } + out: + return field; + free: + free_synth_field(field); + field = ERR_PTR(ret); + goto out; +} + +static void free_synth_tracepoint(struct tracepoint *tp) +{ + if (!tp) + return; + + kfree(tp->name); + kfree(tp); +} + +static struct tracepoint *alloc_synth_tracepoint(char *name) +{ + struct tracepoint *tp; + + tp = kzalloc(sizeof(*tp), GFP_KERNEL); + if (!tp) + return ERR_PTR(-ENOMEM); + + tp->name = kstrdup(name, GFP_KERNEL); + if (!tp->name) { + kfree(tp); + return ERR_PTR(-ENOMEM); + } + + return tp; +} + +typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals, + unsigned int var_ref_idx); + +static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals, + unsigned int var_ref_idx) +{ + struct tracepoint *tp = event->tp; + + if (unlikely(atomic_read(&tp->key.enabled) > 0)) { + struct tracepoint_func *probe_func_ptr; + synth_probe_func_t probe_func; + void *__data; + + if (!(cpu_online(raw_smp_processor_id()))) + return; + + probe_func_ptr = rcu_dereference_sched((tp)->funcs); + if (probe_func_ptr) { + do { + probe_func = probe_func_ptr->func; + __data = probe_func_ptr->data; + probe_func(__data, var_ref_vals, var_ref_idx); + } while ((++probe_func_ptr)->func); + } + } +} + +static struct synth_event *find_synth_event(const char *name) +{ + struct synth_event *event; + + list_for_each_entry(event, &synth_event_list, list) { + if (strcmp(event->name, name) == 0) + return event; + } + + return NULL; +} + +static int register_synth_event(struct synth_event *event) +{ + struct trace_event_call *call = &event->call; + int ret = 0; + + event->call.class = &event->class; + event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL); + if (!event->class.system) { + ret = -ENOMEM; + goto out; + } + + event->tp = alloc_synth_tracepoint(event->name); + if (IS_ERR(event->tp)) { + ret = PTR_ERR(event->tp); + event->tp = NULL; + goto out; + } + + INIT_LIST_HEAD(&call->class->fields); + call->event.funcs = &synth_event_funcs; + call->class->define_fields = synth_event_define_fields; + + ret = register_trace_event(&call->event); + if (!ret) { + ret = -ENODEV; + goto out; + } + call->flags = TRACE_EVENT_FL_TRACEPOINT; + call->class->reg = trace_event_reg; + call->class->probe = trace_event_raw_event_synth; + call->data = event; + call->tp = event->tp; + + ret = trace_add_event_call(call); + if (ret) { + pr_warn("Failed to register synthetic event: %s\n", + trace_event_name(call)); + goto err; + } + + ret = set_synth_event_print_fmt(call); + if (ret < 0) { + trace_remove_event_call(call); + goto err; + } + out: + return ret; + err: + unregister_trace_event(&call->event); + goto out; +} + +static int unregister_synth_event(struct synth_event *event) +{ + struct trace_event_call *call = &event->call; + int ret; + + ret = trace_remove_event_call(call); + + return ret; +} + +static void free_synth_event(struct synth_event *event) +{ + unsigned int i; + + if (!event) + return; + + for (i = 0; i < event->n_fields; i++) + free_synth_field(event->fields[i]); + + kfree(event->fields); + kfree(event->name); + kfree(event->class.system); + free_synth_tracepoint(event->tp); + free_synth_event_print_fmt(&event->call); + kfree(event); +} + +static struct synth_event *alloc_synth_event(char *event_name, int n_fields, + struct synth_field **fields) +{ + struct synth_event *event; + unsigned int i; + + event = kzalloc(sizeof(*event), GFP_KERNEL); + if (!event) { + event = ERR_PTR(-ENOMEM); + goto out; + } + + event->name = kstrdup(event_name, GFP_KERNEL); + if (!event->name) { + kfree(event); + event = ERR_PTR(-ENOMEM); + goto out; + } + + event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL); + if (!event->fields) { + free_synth_event(event); + event = ERR_PTR(-ENOMEM); + goto out; + } + + for (i = 0; i < n_fields; i++) + event->fields[i] = fields[i]; + + event->n_fields = n_fields; + out: + return event; +} + +static void action_trace(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, + struct action_data *data, u64 *var_ref_vals) +{ + struct synth_event *event = data->onmatch.synth_event; + + trace_synth(event, var_ref_vals, data->onmatch.var_ref_idx); +} + +struct hist_var_data { + struct list_head list; + struct hist_trigger_data *hist_data; +}; + +static void add_or_delete_synth_event(struct synth_event *event, int delete) +{ + if (delete) + free_synth_event(event); + else { + mutex_lock(&synth_event_mutex); + if (!find_synth_event(event->name)) + list_add(&event->list, &synth_event_list); + else + free_synth_event(event); + mutex_unlock(&synth_event_mutex); + } +} + +static int create_synth_event(int argc, char **argv) +{ + struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; + struct synth_event *event = NULL; + bool delete_event = false; + int i, n_fields = 0, ret = 0; + char *name; + + mutex_lock(&synth_event_mutex); + + /* + * Argument syntax: + * - Add synthetic event: <event_name> field[;field] ... + * - Remove synthetic event: !<event_name> field[;field] ... + * where 'field' = type field_name + */ + if (argc < 1) { + ret = -EINVAL; + goto out; + } + + name = argv[0]; + if (name[0] == '!') { + delete_event = true; + name++; + } + + event = find_synth_event(name); + if (event) { + if (delete_event) { + if (event->ref) { + event = NULL; + ret = -EBUSY; + goto out; + } + list_del(&event->list); + goto out; + } + event = NULL; + ret = -EEXIST; + goto out; + } else if (delete_event) + goto out; + + if (argc < 2) { + ret = -EINVAL; + goto out; + } + + for (i = 1; i < argc - 1; i++) { + if (strcmp(argv[i], ";") == 0) + continue; + if (n_fields == SYNTH_FIELDS_MAX) { + ret = -EINVAL; + goto err; + } + + field = parse_synth_field(argv[i], argv[i + 1]); + if (IS_ERR(field)) { + ret = PTR_ERR(field); + goto err; + } + fields[n_fields] = field; + i++; n_fields++; + } + + if (i < argc) { + ret = -EINVAL; + goto err; + } + + event = alloc_synth_event(name, n_fields, fields); + if (IS_ERR(event)) { + ret = PTR_ERR(event); + event = NULL; + goto err; + } + out: + mutex_unlock(&synth_event_mutex); + + if (event) { + if (delete_event) { + ret = unregister_synth_event(event); + add_or_delete_synth_event(event, !ret); + } else { + ret = register_synth_event(event); + add_or_delete_synth_event(event, ret); + } + } + + return ret; + err: + mutex_unlock(&synth_event_mutex); + + for (i = 0; i < n_fields; i++) + free_synth_field(fields[i]); + free_synth_event(event); + + return ret; +} + +static int release_all_synth_events(void) +{ + struct list_head release_events; + struct synth_event *event, *e; + int ret = 0; + + INIT_LIST_HEAD(&release_events); + + mutex_lock(&synth_event_mutex); + + list_for_each_entry(event, &synth_event_list, list) { + if (event->ref) { + mutex_unlock(&synth_event_mutex); + return -EBUSY; + } + } + + list_splice_init(&event->list, &release_events); + + mutex_unlock(&synth_event_mutex); + + list_for_each_entry_safe(event, e, &release_events, list) { + list_del(&event->list); + + ret = unregister_synth_event(event); + add_or_delete_synth_event(event, !ret); + } + + return ret; +} + + +static void *synth_events_seq_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&synth_event_mutex); + + return seq_list_start(&synth_event_list, *pos); +} + +static void *synth_events_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &synth_event_list, pos); +} + +static void synth_events_seq_stop(struct seq_file *m, void *v) +{ + mutex_unlock(&synth_event_mutex); +} + +static int synth_events_seq_show(struct seq_file *m, void *v) +{ + struct synth_field *field; + struct synth_event *event = v; + unsigned int i; + + seq_printf(m, "%s\t", event->name); + + for (i = 0; i < event->n_fields; i++) { + field = event->fields[i]; + + /* parameter values */ + seq_printf(m, "%s %s%s", field->type, field->name, + i == event->n_fields - 1 ? "" : "; "); + } + + seq_putc(m, '\n'); + + return 0; +} + +static const struct seq_operations synth_events_seq_op = { + .start = synth_events_seq_start, + .next = synth_events_seq_next, + .stop = synth_events_seq_stop, + .show = synth_events_seq_show +}; + +static int synth_events_open(struct inode *inode, struct file *file) +{ + int ret; + + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { + ret = release_all_synth_events(); + if (ret < 0) + return ret; + } + + return seq_open(file, &synth_events_seq_op); +} + +static ssize_t synth_events_write(struct file *file, + const char __user *buffer, + size_t count, loff_t *ppos) +{ + return trace_parse_run_command(file, buffer, count, ppos, + create_synth_event); +} + +static const struct file_operations synth_events_fops = { + .open = synth_events_open, + .write = synth_events_write, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static u64 hist_field_timestamp(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_trigger_data *hist_data = hist_field->hist_data; + struct trace_array *tr = hist_data->event_file->tr; + + u64 ts = ring_buffer_event_time_stamp(rbe); + + if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr)) + ts = ns2usecs(ts); + + return ts; +} + +static u64 hist_field_cpu(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + int cpu = smp_processor_id(); + + return cpu; +} + +static struct hist_field * +check_field_for_var_ref(struct hist_field *hist_field, + struct hist_trigger_data *var_data, + unsigned int var_idx) +{ + struct hist_field *found = NULL; + + if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF) { + if (hist_field->var.idx == var_idx && + hist_field->var.hist_data == var_data) { + found = hist_field; + } + } + + return found; +} + +static struct hist_field * +check_field_for_var_refs(struct hist_trigger_data *hist_data, + struct hist_field *hist_field, + struct hist_trigger_data *var_data, + unsigned int var_idx, + unsigned int level) +{ + struct hist_field *found = NULL; + unsigned int i; + + if (level > 3) + return found; + + if (!hist_field) + return found; + + found = check_field_for_var_ref(hist_field, var_data, var_idx); + if (found) + return found; + + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) { + struct hist_field *operand; + + operand = hist_field->operands[i]; + found = check_field_for_var_refs(hist_data, operand, var_data, + var_idx, level + 1); + if (found) + return found; + } + + return found; +} + +static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data, + struct hist_trigger_data *var_data, + unsigned int var_idx) +{ + struct hist_field *hist_field, *found = NULL; + unsigned int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + found = check_field_for_var_refs(hist_data, hist_field, + var_data, var_idx, 0); + if (found) + return found; + } + + for (i = 0; i < hist_data->n_synth_var_refs; i++) { + hist_field = hist_data->synth_var_refs[i]; + found = check_field_for_var_refs(hist_data, hist_field, + var_data, var_idx, 0); + if (found) + return found; + } + + return found; +} + +static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data, + unsigned int var_idx) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *found = NULL; + struct hist_var_data *var_data; + + list_for_each_entry(var_data, &tr->hist_vars, list) { + if (var_data->hist_data == hist_data) + continue; + found = find_var_ref(var_data->hist_data, hist_data, var_idx); + if (found) + break; + } + + return found; +} + +static bool check_var_refs(struct hist_trigger_data *hist_data) +{ + struct hist_field *field; + bool found = false; + int i; + + for_each_hist_field(i, hist_data) { + field = hist_data->fields[i]; + if (field && field->flags & HIST_FIELD_FL_VAR) { + if (find_any_var_ref(hist_data, field->var.idx)) { + found = true; + break; + } + } + } + + return found; +} + +static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data, *found = NULL; + + list_for_each_entry(var_data, &tr->hist_vars, list) { + if (var_data->hist_data == hist_data) { + found = var_data; + break; + } + } + + return found; +} + +static bool field_has_hist_vars(struct hist_field *hist_field, + unsigned int level) +{ + int i; + + if (level > 3) + return false; + + if (!hist_field) + return false; + + if (hist_field->flags & HIST_FIELD_FL_VAR || + hist_field->flags & HIST_FIELD_FL_VAR_REF) + return true; + + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) { + struct hist_field *operand; + + operand = hist_field->operands[i]; + if (field_has_hist_vars(operand, level + 1)) + return true; + } + + return false; +} + +static bool has_hist_vars(struct hist_trigger_data *hist_data) +{ + struct hist_field *hist_field; + int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (field_has_hist_vars(hist_field, 0)) + return true; + } + + return false; +} + +static int save_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data; + + var_data = find_hist_vars(hist_data); + if (var_data) + return 0; + + if (trace_array_get(tr) < 0) + return -ENODEV; + + var_data = kzalloc(sizeof(*var_data), GFP_KERNEL); + if (!var_data) { + trace_array_put(tr); + return -ENOMEM; + } + + var_data->hist_data = hist_data; + list_add(&var_data->list, &tr->hist_vars); + + return 0; +} + +static void remove_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data; + + var_data = find_hist_vars(hist_data); + if (!var_data) + return; + + if (WARN_ON(check_var_refs(hist_data))) + return; + + list_del(&var_data->list); + + kfree(var_data); + + trace_array_put(tr); +} + +static struct hist_field *find_var_field(struct hist_trigger_data *hist_data, + const char *var_name) +{ + struct hist_field *hist_field, *found = NULL; + int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR && + strcmp(hist_field->var.name, var_name) == 0) { + found = hist_field; + break; + } + } + + return found; +} + +static struct hist_field *find_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + const char *var_name) +{ + struct hist_trigger_data *test_data; + struct event_trigger_data *test; + struct hist_field *hist_field; + + hist_field = find_var_field(hist_data, var_name); + if (hist_field) + return hist_field; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + test_data = test->private_data; + hist_field = find_var_field(test_data, var_name); + if (hist_field) + return hist_field; + } + } + + return NULL; +} + +static struct trace_event_file *find_var_file(struct trace_array *tr, + char *system, + char *event_name, + char *var_name) +{ + struct hist_trigger_data *var_hist_data; + struct hist_var_data *var_data; + struct trace_event_file *file, *found = NULL; + + if (system) + return find_event_file(tr, system, event_name); + + list_for_each_entry(var_data, &tr->hist_vars, list) { + var_hist_data = var_data->hist_data; + file = var_hist_data->event_file; + if (file == found) + continue; + + if (find_var_field(var_hist_data, var_name)) { + if (found) { + hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name); + return NULL; + } + + found = file; + } + } + + return found; +} + +static struct hist_field *find_file_var(struct trace_event_file *file, + const char *var_name) +{ + struct hist_trigger_data *test_data; + struct event_trigger_data *test; + struct hist_field *hist_field; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + test_data = test->private_data; + hist_field = find_var_field(test_data, var_name); + if (hist_field) + return hist_field; + } + } + + return NULL; +} + +static struct hist_field * +find_match_var(struct hist_trigger_data *hist_data, char *var_name) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field, *found = NULL; + struct trace_event_file *file; + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->fn == action_trace) { + char *system = data->onmatch.match_event_system; + char *event_name = data->onmatch.match_event; + + file = find_var_file(tr, system, event_name, var_name); + if (!file) + continue; + hist_field = find_file_var(file, var_name); + if (hist_field) { + if (found) { + hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name); + return ERR_PTR(-EINVAL); + } + + found = hist_field; + } + } + } + return found; +} + +static struct hist_field *find_event_var(struct hist_trigger_data *hist_data, + char *system, + char *event_name, + char *var_name) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field = NULL; + struct trace_event_file *file; + + if (!system || !event_name) { + hist_field = find_match_var(hist_data, var_name); + if (IS_ERR(hist_field)) + return NULL; + if (hist_field) + return hist_field; + } + + file = find_var_file(tr, system, event_name, var_name); + if (!file) + return NULL; + + hist_field = find_file_var(file, var_name); + + return hist_field; +} + +struct hist_elt_data { + char *comm; + u64 *var_ref_vals; + char *field_var_str[SYNTH_FIELDS_MAX]; }; +static u64 hist_field_var_ref(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_elt_data *elt_data; + u64 var_val = 0; + + elt_data = elt->private_data; + var_val = elt_data->var_ref_vals[hist_field->var_ref_idx]; + + return var_val; +} + +static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key, + u64 *var_ref_vals, bool self) +{ + struct hist_trigger_data *var_data; + struct tracing_map_elt *var_elt; + struct hist_field *hist_field; + unsigned int i, var_idx; + bool resolved = true; + u64 var_val = 0; + + for (i = 0; i < hist_data->n_var_refs; i++) { + hist_field = hist_data->var_refs[i]; + var_idx = hist_field->var.idx; + var_data = hist_field->var.hist_data; + + if (var_data == NULL) { + resolved = false; + break; + } + + if ((self && var_data != hist_data) || + (!self && var_data == hist_data)) + continue; + + var_elt = tracing_map_lookup(var_data->map, key); + if (!var_elt) { + resolved = false; + break; + } + + if (!tracing_map_var_set(var_elt, var_idx)) { + resolved = false; + break; + } + + if (self || !hist_field->read_once) + var_val = tracing_map_read_var(var_elt, var_idx); + else + var_val = tracing_map_read_var_once(var_elt, var_idx); + + var_ref_vals[i] = var_val; + } + + return resolved; +} + static const char *hist_field_name(struct hist_field *field, unsigned int level) { @@ -162,8 +1683,26 @@ static const char *hist_field_name(struct hist_field *field, if (field->field) field_name = field->field->name; - else if (field->flags & HIST_FIELD_FL_LOG2) + else if (field->flags & HIST_FIELD_FL_LOG2 || + field->flags & HIST_FIELD_FL_ALIAS) field_name = hist_field_name(field->operands[0], ++level); + else if (field->flags & HIST_FIELD_FL_CPU) + field_name = "cpu"; + else if (field->flags & HIST_FIELD_FL_EXPR || + field->flags & HIST_FIELD_FL_VAR_REF) { + if (field->system) { + static char full_name[MAX_FILTER_STR_VAL]; + + strcat(full_name, field->system); + strcat(full_name, "."); + strcat(full_name, field->event_name); + strcat(full_name, "."); + strcat(full_name, field->name); + field_name = full_name; + } else + field_name = field->name; + } else if (field->flags & HIST_FIELD_FL_TIMESTAMP) + field_name = "common_timestamp"; if (field_name == NULL) field_name = ""; @@ -232,16 +1771,119 @@ static int parse_map_size(char *str) static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) { + unsigned int i; + if (!attrs) return; + for (i = 0; i < attrs->n_assignments; i++) + kfree(attrs->assignment_str[i]); + + for (i = 0; i < attrs->n_actions; i++) + kfree(attrs->action_str[i]); + kfree(attrs->name); kfree(attrs->sort_key_str); kfree(attrs->keys_str); kfree(attrs->vals_str); + kfree(attrs->clock); kfree(attrs); } +static int parse_action(char *str, struct hist_trigger_attrs *attrs) +{ + int ret = -EINVAL; + + if (attrs->n_actions >= HIST_ACTIONS_MAX) + return ret; + + if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0) || + (strncmp(str, "onmax(", strlen("onmax(")) == 0)) { + attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL); + if (!attrs->action_str[attrs->n_actions]) { + ret = -ENOMEM; + return ret; + } + attrs->n_actions++; + ret = 0; + } + + return ret; +} + +static int parse_assignment(char *str, struct hist_trigger_attrs *attrs) +{ + int ret = 0; + + if ((strncmp(str, "key=", strlen("key=")) == 0) || + (strncmp(str, "keys=", strlen("keys=")) == 0)) { + attrs->keys_str = kstrdup(str, GFP_KERNEL); + if (!attrs->keys_str) { + ret = -ENOMEM; + goto out; + } + } else if ((strncmp(str, "val=", strlen("val=")) == 0) || + (strncmp(str, "vals=", strlen("vals=")) == 0) || + (strncmp(str, "values=", strlen("values=")) == 0)) { + attrs->vals_str = kstrdup(str, GFP_KERNEL); + if (!attrs->vals_str) { + ret = -ENOMEM; + goto out; + } + } else if (strncmp(str, "sort=", strlen("sort=")) == 0) { + attrs->sort_key_str = kstrdup(str, GFP_KERNEL); + if (!attrs->sort_key_str) { + ret = -ENOMEM; + goto out; + } + } else if (strncmp(str, "name=", strlen("name=")) == 0) { + attrs->name = kstrdup(str, GFP_KERNEL); + if (!attrs->name) { + ret = -ENOMEM; + goto out; + } + } else if (strncmp(str, "clock=", strlen("clock=")) == 0) { + strsep(&str, "="); + if (!str) { + ret = -EINVAL; + goto out; + } + + str = strstrip(str); + attrs->clock = kstrdup(str, GFP_KERNEL); + if (!attrs->clock) { + ret = -ENOMEM; + goto out; + } + } else if (strncmp(str, "size=", strlen("size=")) == 0) { + int map_bits = parse_map_size(str); + + if (map_bits < 0) { + ret = map_bits; + goto out; + } + attrs->map_bits = map_bits; + } else { + char *assignment; + + if (attrs->n_assignments == TRACING_MAP_VARS_MAX) { + hist_err("Too many variables defined: ", str); + ret = -EINVAL; + goto out; + } + + assignment = kstrdup(str, GFP_KERNEL); + if (!assignment) { + ret = -ENOMEM; + goto out; + } + + attrs->assignment_str[attrs->n_assignments++] = assignment; + } + out: + return ret; +} + static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) { struct hist_trigger_attrs *attrs; @@ -254,35 +1896,21 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) while (trigger_str) { char *str = strsep(&trigger_str, ":"); - if ((strncmp(str, "key=", strlen("key=")) == 0) || - (strncmp(str, "keys=", strlen("keys=")) == 0)) - attrs->keys_str = kstrdup(str, GFP_KERNEL); - else if ((strncmp(str, "val=", strlen("val=")) == 0) || - (strncmp(str, "vals=", strlen("vals=")) == 0) || - (strncmp(str, "values=", strlen("values=")) == 0)) - attrs->vals_str = kstrdup(str, GFP_KERNEL); - else if (strncmp(str, "sort=", strlen("sort=")) == 0) - attrs->sort_key_str = kstrdup(str, GFP_KERNEL); - else if (strncmp(str, "name=", strlen("name=")) == 0) - attrs->name = kstrdup(str, GFP_KERNEL); - else if (strcmp(str, "pause") == 0) + if (strchr(str, '=')) { + ret = parse_assignment(str, attrs); + if (ret) + goto free; + } else if (strcmp(str, "pause") == 0) attrs->pause = true; else if ((strcmp(str, "cont") == 0) || (strcmp(str, "continue") == 0)) attrs->cont = true; else if (strcmp(str, "clear") == 0) attrs->clear = true; - else if (strncmp(str, "size=", strlen("size=")) == 0) { - int map_bits = parse_map_size(str); - - if (map_bits < 0) { - ret = map_bits; + else { + ret = parse_action(str, attrs); + if (ret) goto free; - } - attrs->map_bits = map_bits; - } else { - ret = -EINVAL; - goto free; } } @@ -291,6 +1919,14 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) goto free; } + if (!attrs->clock) { + attrs->clock = kstrdup("global", GFP_KERNEL); + if (!attrs->clock) { + ret = -ENOMEM; + goto free; + } + } + return attrs; free: destroy_hist_trigger_attrs(attrs); @@ -313,64 +1949,203 @@ static inline void save_comm(char *comm, struct task_struct *task) memcpy(comm, task->comm, TASK_COMM_LEN); } -static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt) +static void hist_elt_data_free(struct hist_elt_data *elt_data) { - kfree((char *)elt->private_data); + unsigned int i; + + for (i = 0; i < SYNTH_FIELDS_MAX; i++) + kfree(elt_data->field_var_str[i]); + + kfree(elt_data->comm); + kfree(elt_data); } -static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt) +static void hist_trigger_elt_data_free(struct tracing_map_elt *elt) +{ + struct hist_elt_data *elt_data = elt->private_data; + + hist_elt_data_free(elt_data); +} + +static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) { struct hist_trigger_data *hist_data = elt->map->private_data; + unsigned int size = TASK_COMM_LEN; + struct hist_elt_data *elt_data; struct hist_field *key_field; - unsigned int i; + unsigned int i, n_str; + + elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); + if (!elt_data) + return -ENOMEM; for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; if (key_field->flags & HIST_FIELD_FL_EXECNAME) { - unsigned int size = TASK_COMM_LEN + 1; - - elt->private_data = kzalloc(size, GFP_KERNEL); - if (!elt->private_data) + elt_data->comm = kzalloc(size, GFP_KERNEL); + if (!elt_data->comm) { + kfree(elt_data); return -ENOMEM; + } break; } } + n_str = hist_data->n_field_var_str + hist_data->n_max_var_str; + + size = STR_VAR_LEN_MAX; + + for (i = 0; i < n_str; i++) { + elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL); + if (!elt_data->field_var_str[i]) { + hist_elt_data_free(elt_data); + return -ENOMEM; + } + } + + elt->private_data = elt_data; + return 0; } -static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to, - struct tracing_map_elt *from) +static void hist_trigger_elt_data_init(struct tracing_map_elt *elt) +{ + struct hist_elt_data *elt_data = elt->private_data; + + if (elt_data->comm) + save_comm(elt_data->comm, current); +} + +static const struct tracing_map_ops hist_trigger_elt_data_ops = { + .elt_alloc = hist_trigger_elt_data_alloc, + .elt_free = hist_trigger_elt_data_free, + .elt_init = hist_trigger_elt_data_init, +}; + +static const char *get_hist_field_flags(struct hist_field *hist_field) +{ + const char *flags_str = NULL; + + if (hist_field->flags & HIST_FIELD_FL_HEX) + flags_str = "hex"; + else if (hist_field->flags & HIST_FIELD_FL_SYM) + flags_str = "sym"; + else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) + flags_str = "sym-offset"; + else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) + flags_str = "execname"; + else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) + flags_str = "syscall"; + else if (hist_field->flags & HIST_FIELD_FL_LOG2) + flags_str = "log2"; + else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS) + flags_str = "usecs"; + + return flags_str; +} + +static void expr_field_str(struct hist_field *field, char *expr) { - char *comm_from = from->private_data; - char *comm_to = to->private_data; + if (field->flags & HIST_FIELD_FL_VAR_REF) + strcat(expr, "$"); + + strcat(expr, hist_field_name(field, 0)); - if (comm_from) - memcpy(comm_to, comm_from, TASK_COMM_LEN + 1); + if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) { + const char *flags_str = get_hist_field_flags(field); + + if (flags_str) { + strcat(expr, "."); + strcat(expr, flags_str); + } + } } -static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt) +static char *expr_str(struct hist_field *field, unsigned int level) { - char *comm = elt->private_data; + char *expr; + + if (level > 1) + return NULL; + + expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!expr) + return NULL; + + if (!field->operands[0]) { + expr_field_str(field, expr); + return expr; + } + + if (field->operator == FIELD_OP_UNARY_MINUS) { + char *subexpr; - if (comm) - save_comm(comm, current); + strcat(expr, "-("); + subexpr = expr_str(field->operands[0], ++level); + if (!subexpr) { + kfree(expr); + return NULL; + } + strcat(expr, subexpr); + strcat(expr, ")"); + + kfree(subexpr); + + return expr; + } + + expr_field_str(field->operands[0], expr); + + switch (field->operator) { + case FIELD_OP_MINUS: + strcat(expr, "-"); + break; + case FIELD_OP_PLUS: + strcat(expr, "+"); + break; + default: + kfree(expr); + return NULL; + } + + expr_field_str(field->operands[1], expr); + + return expr; } -static const struct tracing_map_ops hist_trigger_elt_comm_ops = { - .elt_alloc = hist_trigger_elt_comm_alloc, - .elt_copy = hist_trigger_elt_comm_copy, - .elt_free = hist_trigger_elt_comm_free, - .elt_init = hist_trigger_elt_comm_init, -}; +static int contains_operator(char *str) +{ + enum field_op_id field_op = FIELD_OP_NONE; + char *op; + + op = strpbrk(str, "+-"); + if (!op) + return FIELD_OP_NONE; + + switch (*op) { + case '-': + if (*str == '-') + field_op = FIELD_OP_UNARY_MINUS; + else + field_op = FIELD_OP_MINUS; + break; + case '+': + field_op = FIELD_OP_PLUS; + break; + default: + break; + } + + return field_op; +} static void destroy_hist_field(struct hist_field *hist_field, unsigned int level) { unsigned int i; - if (level > 2) + if (level > 3) return; if (!hist_field) @@ -379,11 +2154,17 @@ static void destroy_hist_field(struct hist_field *hist_field, for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) destroy_hist_field(hist_field->operands[i], level + 1); + kfree(hist_field->var.name); + kfree(hist_field->name); + kfree(hist_field->type); + kfree(hist_field); } -static struct hist_field *create_hist_field(struct ftrace_event_field *field, - unsigned long flags) +static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, + struct ftrace_event_field *field, + unsigned long flags, + char *var_name) { struct hist_field *hist_field; @@ -394,8 +2175,22 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, if (!hist_field) return NULL; + hist_field->hist_data = hist_data; + + if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS) + goto out; /* caller will populate */ + + if (flags & HIST_FIELD_FL_VAR_REF) { + hist_field->fn = hist_field_var_ref; + goto out; + } + if (flags & HIST_FIELD_FL_HITCOUNT) { hist_field->fn = hist_field_counter; + hist_field->size = sizeof(u64); + hist_field->type = kstrdup("u64", GFP_KERNEL); + if (!hist_field->type) + goto free; goto out; } @@ -407,8 +2202,29 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, if (flags & HIST_FIELD_FL_LOG2) { unsigned long fl = flags & ~HIST_FIELD_FL_LOG2; hist_field->fn = hist_field_log2; - hist_field->operands[0] = create_hist_field(field, fl); + hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); hist_field->size = hist_field->operands[0]->size; + hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (flags & HIST_FIELD_FL_TIMESTAMP) { + hist_field->fn = hist_field_timestamp; + hist_field->size = sizeof(u64); + hist_field->type = kstrdup("u64", GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (flags & HIST_FIELD_FL_CPU) { + hist_field->fn = hist_field_cpu; + hist_field->size = sizeof(int); + hist_field->type = kstrdup("unsigned int", GFP_KERNEL); + if (!hist_field->type) + goto free; goto out; } @@ -418,6 +2234,11 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; + hist_field->size = MAX_FILTER_STR_VAL; + hist_field->type = kstrdup(field->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + if (field->filter_type == FILTER_STATIC_STRING) hist_field->fn = hist_field_string; else if (field->filter_type == FILTER_DYN_STRING) @@ -425,6 +2246,12 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, else hist_field->fn = hist_field_pstring; } else { + hist_field->size = field->size; + hist_field->is_signed = field->is_signed; + hist_field->type = kstrdup(field->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + hist_field->fn = select_value_fn(field->size, field->is_signed); if (!hist_field->fn) { @@ -436,14 +2263,23 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, hist_field->field = field; hist_field->flags = flags; + if (var_name) { + hist_field->var.name = kstrdup(var_name, GFP_KERNEL); + if (!hist_field->var.name) + goto free; + } + return hist_field; + free: + destroy_hist_field(hist_field, 0); + return NULL; } static void destroy_hist_fields(struct hist_trigger_data *hist_data) { unsigned int i; - for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) { + for (i = 0; i < HIST_FIELDS_MAX; i++) { if (hist_data->fields[i]) { destroy_hist_field(hist_data->fields[i], 0); hist_data->fields[i] = NULL; @@ -451,69 +2287,1610 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data) } } -static int create_hitcount_val(struct hist_trigger_data *hist_data) +static int init_var_ref(struct hist_field *ref_field, + struct hist_field *var_field, + char *system, char *event_name) { - hist_data->fields[HITCOUNT_IDX] = - create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT); - if (!hist_data->fields[HITCOUNT_IDX]) - return -ENOMEM; + int err = 0; + + ref_field->var.idx = var_field->var.idx; + ref_field->var.hist_data = var_field->hist_data; + ref_field->size = var_field->size; + ref_field->is_signed = var_field->is_signed; + ref_field->flags |= var_field->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + + if (system) { + ref_field->system = kstrdup(system, GFP_KERNEL); + if (!ref_field->system) + return -ENOMEM; + } - hist_data->n_vals++; + if (event_name) { + ref_field->event_name = kstrdup(event_name, GFP_KERNEL); + if (!ref_field->event_name) { + err = -ENOMEM; + goto free; + } + } - if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + if (var_field->var.name) { + ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL); + if (!ref_field->name) { + err = -ENOMEM; + goto free; + } + } else if (var_field->name) { + ref_field->name = kstrdup(var_field->name, GFP_KERNEL); + if (!ref_field->name) { + err = -ENOMEM; + goto free; + } + } + + ref_field->type = kstrdup(var_field->type, GFP_KERNEL); + if (!ref_field->type) { + err = -ENOMEM; + goto free; + } + out: + return err; + free: + kfree(ref_field->system); + kfree(ref_field->event_name); + kfree(ref_field->name); + + goto out; +} + +static struct hist_field *create_var_ref(struct hist_field *var_field, + char *system, char *event_name) +{ + unsigned long flags = HIST_FIELD_FL_VAR_REF; + struct hist_field *ref_field; + + ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL); + if (ref_field) { + if (init_var_ref(ref_field, var_field, system, event_name)) { + destroy_hist_field(ref_field, 0); + return NULL; + } + } + + return ref_field; +} + +static bool is_var_ref(char *var_name) +{ + if (!var_name || strlen(var_name) < 2 || var_name[0] != '$') + return false; + + return true; +} + +static char *field_name_from_var(struct hist_trigger_data *hist_data, + char *var_name) +{ + char *name, *field; + unsigned int i; + + for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { + name = hist_data->attrs->var_defs.name[i]; + + if (strcmp(var_name, name) == 0) { + field = hist_data->attrs->var_defs.expr[i]; + if (contains_operator(field) || is_var_ref(field)) + continue; + return field; + } + } + + return NULL; +} + +static char *local_field_var_ref(struct hist_trigger_data *hist_data, + char *system, char *event_name, + char *var_name) +{ + struct trace_event_call *call; + + if (system && event_name) { + call = hist_data->event_file->event_call; + + if (strcmp(system, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + if (!!system != !!event_name) + return NULL; + + if (!is_var_ref(var_name)) + return NULL; + + var_name++; + + return field_name_from_var(hist_data, var_name); +} + +static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data, + char *system, char *event_name, + char *var_name) +{ + struct hist_field *var_field = NULL, *ref_field = NULL; + + if (!is_var_ref(var_name)) + return NULL; + + var_name++; + + var_field = find_event_var(hist_data, system, event_name, var_name); + if (var_field) + ref_field = create_var_ref(var_field, system, event_name); + + if (!ref_field) + hist_err_event("Couldn't find variable: $", + system, event_name, var_name); + + return ref_field; +} + +static struct ftrace_event_field * +parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, + char *field_str, unsigned long *flags) +{ + struct ftrace_event_field *field = NULL; + char *field_name, *modifier, *str; + + modifier = str = kstrdup(field_str, GFP_KERNEL); + if (!modifier) + return ERR_PTR(-ENOMEM); + + field_name = strsep(&modifier, "."); + if (modifier) { + if (strcmp(modifier, "hex") == 0) + *flags |= HIST_FIELD_FL_HEX; + else if (strcmp(modifier, "sym") == 0) + *flags |= HIST_FIELD_FL_SYM; + else if (strcmp(modifier, "sym-offset") == 0) + *flags |= HIST_FIELD_FL_SYM_OFFSET; + else if ((strcmp(modifier, "execname") == 0) && + (strcmp(field_name, "common_pid") == 0)) + *flags |= HIST_FIELD_FL_EXECNAME; + else if (strcmp(modifier, "syscall") == 0) + *flags |= HIST_FIELD_FL_SYSCALL; + else if (strcmp(modifier, "log2") == 0) + *flags |= HIST_FIELD_FL_LOG2; + else if (strcmp(modifier, "usecs") == 0) + *flags |= HIST_FIELD_FL_TIMESTAMP_USECS; + else { + field = ERR_PTR(-EINVAL); + goto out; + } + } + + if (strcmp(field_name, "common_timestamp") == 0) { + *flags |= HIST_FIELD_FL_TIMESTAMP; + hist_data->enable_timestamps = true; + if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS) + hist_data->attrs->ts_in_usecs = true; + } else if (strcmp(field_name, "cpu") == 0) + *flags |= HIST_FIELD_FL_CPU; + else { + field = trace_find_event_field(file->event_call, field_name); + if (!field || !field->size) { + field = ERR_PTR(-EINVAL); + goto out; + } + } + out: + kfree(str); + + return field; +} + +static struct hist_field *create_alias(struct hist_trigger_data *hist_data, + struct hist_field *var_ref, + char *var_name) +{ + struct hist_field *alias = NULL; + unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR; + + alias = create_hist_field(hist_data, NULL, flags, var_name); + if (!alias) + return NULL; + + alias->fn = var_ref->fn; + alias->operands[0] = var_ref; + + if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) { + destroy_hist_field(alias, 0); + return NULL; + } + + return alias; +} + +static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, + struct trace_event_file *file, char *str, + unsigned long *flags, char *var_name) +{ + char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str; + struct ftrace_event_field *field = NULL; + struct hist_field *hist_field = NULL; + int ret = 0; + + s = strchr(str, '.'); + if (s) { + s = strchr(++s, '.'); + if (s) { + ref_system = strsep(&str, "."); + if (!str) { + ret = -EINVAL; + goto out; + } + ref_event = strsep(&str, "."); + if (!str) { + ret = -EINVAL; + goto out; + } + ref_var = str; + } + } + + s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var); + if (!s) { + hist_field = parse_var_ref(hist_data, ref_system, ref_event, ref_var); + if (hist_field) { + hist_data->var_refs[hist_data->n_var_refs] = hist_field; + hist_field->var_ref_idx = hist_data->n_var_refs++; + if (var_name) { + hist_field = create_alias(hist_data, hist_field, var_name); + if (!hist_field) { + ret = -ENOMEM; + goto out; + } + } + return hist_field; + } + } else + str = s; + + field = parse_field(hist_data, file, str, flags); + if (IS_ERR(field)) { + ret = PTR_ERR(field); + goto out; + } + + hist_field = create_hist_field(hist_data, field, *flags, var_name); + if (!hist_field) { + ret = -ENOMEM; + goto out; + } + + return hist_field; + out: + return ERR_PTR(ret); +} + +static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level); + +static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level) +{ + struct hist_field *operand1, *expr = NULL; + unsigned long operand_flags; + int ret = 0; + char *s; + + /* we support only -(xxx) i.e. explicit parens required */ + + if (level > 3) { + hist_err("Too many subexpressions (3 max): ", str); + ret = -EINVAL; + goto free; + } + + str++; /* skip leading '-' */ + + s = strchr(str, '('); + if (s) + str++; + else { + ret = -EINVAL; + goto free; + } + + s = strrchr(str, ')'); + if (s) + *s = '\0'; + else { + ret = -EINVAL; /* no closing ')' */ + goto free; + } + + flags |= HIST_FIELD_FL_EXPR; + expr = create_hist_field(hist_data, NULL, flags, var_name); + if (!expr) { + ret = -ENOMEM; + goto free; + } + + operand_flags = 0; + operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level); + if (IS_ERR(operand1)) { + ret = PTR_ERR(operand1); + goto free; + } + + expr->flags |= operand1->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + expr->fn = hist_field_unary_minus; + expr->operands[0] = operand1; + expr->operator = FIELD_OP_UNARY_MINUS; + expr->name = expr_str(expr, 0); + expr->type = kstrdup(operand1->type, GFP_KERNEL); + if (!expr->type) { + ret = -ENOMEM; + goto free; + } + + return expr; + free: + destroy_hist_field(expr, 0); + return ERR_PTR(ret); +} + +static int check_expr_operands(struct hist_field *operand1, + struct hist_field *operand2) +{ + unsigned long operand1_flags = operand1->flags; + unsigned long operand2_flags = operand2->flags; + + if ((operand1_flags & HIST_FIELD_FL_VAR_REF) || + (operand1_flags & HIST_FIELD_FL_ALIAS)) { + struct hist_field *var; + + var = find_var_field(operand1->var.hist_data, operand1->name); + if (!var) + return -EINVAL; + operand1_flags = var->flags; + } + + if ((operand2_flags & HIST_FIELD_FL_VAR_REF) || + (operand2_flags & HIST_FIELD_FL_ALIAS)) { + struct hist_field *var; + + var = find_var_field(operand2->var.hist_data, operand2->name); + if (!var) + return -EINVAL; + operand2_flags = var->flags; + } + + if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) != + (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) { + hist_err("Timestamp units in expression don't match", NULL); return -EINVAL; + } return 0; } -static int create_val_field(struct hist_trigger_data *hist_data, - unsigned int val_idx, - struct trace_event_file *file, - char *field_str) +static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level) { - struct ftrace_event_field *field = NULL; - unsigned long flags = 0; - char *field_name; + struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL; + unsigned long operand_flags; + int field_op, ret = -EINVAL; + char *sep, *operand1_str; + + if (level > 3) { + hist_err("Too many subexpressions (3 max): ", str); + return ERR_PTR(-EINVAL); + } + + field_op = contains_operator(str); + + if (field_op == FIELD_OP_NONE) + return parse_atom(hist_data, file, str, &flags, var_name); + + if (field_op == FIELD_OP_UNARY_MINUS) + return parse_unary(hist_data, file, str, flags, var_name, ++level); + + switch (field_op) { + case FIELD_OP_MINUS: + sep = "-"; + break; + case FIELD_OP_PLUS: + sep = "+"; + break; + default: + goto free; + } + + operand1_str = strsep(&str, sep); + if (!operand1_str || !str) + goto free; + + operand_flags = 0; + operand1 = parse_atom(hist_data, file, operand1_str, + &operand_flags, NULL); + if (IS_ERR(operand1)) { + ret = PTR_ERR(operand1); + operand1 = NULL; + goto free; + } + + /* rest of string could be another expression e.g. b+c in a+b+c */ + operand_flags = 0; + operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level); + if (IS_ERR(operand2)) { + ret = PTR_ERR(operand2); + operand2 = NULL; + goto free; + } + + ret = check_expr_operands(operand1, operand2); + if (ret) + goto free; + + flags |= HIST_FIELD_FL_EXPR; + + flags |= operand1->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + + expr = create_hist_field(hist_data, NULL, flags, var_name); + if (!expr) { + ret = -ENOMEM; + goto free; + } + + operand1->read_once = true; + operand2->read_once = true; + + expr->operands[0] = operand1; + expr->operands[1] = operand2; + expr->operator = field_op; + expr->name = expr_str(expr, 0); + expr->type = kstrdup(operand1->type, GFP_KERNEL); + if (!expr->type) { + ret = -ENOMEM; + goto free; + } + + switch (field_op) { + case FIELD_OP_MINUS: + expr->fn = hist_field_minus; + break; + case FIELD_OP_PLUS: + expr->fn = hist_field_plus; + break; + default: + ret = -EINVAL; + goto free; + } + + return expr; + free: + destroy_hist_field(operand1, 0); + destroy_hist_field(operand2, 0); + destroy_hist_field(expr, 0); + + return ERR_PTR(ret); +} + +static char *find_trigger_filter(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (test->private_data == hist_data) + return test->filter_str; + } + } + + return NULL; +} + +static struct event_command trigger_hist_cmd; +static int event_hist_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param); + +static bool compatible_keys(struct hist_trigger_data *target_hist_data, + struct hist_trigger_data *hist_data, + unsigned int n_keys) +{ + struct hist_field *target_hist_field, *hist_field; + unsigned int n, i, j; + + if (hist_data->n_fields - hist_data->n_vals != n_keys) + return false; + + i = hist_data->n_vals; + j = target_hist_data->n_vals; + + for (n = 0; n < n_keys; n++) { + hist_field = hist_data->fields[i + n]; + target_hist_field = target_hist_data->fields[j + n]; + + if (strcmp(hist_field->type, target_hist_field->type) != 0) + return false; + if (hist_field->size != target_hist_field->size) + return false; + if (hist_field->is_signed != target_hist_field->is_signed) + return false; + } + + return true; +} + +static struct hist_trigger_data * +find_compatible_hist(struct hist_trigger_data *target_hist_data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + struct event_trigger_data *test; + unsigned int n_keys; + + n_keys = target_hist_data->n_fields - target_hist_data->n_vals; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; + + if (compatible_keys(target_hist_data, hist_data, n_keys)) + return hist_data; + } + } + + return NULL; +} + +static struct trace_event_file *event_file(struct trace_array *tr, + char *system, char *event_name) +{ + struct trace_event_file *file; + + file = find_event_file(tr, system, event_name); + if (!file) + return ERR_PTR(-EINVAL); + + return file; +} + +static struct hist_field * +find_synthetic_field_var(struct hist_trigger_data *target_hist_data, + char *system, char *event_name, char *field_name) +{ + struct hist_field *event_var; + char *synthetic_name; + + synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!synthetic_name) + return ERR_PTR(-ENOMEM); + + strcpy(synthetic_name, "synthetic_"); + strcat(synthetic_name, field_name); + + event_var = find_event_var(target_hist_data, system, event_name, synthetic_name); + + kfree(synthetic_name); + + return event_var; +} + +/** + * create_field_var_hist - Automatically create a histogram and var for a field + * @target_hist_data: The target hist trigger + * @subsys_name: Optional subsystem name + * @event_name: Optional event name + * @field_name: The name of the field (and the resulting variable) + * + * Hist trigger actions fetch data from variables, not directly from + * events. However, for convenience, users are allowed to directly + * specify an event field in an action, which will be automatically + * converted into a variable on their behalf. + + * If a user specifies a field on an event that isn't the event the + * histogram currently being defined (the target event histogram), the + * only way that can be accomplished is if a new hist trigger is + * created and the field variable defined on that. + * + * This function creates a new histogram compatible with the target + * event (meaning a histogram with the same key as the target + * histogram), and creates a variable for the specified field, but + * with 'synthetic_' prepended to the variable name in order to avoid + * collision with normal field variables. + * + * Return: The variable created for the field. + */ +static struct hist_field * +create_field_var_hist(struct hist_trigger_data *target_hist_data, + char *subsys_name, char *event_name, char *field_name) +{ + struct trace_array *tr = target_hist_data->event_file->tr; + struct hist_field *event_var = ERR_PTR(-EINVAL); + struct hist_trigger_data *hist_data; + unsigned int i, n, first = true; + struct field_var_hist *var_hist; + struct trace_event_file *file; + struct hist_field *key_field; + char *saved_filter; + char *cmd; + int ret; + + if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) { + hist_err_event("onmatch: Too many field variables defined: ", + subsys_name, event_name, field_name); + return ERR_PTR(-EINVAL); + } + + file = event_file(tr, subsys_name, event_name); + + if (IS_ERR(file)) { + hist_err_event("onmatch: Event file not found: ", + subsys_name, event_name, field_name); + ret = PTR_ERR(file); + return ERR_PTR(ret); + } + + /* + * Look for a histogram compatible with target. We'll use the + * found histogram specification to create a new matching + * histogram with our variable on it. target_hist_data is not + * yet a registered histogram so we can't use that. + */ + hist_data = find_compatible_hist(target_hist_data, file); + if (!hist_data) { + hist_err_event("onmatch: Matching event histogram not found: ", + subsys_name, event_name, field_name); + return ERR_PTR(-EINVAL); + } + + /* See if a synthetic field variable has already been created */ + event_var = find_synthetic_field_var(target_hist_data, subsys_name, + event_name, field_name); + if (!IS_ERR_OR_NULL(event_var)) + return event_var; + + var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL); + if (!var_hist) + return ERR_PTR(-ENOMEM); + + cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!cmd) { + kfree(var_hist); + return ERR_PTR(-ENOMEM); + } + + /* Use the same keys as the compatible histogram */ + strcat(cmd, "keys="); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + if (!first) + strcat(cmd, ","); + strcat(cmd, key_field->field->name); + first = false; + } + + /* Create the synthetic field variable specification */ + strcat(cmd, ":synthetic_"); + strcat(cmd, field_name); + strcat(cmd, "="); + strcat(cmd, field_name); + + /* Use the same filter as the compatible histogram */ + saved_filter = find_trigger_filter(hist_data, file); + if (saved_filter) { + strcat(cmd, " if "); + strcat(cmd, saved_filter); + } + + var_hist->cmd = kstrdup(cmd, GFP_KERNEL); + if (!var_hist->cmd) { + kfree(cmd); + kfree(var_hist); + return ERR_PTR(-ENOMEM); + } + + /* Save the compatible histogram information */ + var_hist->hist_data = hist_data; + + /* Create the new histogram with our variable */ + ret = event_hist_trigger_func(&trigger_hist_cmd, file, + "", "hist", cmd); + if (ret) { + kfree(cmd); + kfree(var_hist->cmd); + kfree(var_hist); + hist_err_event("onmatch: Couldn't create histogram for field: ", + subsys_name, event_name, field_name); + return ERR_PTR(ret); + } + + kfree(cmd); + + /* If we can't find the variable, something went wrong */ + event_var = find_synthetic_field_var(target_hist_data, subsys_name, + event_name, field_name); + if (IS_ERR_OR_NULL(event_var)) { + kfree(var_hist->cmd); + kfree(var_hist); + hist_err_event("onmatch: Couldn't find synthetic variable: ", + subsys_name, event_name, field_name); + return ERR_PTR(-EINVAL); + } + + n = target_hist_data->n_field_var_hists; + target_hist_data->field_var_hists[n] = var_hist; + target_hist_data->n_field_var_hists++; + + return event_var; +} + +static struct hist_field * +find_target_event_var(struct hist_trigger_data *hist_data, + char *subsys_name, char *event_name, char *var_name) +{ + struct trace_event_file *file = hist_data->event_file; + struct hist_field *hist_field = NULL; + + if (subsys_name) { + struct trace_event_call *call; + + if (!event_name) + return NULL; + + call = file->event_call; + + if (strcmp(subsys_name, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + hist_field = find_var_field(hist_data, var_name); + + return hist_field; +} + +static inline void __update_field_vars(struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *rec, + struct field_var **field_vars, + unsigned int n_field_vars, + unsigned int field_var_str_start) +{ + struct hist_elt_data *elt_data = elt->private_data; + unsigned int i, j, var_idx; + u64 var_val; + + for (i = 0, j = field_var_str_start; i < n_field_vars; i++) { + struct field_var *field_var = field_vars[i]; + struct hist_field *var = field_var->var; + struct hist_field *val = field_var->val; + + var_val = val->fn(val, elt, rbe, rec); + var_idx = var->var.idx; + + if (val->flags & HIST_FIELD_FL_STRING) { + char *str = elt_data->field_var_str[j++]; + char *val_str = (char *)(uintptr_t)var_val; + + strscpy(str, val_str, STR_VAR_LEN_MAX); + var_val = (u64)(uintptr_t)str; + } + tracing_map_set_var(elt, var_idx, var_val); + } +} + +static void update_field_vars(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *rec) +{ + __update_field_vars(elt, rbe, rec, hist_data->field_vars, + hist_data->n_field_vars, 0); +} + +static void update_max_vars(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *rec) +{ + __update_field_vars(elt, rbe, rec, hist_data->max_vars, + hist_data->n_max_vars, hist_data->n_field_var_str); +} + +static struct hist_field *create_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *name, int size, const char *type) +{ + struct hist_field *var; + int idx; + + if (find_var(hist_data, file, name) && !hist_data->remove) { + var = ERR_PTR(-EINVAL); + goto out; + } + + var = kzalloc(sizeof(struct hist_field), GFP_KERNEL); + if (!var) { + var = ERR_PTR(-ENOMEM); + goto out; + } + + idx = tracing_map_add_var(hist_data->map); + if (idx < 0) { + kfree(var); + var = ERR_PTR(-EINVAL); + goto out; + } + + var->flags = HIST_FIELD_FL_VAR; + var->var.idx = idx; + var->var.hist_data = var->hist_data = hist_data; + var->size = size; + var->var.name = kstrdup(name, GFP_KERNEL); + var->type = kstrdup(type, GFP_KERNEL); + if (!var->var.name || !var->type) { + kfree(var->var.name); + kfree(var->type); + kfree(var); + var = ERR_PTR(-ENOMEM); + } + out: + return var; +} + +static struct field_var *create_field_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *field_name) +{ + struct hist_field *val = NULL, *var = NULL; + unsigned long flags = HIST_FIELD_FL_VAR; + struct field_var *field_var; int ret = 0; - if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) + if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) { + hist_err("Too many field variables defined: ", field_name); + ret = -EINVAL; + goto err; + } + + val = parse_atom(hist_data, file, field_name, &flags, NULL); + if (IS_ERR(val)) { + hist_err("Couldn't parse field variable: ", field_name); + ret = PTR_ERR(val); + goto err; + } + + var = create_var(hist_data, file, field_name, val->size, val->type); + if (IS_ERR(var)) { + hist_err("Couldn't create or find variable: ", field_name); + kfree(val); + ret = PTR_ERR(var); + goto err; + } + + field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL); + if (!field_var) { + kfree(val); + kfree(var); + ret = -ENOMEM; + goto err; + } + + field_var->var = var; + field_var->val = val; + out: + return field_var; + err: + field_var = ERR_PTR(ret); + goto out; +} + +/** + * create_target_field_var - Automatically create a variable for a field + * @target_hist_data: The target hist trigger + * @subsys_name: Optional subsystem name + * @event_name: Optional event name + * @var_name: The name of the field (and the resulting variable) + * + * Hist trigger actions fetch data from variables, not directly from + * events. However, for convenience, users are allowed to directly + * specify an event field in an action, which will be automatically + * converted into a variable on their behalf. + + * This function creates a field variable with the name var_name on + * the hist trigger currently being defined on the target event. If + * subsys_name and event_name are specified, this function simply + * verifies that they do in fact match the target event subsystem and + * event name. + * + * Return: The variable created for the field. + */ +static struct field_var * +create_target_field_var(struct hist_trigger_data *target_hist_data, + char *subsys_name, char *event_name, char *var_name) +{ + struct trace_event_file *file = target_hist_data->event_file; + + if (subsys_name) { + struct trace_event_call *call; + + if (!event_name) + return NULL; + + call = file->event_call; + + if (strcmp(subsys_name, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + return create_field_var(target_hist_data, file, var_name); +} + +static void onmax_print(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct action_data *data) +{ + unsigned int i, save_var_idx, max_idx = data->onmax.max_var->var.idx; + + seq_printf(m, "\n\tmax: %10llu", tracing_map_read_var(elt, max_idx)); + + for (i = 0; i < hist_data->n_max_vars; i++) { + struct hist_field *save_val = hist_data->max_vars[i]->val; + struct hist_field *save_var = hist_data->max_vars[i]->var; + u64 val; + + save_var_idx = save_var->var.idx; + + val = tracing_map_read_var(elt, save_var_idx); + + if (save_val->flags & HIST_FIELD_FL_STRING) { + seq_printf(m, " %s: %-32s", save_var->var.name, + (char *)(uintptr_t)(val)); + } else + seq_printf(m, " %s: %10llu", save_var->var.name, val); + } +} + +static void onmax_save(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, + struct action_data *data, u64 *var_ref_vals) +{ + unsigned int max_idx = data->onmax.max_var->var.idx; + unsigned int max_var_ref_idx = data->onmax.max_var_ref_idx; + + u64 var_val, max_val; + + var_val = var_ref_vals[max_var_ref_idx]; + max_val = tracing_map_read_var(elt, max_idx); + + if (var_val <= max_val) + return; + + tracing_map_set_var(elt, max_idx, var_val); + + update_max_vars(hist_data, elt, rbe, rec); +} + +static void onmax_destroy(struct action_data *data) +{ + unsigned int i; + + destroy_hist_field(data->onmax.max_var, 0); + destroy_hist_field(data->onmax.var, 0); + + kfree(data->onmax.var_str); + kfree(data->onmax.fn_name); + + for (i = 0; i < data->n_params; i++) + kfree(data->params[i]); + + kfree(data); +} + +static int onmax_create(struct hist_trigger_data *hist_data, + struct action_data *data) +{ + struct trace_event_file *file = hist_data->event_file; + struct hist_field *var_field, *ref_field, *max_var; + unsigned int var_ref_idx = hist_data->n_var_refs; + struct field_var *field_var; + char *onmax_var_str, *param; + unsigned long flags; + unsigned int i; + int ret = 0; + + onmax_var_str = data->onmax.var_str; + if (onmax_var_str[0] != '$') { + hist_err("onmax: For onmax(x), x must be a variable: ", onmax_var_str); return -EINVAL; + } + onmax_var_str++; - field_name = strsep(&field_str, "."); - if (field_str) { - if (strcmp(field_str, "hex") == 0) - flags |= HIST_FIELD_FL_HEX; - else { + var_field = find_target_event_var(hist_data, NULL, NULL, onmax_var_str); + if (!var_field) { + hist_err("onmax: Couldn't find onmax variable: ", onmax_var_str); + return -EINVAL; + } + + flags = HIST_FIELD_FL_VAR_REF; + ref_field = create_hist_field(hist_data, NULL, flags, NULL); + if (!ref_field) + return -ENOMEM; + + if (init_var_ref(ref_field, var_field, NULL, NULL)) { + destroy_hist_field(ref_field, 0); + ret = -ENOMEM; + goto out; + } + hist_data->var_refs[hist_data->n_var_refs] = ref_field; + ref_field->var_ref_idx = hist_data->n_var_refs++; + data->onmax.var = ref_field; + + data->fn = onmax_save; + data->onmax.max_var_ref_idx = var_ref_idx; + max_var = create_var(hist_data, file, "max", sizeof(u64), "u64"); + if (IS_ERR(max_var)) { + hist_err("onmax: Couldn't create onmax variable: ", "max"); + ret = PTR_ERR(max_var); + goto out; + } + data->onmax.max_var = max_var; + + for (i = 0; i < data->n_params; i++) { + param = kstrdup(data->params[i], GFP_KERNEL); + if (!param) { + ret = -ENOMEM; + goto out; + } + + field_var = create_target_field_var(hist_data, NULL, NULL, param); + if (IS_ERR(field_var)) { + hist_err("onmax: Couldn't create field variable: ", param); + ret = PTR_ERR(field_var); + kfree(param); + goto out; + } + + hist_data->max_vars[hist_data->n_max_vars++] = field_var; + if (field_var->val->flags & HIST_FIELD_FL_STRING) + hist_data->n_max_var_str++; + + kfree(param); + } + out: + return ret; +} + +static int parse_action_params(char *params, struct action_data *data) +{ + char *param, *saved_param; + int ret = 0; + + while (params) { + if (data->n_params >= SYNTH_FIELDS_MAX) + goto out; + + param = strsep(¶ms, ","); + if (!param) { ret = -EINVAL; goto out; } + + param = strstrip(param); + if (strlen(param) < 2) { + hist_err("Invalid action param: ", param); + ret = -EINVAL; + goto out; + } + + saved_param = kstrdup(param, GFP_KERNEL); + if (!saved_param) { + ret = -ENOMEM; + goto out; + } + + data->params[data->n_params++] = saved_param; } + out: + return ret; +} - field = trace_find_event_field(file->event_call, field_name); - if (!field || !field->size) { +static struct action_data *onmax_parse(char *str) +{ + char *onmax_fn_name, *onmax_var_str; + struct action_data *data; + int ret = -EINVAL; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return ERR_PTR(-ENOMEM); + + onmax_var_str = strsep(&str, ")"); + if (!onmax_var_str || !str) { ret = -EINVAL; - goto out; + goto free; + } + + data->onmax.var_str = kstrdup(onmax_var_str, GFP_KERNEL); + if (!data->onmax.var_str) { + ret = -ENOMEM; + goto free; + } + + strsep(&str, "."); + if (!str) + goto free; + + onmax_fn_name = strsep(&str, "("); + if (!onmax_fn_name || !str) + goto free; + + if (strncmp(onmax_fn_name, "save", strlen("save")) == 0) { + char *params = strsep(&str, ")"); + + if (!params) { + ret = -EINVAL; + goto free; + } + + ret = parse_action_params(params, data); + if (ret) + goto free; + } else + goto free; + + data->onmax.fn_name = kstrdup(onmax_fn_name, GFP_KERNEL); + if (!data->onmax.fn_name) { + ret = -ENOMEM; + goto free; + } + out: + return data; + free: + onmax_destroy(data); + data = ERR_PTR(ret); + goto out; +} + +static void onmatch_destroy(struct action_data *data) +{ + unsigned int i; + + mutex_lock(&synth_event_mutex); + + kfree(data->onmatch.match_event); + kfree(data->onmatch.match_event_system); + kfree(data->onmatch.synth_event_name); + + for (i = 0; i < data->n_params; i++) + kfree(data->params[i]); + + if (data->onmatch.synth_event) + data->onmatch.synth_event->ref--; + + kfree(data); + + mutex_unlock(&synth_event_mutex); +} + +static void destroy_field_var(struct field_var *field_var) +{ + if (!field_var) + return; + + destroy_hist_field(field_var->var, 0); + destroy_hist_field(field_var->val, 0); + + kfree(field_var); +} + +static void destroy_field_vars(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_field_vars; i++) + destroy_field_var(hist_data->field_vars[i]); +} + +static void save_field_var(struct hist_trigger_data *hist_data, + struct field_var *field_var) +{ + hist_data->field_vars[hist_data->n_field_vars++] = field_var; + + if (field_var->val->flags & HIST_FIELD_FL_STRING) + hist_data->n_field_var_str++; +} + + +static void destroy_synth_var_refs(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_synth_var_refs; i++) + destroy_hist_field(hist_data->synth_var_refs[i], 0); +} + +static void save_synth_var_ref(struct hist_trigger_data *hist_data, + struct hist_field *var_ref) +{ + hist_data->synth_var_refs[hist_data->n_synth_var_refs++] = var_ref; + + hist_data->var_refs[hist_data->n_var_refs] = var_ref; + var_ref->var_ref_idx = hist_data->n_var_refs++; +} + +static int check_synth_field(struct synth_event *event, + struct hist_field *hist_field, + unsigned int field_pos) +{ + struct synth_field *field; + + if (field_pos >= event->n_fields) + return -EINVAL; + + field = event->fields[field_pos]; + + if (strcmp(field->type, hist_field->type) != 0) + return -EINVAL; + + return 0; +} + +static struct hist_field * +onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data, + char *system, char *event, char *var) +{ + struct hist_field *hist_field; + + var++; /* skip '$' */ + + hist_field = find_target_event_var(hist_data, system, event, var); + if (!hist_field) { + if (!system) { + system = data->onmatch.match_event_system; + event = data->onmatch.match_event; + } + + hist_field = find_event_var(hist_data, system, event, var); + } + + if (!hist_field) + hist_err_event("onmatch: Couldn't find onmatch param: $", system, event, var); + + return hist_field; +} + +static struct hist_field * +onmatch_create_field_var(struct hist_trigger_data *hist_data, + struct action_data *data, char *system, + char *event, char *var) +{ + struct hist_field *hist_field = NULL; + struct field_var *field_var; + + /* + * First try to create a field var on the target event (the + * currently being defined). This will create a variable for + * unqualified fields on the target event, or if qualified, + * target fields that have qualified names matching the target. + */ + field_var = create_target_field_var(hist_data, system, event, var); + + if (field_var && !IS_ERR(field_var)) { + save_field_var(hist_data, field_var); + hist_field = field_var->var; + } else { + field_var = NULL; + /* + * If no explicit system.event is specfied, default to + * looking for fields on the onmatch(system.event.xxx) + * event. + */ + if (!system) { + system = data->onmatch.match_event_system; + event = data->onmatch.match_event; + } + + /* + * At this point, we're looking at a field on another + * event. Because we can't modify a hist trigger on + * another event to add a variable for a field, we need + * to create a new trigger on that event and create the + * variable at the same time. + */ + hist_field = create_field_var_hist(hist_data, system, event, var); + if (IS_ERR(hist_field)) + goto free; + } + out: + return hist_field; + free: + destroy_field_var(field_var); + hist_field = NULL; + goto out; +} + +static int onmatch_create(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + struct action_data *data) +{ + char *event_name, *param, *system = NULL; + struct hist_field *hist_field, *var_ref; + unsigned int i, var_ref_idx; + unsigned int field_pos = 0; + struct synth_event *event; + int ret = 0; + + mutex_lock(&synth_event_mutex); + event = find_synth_event(data->onmatch.synth_event_name); + if (!event) { + hist_err("onmatch: Couldn't find synthetic event: ", data->onmatch.synth_event_name); + mutex_unlock(&synth_event_mutex); + return -EINVAL; + } + event->ref++; + mutex_unlock(&synth_event_mutex); + + var_ref_idx = hist_data->n_var_refs; + + for (i = 0; i < data->n_params; i++) { + char *p; + + p = param = kstrdup(data->params[i], GFP_KERNEL); + if (!param) { + ret = -ENOMEM; + goto err; + } + + system = strsep(¶m, "."); + if (!param) { + param = (char *)system; + system = event_name = NULL; + } else { + event_name = strsep(¶m, "."); + if (!param) { + kfree(p); + ret = -EINVAL; + goto err; + } + } + + if (param[0] == '$') + hist_field = onmatch_find_var(hist_data, data, system, + event_name, param); + else + hist_field = onmatch_create_field_var(hist_data, data, + system, + event_name, + param); + + if (!hist_field) { + kfree(p); + ret = -EINVAL; + goto err; + } + + if (check_synth_field(event, hist_field, field_pos) == 0) { + var_ref = create_var_ref(hist_field, system, event_name); + if (!var_ref) { + kfree(p); + ret = -ENOMEM; + goto err; + } + + save_synth_var_ref(hist_data, var_ref); + field_pos++; + kfree(p); + continue; + } + + hist_err_event("onmatch: Param type doesn't match synthetic event field type: ", + system, event_name, param); + kfree(p); + ret = -EINVAL; + goto err; + } + + if (field_pos != event->n_fields) { + hist_err("onmatch: Param count doesn't match synthetic event field count: ", event->name); + ret = -EINVAL; + goto err; + } + + data->fn = action_trace; + data->onmatch.synth_event = event; + data->onmatch.var_ref_idx = var_ref_idx; + out: + return ret; + err: + mutex_lock(&synth_event_mutex); + event->ref--; + mutex_unlock(&synth_event_mutex); + + goto out; +} + +static struct action_data *onmatch_parse(struct trace_array *tr, char *str) +{ + char *match_event, *match_event_system; + char *synth_event_name, *params; + struct action_data *data; + int ret = -EINVAL; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return ERR_PTR(-ENOMEM); + + match_event = strsep(&str, ")"); + if (!match_event || !str) { + hist_err("onmatch: Missing closing paren: ", match_event); + goto free; + } + + match_event_system = strsep(&match_event, "."); + if (!match_event) { + hist_err("onmatch: Missing subsystem for match event: ", match_event_system); + goto free; + } + + if (IS_ERR(event_file(tr, match_event_system, match_event))) { + hist_err_event("onmatch: Invalid subsystem or event name: ", + match_event_system, match_event, NULL); + goto free; + } + + data->onmatch.match_event = kstrdup(match_event, GFP_KERNEL); + if (!data->onmatch.match_event) { + ret = -ENOMEM; + goto free; + } + + data->onmatch.match_event_system = kstrdup(match_event_system, GFP_KERNEL); + if (!data->onmatch.match_event_system) { + ret = -ENOMEM; + goto free; + } + + strsep(&str, "."); + if (!str) { + hist_err("onmatch: Missing . after onmatch(): ", str); + goto free; + } + + synth_event_name = strsep(&str, "("); + if (!synth_event_name || !str) { + hist_err("onmatch: Missing opening paramlist paren: ", synth_event_name); + goto free; } - hist_data->fields[val_idx] = create_hist_field(field, flags); - if (!hist_data->fields[val_idx]) { + data->onmatch.synth_event_name = kstrdup(synth_event_name, GFP_KERNEL); + if (!data->onmatch.synth_event_name) { ret = -ENOMEM; + goto free; + } + + params = strsep(&str, ")"); + if (!params || !str || (str && strlen(str))) { + hist_err("onmatch: Missing closing paramlist paren: ", params); + goto free; + } + + ret = parse_action_params(params, data); + if (ret) + goto free; + out: + return data; + free: + onmatch_destroy(data); + data = ERR_PTR(ret); + goto out; +} + +static int create_hitcount_val(struct hist_trigger_data *hist_data) +{ + hist_data->fields[HITCOUNT_IDX] = + create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL); + if (!hist_data->fields[HITCOUNT_IDX]) + return -ENOMEM; + + hist_data->n_vals++; + hist_data->n_fields++; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return 0; +} + +static int __create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *field_str, + unsigned long flags) +{ + struct hist_field *hist_field; + int ret = 0; + + hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0); + if (IS_ERR(hist_field)) { + ret = PTR_ERR(hist_field); goto out; } + hist_data->fields[val_idx] = hist_field; + ++hist_data->n_vals; + ++hist_data->n_fields; - if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) ret = -EINVAL; out: return ret; } +static int create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *field_str) +{ + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0); +} + +static int create_var_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *expr_str) +{ + unsigned long flags = 0; + + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) + return -EINVAL; + + if (find_var(hist_data, file, var_name) && !hist_data->remove) { + hist_err("Variable already defined: ", var_name); + return -EINVAL; + } + + flags |= HIST_FIELD_FL_VAR; + hist_data->n_vars++; + if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX)) + return -EINVAL; + + return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags); +} + static int create_val_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { char *fields_str, *field_str; - unsigned int i, j; + unsigned int i, j = 1; int ret; ret = create_hitcount_val(hist_data); @@ -533,12 +3910,15 @@ static int create_val_fields(struct hist_trigger_data *hist_data, field_str = strsep(&fields_str, ","); if (!field_str) break; + if (strcmp(field_str, "hitcount") == 0) continue; + ret = create_val_field(hist_data, j++, file, field_str); if (ret) goto out; } + if (fields_str && (strcmp(fields_str, "hitcount") != 0)) ret = -EINVAL; out: @@ -551,12 +3931,13 @@ static int create_key_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, char *field_str) { - struct ftrace_event_field *field = NULL; + struct hist_field *hist_field = NULL; + unsigned long flags = 0; unsigned int key_size; int ret = 0; - if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) + if (WARN_ON(key_idx >= HIST_FIELDS_MAX)) return -EINVAL; flags |= HIST_FIELD_FL_KEY; @@ -564,57 +3945,40 @@ static int create_key_field(struct hist_trigger_data *hist_data, if (strcmp(field_str, "stacktrace") == 0) { flags |= HIST_FIELD_FL_STACKTRACE; key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH; + hist_field = create_hist_field(hist_data, NULL, flags, NULL); } else { - char *field_name = strsep(&field_str, "."); - - if (field_str) { - if (strcmp(field_str, "hex") == 0) - flags |= HIST_FIELD_FL_HEX; - else if (strcmp(field_str, "sym") == 0) - flags |= HIST_FIELD_FL_SYM; - else if (strcmp(field_str, "sym-offset") == 0) - flags |= HIST_FIELD_FL_SYM_OFFSET; - else if ((strcmp(field_str, "execname") == 0) && - (strcmp(field_name, "common_pid") == 0)) - flags |= HIST_FIELD_FL_EXECNAME; - else if (strcmp(field_str, "syscall") == 0) - flags |= HIST_FIELD_FL_SYSCALL; - else if (strcmp(field_str, "log2") == 0) - flags |= HIST_FIELD_FL_LOG2; - else { - ret = -EINVAL; - goto out; - } + hist_field = parse_expr(hist_data, file, field_str, flags, + NULL, 0); + if (IS_ERR(hist_field)) { + ret = PTR_ERR(hist_field); + goto out; } - field = trace_find_event_field(file->event_call, field_name); - if (!field || !field->size) { + if (hist_field->flags & HIST_FIELD_FL_VAR_REF) { + hist_err("Using variable references as keys not supported: ", field_str); + destroy_hist_field(hist_field, 0); ret = -EINVAL; goto out; } - if (is_string_field(field)) - key_size = MAX_FILTER_STR_VAL; - else - key_size = field->size; + key_size = hist_field->size; } - hist_data->fields[key_idx] = create_hist_field(field, flags); - if (!hist_data->fields[key_idx]) { - ret = -ENOMEM; - goto out; - } + hist_data->fields[key_idx] = hist_field; key_size = ALIGN(key_size, sizeof(u64)); hist_data->fields[key_idx]->size = key_size; hist_data->fields[key_idx]->offset = key_offset; + hist_data->key_size += key_size; + if (hist_data->key_size > HIST_KEY_SIZE_MAX) { ret = -EINVAL; goto out; } hist_data->n_keys++; + hist_data->n_fields++; if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX)) return -EINVAL; @@ -658,21 +4022,113 @@ static int create_key_fields(struct hist_trigger_data *hist_data, return ret; } +static int create_var_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, j = hist_data->n_vals; + int ret = 0; + + unsigned int n_vars = hist_data->attrs->var_defs.n_vars; + + for (i = 0; i < n_vars; i++) { + char *var_name = hist_data->attrs->var_defs.name[i]; + char *expr = hist_data->attrs->var_defs.expr[i]; + + ret = create_var_field(hist_data, j++, file, var_name, expr); + if (ret) + goto out; + } + out: + return ret; +} + +static void free_var_defs(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { + kfree(hist_data->attrs->var_defs.name[i]); + kfree(hist_data->attrs->var_defs.expr[i]); + } + + hist_data->attrs->var_defs.n_vars = 0; +} + +static int parse_var_defs(struct hist_trigger_data *hist_data) +{ + char *s, *str, *var_name, *field_str; + unsigned int i, j, n_vars = 0; + int ret = 0; + + for (i = 0; i < hist_data->attrs->n_assignments; i++) { + str = hist_data->attrs->assignment_str[i]; + for (j = 0; j < TRACING_MAP_VARS_MAX; j++) { + field_str = strsep(&str, ","); + if (!field_str) + break; + + var_name = strsep(&field_str, "="); + if (!var_name || !field_str) { + hist_err("Malformed assignment: ", var_name); + ret = -EINVAL; + goto free; + } + + if (n_vars == TRACING_MAP_VARS_MAX) { + hist_err("Too many variables defined: ", var_name); + ret = -EINVAL; + goto free; + } + + s = kstrdup(var_name, GFP_KERNEL); + if (!s) { + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.name[n_vars] = s; + + s = kstrdup(field_str, GFP_KERNEL); + if (!s) { + kfree(hist_data->attrs->var_defs.name[n_vars]); + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.expr[n_vars++] = s; + + hist_data->attrs->var_defs.n_vars = n_vars; + } + } + + return ret; + free: + free_var_defs(hist_data); + + return ret; +} + static int create_hist_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { int ret; + ret = parse_var_defs(hist_data); + if (ret) + goto out; + ret = create_val_fields(hist_data, file); if (ret) goto out; - ret = create_key_fields(hist_data, file); + ret = create_var_fields(hist_data, file); if (ret) goto out; - hist_data->n_fields = hist_data->n_vals + hist_data->n_keys; + ret = create_key_fields(hist_data, file); + if (ret) + goto out; out: + free_var_defs(hist_data); + return ret; } @@ -695,7 +4151,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) char *fields_str = hist_data->attrs->sort_key_str; struct tracing_map_sort_key *sort_key; int descending, ret = 0; - unsigned int i, j; + unsigned int i, j, k; hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */ @@ -743,12 +4199,19 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) continue; } - for (j = 1; j < hist_data->n_fields; j++) { + for (j = 1, k = 1; j < hist_data->n_fields; j++) { + unsigned int idx; + hist_field = hist_data->fields[j]; + if (hist_field->flags & HIST_FIELD_FL_VAR) + continue; + + idx = k++; + test_name = hist_field_name(hist_field, 0); if (strcmp(field_name, test_name) == 0) { - sort_key->field_idx = j; + sort_key->field_idx = idx; descending = is_descending(field_str); if (descending < 0) { ret = descending; @@ -763,16 +4226,230 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) break; } } + hist_data->n_sort_keys = i; out: return ret; } +static void destroy_actions(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->fn == action_trace) + onmatch_destroy(data); + else if (data->fn == onmax_save) + onmax_destroy(data); + else + kfree(data); + } +} + +static int parse_actions(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct action_data *data; + unsigned int i; + int ret = 0; + char *str; + + for (i = 0; i < hist_data->attrs->n_actions; i++) { + str = hist_data->attrs->action_str[i]; + + if (strncmp(str, "onmatch(", strlen("onmatch(")) == 0) { + char *action_str = str + strlen("onmatch("); + + data = onmatch_parse(tr, action_str); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + data->fn = action_trace; + } else if (strncmp(str, "onmax(", strlen("onmax(")) == 0) { + char *action_str = str + strlen("onmax("); + + data = onmax_parse(action_str); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + data->fn = onmax_save; + } else { + ret = -EINVAL; + break; + } + + hist_data->actions[hist_data->n_actions++] = data; + } + + return ret; +} + +static int create_actions(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + struct action_data *data; + unsigned int i; + int ret = 0; + + for (i = 0; i < hist_data->attrs->n_actions; i++) { + data = hist_data->actions[i]; + + if (data->fn == action_trace) { + ret = onmatch_create(hist_data, file, data); + if (ret) + return ret; + } else if (data->fn == onmax_save) { + ret = onmax_create(hist_data, data); + if (ret) + return ret; + } + } + + return ret; +} + +static void print_actions(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->fn == onmax_save) + onmax_print(m, hist_data, elt, data); + } +} + +static void print_onmax_spec(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct action_data *data) +{ + unsigned int i; + + seq_puts(m, ":onmax("); + seq_printf(m, "%s", data->onmax.var_str); + seq_printf(m, ").%s(", data->onmax.fn_name); + + for (i = 0; i < hist_data->n_max_vars; i++) { + seq_printf(m, "%s", hist_data->max_vars[i]->var->var.name); + if (i < hist_data->n_max_vars - 1) + seq_puts(m, ","); + } + seq_puts(m, ")"); +} + +static void print_onmatch_spec(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct action_data *data) +{ + unsigned int i; + + seq_printf(m, ":onmatch(%s.%s).", data->onmatch.match_event_system, + data->onmatch.match_event); + + seq_printf(m, "%s(", data->onmatch.synth_event->name); + + for (i = 0; i < data->n_params; i++) { + if (i) + seq_puts(m, ","); + seq_printf(m, "%s", data->params[i]); + } + + seq_puts(m, ")"); +} + +static bool actions_match(struct hist_trigger_data *hist_data, + struct hist_trigger_data *hist_data_test) +{ + unsigned int i, j; + + if (hist_data->n_actions != hist_data_test->n_actions) + return false; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + struct action_data *data_test = hist_data_test->actions[i]; + + if (data->fn != data_test->fn) + return false; + + if (data->n_params != data_test->n_params) + return false; + + for (j = 0; j < data->n_params; j++) { + if (strcmp(data->params[j], data_test->params[j]) != 0) + return false; + } + + if (data->fn == action_trace) { + if (strcmp(data->onmatch.synth_event_name, + data_test->onmatch.synth_event_name) != 0) + return false; + if (strcmp(data->onmatch.match_event_system, + data_test->onmatch.match_event_system) != 0) + return false; + if (strcmp(data->onmatch.match_event, + data_test->onmatch.match_event) != 0) + return false; + } else if (data->fn == onmax_save) { + if (strcmp(data->onmax.var_str, + data_test->onmax.var_str) != 0) + return false; + if (strcmp(data->onmax.fn_name, + data_test->onmax.fn_name) != 0) + return false; + } + } + + return true; +} + + +static void print_actions_spec(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->fn == action_trace) + print_onmatch_spec(m, hist_data, data); + else if (data->fn == onmax_save) + print_onmax_spec(m, hist_data, data); + } +} + +static void destroy_field_var_hists(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_field_var_hists; i++) { + kfree(hist_data->field_var_hists[i]->cmd); + kfree(hist_data->field_var_hists[i]); + } +} + static void destroy_hist_data(struct hist_trigger_data *hist_data) { + if (!hist_data) + return; + destroy_hist_trigger_attrs(hist_data->attrs); destroy_hist_fields(hist_data); tracing_map_destroy(hist_data->map); + + destroy_actions(hist_data); + destroy_field_vars(hist_data); + destroy_field_var_hists(hist_data); + destroy_synth_var_refs(hist_data); + kfree(hist_data); } @@ -781,7 +4458,7 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) struct tracing_map *map = hist_data->map; struct ftrace_event_field *field; struct hist_field *hist_field; - int i, idx; + int i, idx = 0; for_each_hist_field(i, hist_data) { hist_field = hist_data->fields[i]; @@ -792,6 +4469,9 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) if (hist_field->flags & HIST_FIELD_FL_STACKTRACE) cmp_fn = tracing_map_cmp_none; + else if (!field) + cmp_fn = tracing_map_cmp_num(hist_field->size, + hist_field->is_signed); else if (is_string_field(field)) cmp_fn = tracing_map_cmp_string; else @@ -800,36 +4480,29 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) idx = tracing_map_add_key_field(map, hist_field->offset, cmp_fn); - - } else + } else if (!(hist_field->flags & HIST_FIELD_FL_VAR)) idx = tracing_map_add_sum_field(map); if (idx < 0) return idx; - } - - return 0; -} - -static bool need_tracing_map_ops(struct hist_trigger_data *hist_data) -{ - struct hist_field *key_field; - unsigned int i; - - for_each_hist_key_field(i, hist_data) { - key_field = hist_data->fields[i]; - if (key_field->flags & HIST_FIELD_FL_EXECNAME) - return true; + if (hist_field->flags & HIST_FIELD_FL_VAR) { + idx = tracing_map_add_var(map); + if (idx < 0) + return idx; + hist_field->var.idx = idx; + hist_field->var.hist_data = hist_data; + } } - return false; + return 0; } static struct hist_trigger_data * create_hist_data(unsigned int map_bits, struct hist_trigger_attrs *attrs, - struct trace_event_file *file) + struct trace_event_file *file, + bool remove) { const struct tracing_map_ops *map_ops = NULL; struct hist_trigger_data *hist_data; @@ -840,6 +4513,12 @@ create_hist_data(unsigned int map_bits, return ERR_PTR(-ENOMEM); hist_data->attrs = attrs; + hist_data->remove = remove; + hist_data->event_file = file; + + ret = parse_actions(hist_data); + if (ret) + goto free; ret = create_hist_fields(hist_data, file); if (ret) @@ -849,8 +4528,7 @@ create_hist_data(unsigned int map_bits, if (ret) goto free; - if (need_tracing_map_ops(hist_data)) - map_ops = &hist_trigger_elt_comm_ops; + map_ops = &hist_trigger_elt_data_ops; hist_data->map = tracing_map_create(map_bits, hist_data->key_size, map_ops, hist_data); @@ -863,12 +4541,6 @@ create_hist_data(unsigned int map_bits, ret = create_tracing_map_fields(hist_data); if (ret) goto free; - - ret = tracing_map_init(hist_data->map); - if (ret) - goto free; - - hist_data->event_file = file; out: return hist_data; free: @@ -882,18 +4554,39 @@ create_hist_data(unsigned int map_bits, } static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, - struct tracing_map_elt *elt, - void *rec) + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, + u64 *var_ref_vals) { + struct hist_elt_data *elt_data; struct hist_field *hist_field; - unsigned int i; + unsigned int i, var_idx; u64 hist_val; + elt_data = elt->private_data; + elt_data->var_ref_vals = var_ref_vals; + for_each_hist_val_field(i, hist_data) { hist_field = hist_data->fields[i]; - hist_val = hist_field->fn(hist_field, rec); + hist_val = hist_field->fn(hist_field, elt, rbe, rec); + if (hist_field->flags & HIST_FIELD_FL_VAR) { + var_idx = hist_field->var.idx; + tracing_map_set_var(elt, var_idx, hist_val); + continue; + } tracing_map_update_sum(elt, i, hist_val); } + + for_each_hist_key_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_VAR) { + hist_val = hist_field->fn(hist_field, elt, rbe, rec); + var_idx = hist_field->var.idx; + tracing_map_set_var(elt, var_idx, hist_val); + } + } + + update_field_vars(hist_data, elt, rbe, rec); } static inline void add_to_key(char *compound_key, void *key, @@ -920,15 +4613,31 @@ static inline void add_to_key(char *compound_key, void *key, memcpy(compound_key + key_field->offset, key, size); } -static void event_hist_trigger(struct event_trigger_data *data, void *rec) +static void +hist_trigger_actions(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, u64 *var_ref_vals) +{ + struct action_data *data; + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + data = hist_data->actions[i]; + data->fn(hist_data, elt, rec, rbe, data, var_ref_vals); + } +} + +static void event_hist_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *rbe) { struct hist_trigger_data *hist_data = data->private_data; bool use_compound_key = (hist_data->n_keys > 1); unsigned long entries[HIST_STACKTRACE_DEPTH]; + u64 var_ref_vals[TRACING_MAP_VARS_MAX]; char compound_key[HIST_KEY_SIZE_MAX]; + struct tracing_map_elt *elt = NULL; struct stack_trace stacktrace; struct hist_field *key_field; - struct tracing_map_elt *elt; u64 field_contents; void *key = NULL; unsigned int i; @@ -949,7 +4658,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) key = entries; } else { - field_contents = key_field->fn(key_field, rec); + field_contents = key_field->fn(key_field, elt, rbe, rec); if (key_field->flags & HIST_FIELD_FL_STRING) { key = (void *)(unsigned long)field_contents; use_compound_key = true; @@ -964,9 +4673,18 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) if (use_compound_key) key = compound_key; + if (hist_data->n_var_refs && + !resolve_var_refs(hist_data, key, var_ref_vals, false)) + return; + elt = tracing_map_insert(hist_data->map, key); - if (elt) - hist_trigger_elt_update(hist_data, elt, rec); + if (!elt) + return; + + hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals); + + if (resolve_var_refs(hist_data, key, var_ref_vals, true)) + hist_trigger_actions(hist_data, elt, rec, rbe, var_ref_vals); } static void hist_trigger_stacktrace_print(struct seq_file *m, @@ -1023,7 +4741,13 @@ hist_trigger_entry_print(struct seq_file *m, seq_printf(m, "%s: [%llx] %-55s", field_name, uval, str); } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) { - char *comm = elt->private_data; + struct hist_elt_data *elt_data = elt->private_data; + char *comm; + + if (WARN_ON_ONCE(!elt_data)) + return; + + comm = elt_data->comm; uval = *(u64 *)(key + key_field->offset); seq_printf(m, "%s: %-16s[%10llu]", field_name, @@ -1067,6 +4791,10 @@ hist_trigger_entry_print(struct seq_file *m, for (i = 1; i < hist_data->n_vals; i++) { field_name = hist_field_name(hist_data->fields[i], 0); + if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR || + hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR) + continue; + if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { seq_printf(m, " %s: %10llx", field_name, tracing_map_read_sum(elt, i)); @@ -1076,6 +4804,8 @@ hist_trigger_entry_print(struct seq_file *m, } } + print_actions(m, hist_data, elt); + seq_puts(m, "\n"); } @@ -1144,6 +4874,11 @@ static int hist_show(struct seq_file *m, void *v) hist_trigger_show(m, data, n++); } + if (have_hist_err()) { + seq_printf(m, "\nERROR: %s\n", hist_err_str); + seq_printf(m, " Last command: %s\n", last_hist_cmd); + } + out_unlock: mutex_unlock(&event_mutex); @@ -1162,37 +4897,22 @@ const struct file_operations event_hist_fops = { .release = single_release, }; -static const char *get_hist_field_flags(struct hist_field *hist_field) -{ - const char *flags_str = NULL; - - if (hist_field->flags & HIST_FIELD_FL_HEX) - flags_str = "hex"; - else if (hist_field->flags & HIST_FIELD_FL_SYM) - flags_str = "sym"; - else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) - flags_str = "sym-offset"; - else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) - flags_str = "execname"; - else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) - flags_str = "syscall"; - else if (hist_field->flags & HIST_FIELD_FL_LOG2) - flags_str = "log2"; - - return flags_str; -} - static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) { const char *field_name = hist_field_name(hist_field, 0); - seq_printf(m, "%s", field_name); - if (hist_field->flags) { - const char *flags_str = get_hist_field_flags(hist_field); - - if (flags_str) - seq_printf(m, ".%s", flags_str); - } + if (hist_field->var.name) + seq_printf(m, "%s=", hist_field->var.name); + + if (hist_field->flags & HIST_FIELD_FL_CPU) + seq_puts(m, "cpu"); + else if (field_name) { + if (hist_field->flags & HIST_FIELD_FL_VAR_REF || + hist_field->flags & HIST_FIELD_FL_ALIAS) + seq_putc(m, '$'); + seq_printf(m, "%s", field_name); + } else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP) + seq_puts(m, "common_timestamp"); } static int event_hist_trigger_print(struct seq_file *m, @@ -1200,7 +4920,8 @@ static int event_hist_trigger_print(struct seq_file *m, struct event_trigger_data *data) { struct hist_trigger_data *hist_data = data->private_data; - struct hist_field *key_field; + struct hist_field *field; + bool have_var = false; unsigned int i; seq_puts(m, "hist:"); @@ -1211,25 +4932,47 @@ static int event_hist_trigger_print(struct seq_file *m, seq_puts(m, "keys="); for_each_hist_key_field(i, hist_data) { - key_field = hist_data->fields[i]; + field = hist_data->fields[i]; if (i > hist_data->n_vals) seq_puts(m, ","); - if (key_field->flags & HIST_FIELD_FL_STACKTRACE) + if (field->flags & HIST_FIELD_FL_STACKTRACE) seq_puts(m, "stacktrace"); else - hist_field_print(m, key_field); + hist_field_print(m, field); } seq_puts(m, ":vals="); for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + if (field->flags & HIST_FIELD_FL_VAR) { + have_var = true; + continue; + } + if (i == HITCOUNT_IDX) seq_puts(m, "hitcount"); else { seq_puts(m, ","); - hist_field_print(m, hist_data->fields[i]); + hist_field_print(m, field); + } + } + + if (have_var) { + unsigned int n = 0; + + seq_puts(m, ":"); + + for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + + if (field->flags & HIST_FIELD_FL_VAR) { + if (n++) + seq_puts(m, ","); + hist_field_print(m, field); + } } } @@ -1237,28 +4980,36 @@ static int event_hist_trigger_print(struct seq_file *m, for (i = 0; i < hist_data->n_sort_keys; i++) { struct tracing_map_sort_key *sort_key; + unsigned int idx, first_key_idx; + + /* skip VAR vals */ + first_key_idx = hist_data->n_vals - hist_data->n_vars; sort_key = &hist_data->sort_keys[i]; + idx = sort_key->field_idx; + + if (WARN_ON(idx >= HIST_FIELDS_MAX)) + return -EINVAL; if (i > 0) seq_puts(m, ","); - if (sort_key->field_idx == HITCOUNT_IDX) + if (idx == HITCOUNT_IDX) seq_puts(m, "hitcount"); else { - unsigned int idx = sort_key->field_idx; - - if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX)) - return -EINVAL; - + if (idx >= first_key_idx) + idx += hist_data->n_vars; hist_field_print(m, hist_data->fields[idx]); } if (sort_key->descending) seq_puts(m, ".descending"); } - seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits)); + if (hist_data->enable_timestamps) + seq_printf(m, ":clock=%s", hist_data->attrs->clock); + + print_actions_spec(m, hist_data); if (data->filter_str) seq_printf(m, " if %s", data->filter_str); @@ -1286,6 +5037,21 @@ static int event_hist_trigger_init(struct event_trigger_ops *ops, return 0; } +static void unregister_field_var_hists(struct hist_trigger_data *hist_data) +{ + struct trace_event_file *file; + unsigned int i; + char *cmd; + int ret; + + for (i = 0; i < hist_data->n_field_var_hists; i++) { + file = hist_data->field_var_hists[i]->hist_data->event_file; + cmd = hist_data->field_var_hists[i]->cmd; + ret = event_hist_trigger_func(&trigger_hist_cmd, file, + "!hist", "hist", cmd); + } +} + static void event_hist_trigger_free(struct event_trigger_ops *ops, struct event_trigger_data *data) { @@ -1298,7 +5064,13 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops, if (!data->ref) { if (data->name) del_named_trigger(data); + trigger_data_free(data); + + remove_hist_vars(hist_data); + + unregister_field_var_hists(hist_data); + destroy_hist_data(hist_data); } } @@ -1425,6 +5197,15 @@ static bool hist_trigger_match(struct event_trigger_data *data, return false; if (key_field->offset != key_field_test->offset) return false; + if (key_field->size != key_field_test->size) + return false; + if (key_field->is_signed != key_field_test->is_signed) + return false; + if (!!key_field->var.name != !!key_field_test->var.name) + return false; + if (key_field->var.name && + strcmp(key_field->var.name, key_field_test->var.name) != 0) + return false; } for (i = 0; i < hist_data->n_sort_keys; i++) { @@ -1440,6 +5221,9 @@ static bool hist_trigger_match(struct event_trigger_data *data, (strcmp(data->filter_str, data_test->filter_str) != 0)) return false; + if (!actions_match(hist_data, hist_data_test)) + return false; + return true; } @@ -1456,6 +5240,7 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, if (named_data) { if (!hist_trigger_match(data, named_data, named_data, true)) { + hist_err("Named hist trigger doesn't match existing named trigger (includes variables): ", hist_data->attrs->name); ret = -EINVAL; goto out; } @@ -1475,13 +5260,16 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, test->paused = false; else if (hist_data->attrs->clear) hist_clear(test); - else + else { + hist_err("Hist trigger already exists", NULL); ret = -EEXIST; + } goto out; } } new: if (hist_data->attrs->cont || hist_data->attrs->clear) { + hist_err("Can't clear or continue a nonexistent hist trigger", NULL); ret = -ENOENT; goto out; } @@ -1490,7 +5278,6 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, data->paused = true; if (named_data) { - destroy_hist_data(data->private_data); data->private_data = named_data->private_data; set_named_trigger_data(data, named_data); data->ops = &event_hist_trigger_named_ops; @@ -1502,8 +5289,32 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, goto out; } - list_add_rcu(&data->list, &file->triggers); + if (hist_data->enable_timestamps) { + char *clock = hist_data->attrs->clock; + + ret = tracing_set_clock(file->tr, hist_data->attrs->clock); + if (ret) { + hist_err("Couldn't set trace_clock: ", clock); + goto out; + } + + tracing_set_time_stamp_abs(file->tr, true); + } + + if (named_data) + destroy_hist_data(hist_data); + ret++; + out: + return ret; +} + +static int hist_trigger_enable(struct event_trigger_data *data, + struct trace_event_file *file) +{ + int ret = 0; + + list_add_tail_rcu(&data->list, &file->triggers); update_cond_flag(file); @@ -1512,10 +5323,55 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, update_cond_flag(file); ret--; } - out: + return ret; } +static bool have_hist_trigger_match(struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + bool match = false; + + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (hist_trigger_match(data, test, named_data, false)) { + match = true; + break; + } + } + } + + return match; +} + +static bool hist_trigger_check_refs(struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test, named_data, false)) + continue; + hist_data = test->private_data; + if (check_var_refs(hist_data)) + return true; + break; + } + } + + return false; +} + static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) @@ -1541,17 +5397,55 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, if (unregistered && test->ops->free) test->ops->free(test->ops, test); + + if (hist_data->enable_timestamps) { + if (!hist_data->remove || unregistered) + tracing_set_time_stamp_abs(file->tr, false); + } +} + +static bool hist_file_check_refs(struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; + if (check_var_refs(hist_data)) + return true; + } + } + + return false; } static void hist_unreg_all(struct trace_event_file *file) { struct event_trigger_data *test, *n; + struct hist_trigger_data *hist_data; + struct synth_event *se; + const char *se_name; + + if (hist_file_check_refs(file)) + return; list_for_each_entry_safe(test, n, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; list_del_rcu(&test->list); trace_event_trigger_enable_disable(file, 0); + + mutex_lock(&synth_event_mutex); + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref--; + mutex_unlock(&synth_event_mutex); + update_cond_flag(file); + if (hist_data->enable_timestamps) + tracing_set_time_stamp_abs(file->tr, false); if (test->ops->free) test->ops->free(test->ops, test); } @@ -1567,16 +5461,54 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, struct hist_trigger_attrs *attrs; struct event_trigger_ops *trigger_ops; struct hist_trigger_data *hist_data; - char *trigger; + struct synth_event *se; + const char *se_name; + bool remove = false; + char *trigger, *p; int ret = 0; + if (glob && strlen(glob)) { + last_cmd_set(param); + hist_err_clear(); + } + if (!param) return -EINVAL; - /* separate the trigger from the filter (k:v [if filter]) */ - trigger = strsep(¶m, " \t"); - if (!trigger) - return -EINVAL; + if (glob[0] == '!') + remove = true; + + /* + * separate the trigger from the filter (k:v [if filter]) + * allowing for whitespace in the trigger + */ + p = trigger = param; + do { + p = strstr(p, "if"); + if (!p) + break; + if (p == param) + return -EINVAL; + if (*(p - 1) != ' ' && *(p - 1) != '\t') { + p++; + continue; + } + if (p >= param + strlen(param) - strlen("if") - 1) + return -EINVAL; + if (*(p + strlen("if")) != ' ' && *(p + strlen("if")) != '\t') { + p++; + continue; + } + break; + } while (p); + + if (!p) + param = NULL; + else { + *(p - 1) = '\0'; + param = strstrip(p); + trigger = strstrip(trigger); + } attrs = parse_hist_trigger_attrs(trigger); if (IS_ERR(attrs)) @@ -1585,7 +5517,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, if (attrs->map_bits) hist_trigger_bits = attrs->map_bits; - hist_data = create_hist_data(hist_trigger_bits, attrs, file); + hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove); if (IS_ERR(hist_data)) { destroy_hist_trigger_attrs(attrs); return PTR_ERR(hist_data); @@ -1593,10 +5525,11 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); - ret = -ENOMEM; trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); - if (!trigger_data) + if (!trigger_data) { + ret = -ENOMEM; goto out_free; + } trigger_data->count = -1; trigger_data->ops = trigger_ops; @@ -1614,8 +5547,24 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, goto out_free; } - if (glob[0] == '!') { + if (remove) { + if (!have_hist_trigger_match(trigger_data, file)) + goto out_free; + + if (hist_trigger_check_refs(trigger_data, file)) { + ret = -EBUSY; + goto out_free; + } + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + + mutex_lock(&synth_event_mutex); + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref--; + mutex_unlock(&synth_event_mutex); + ret = 0; goto out_free; } @@ -1632,14 +5581,47 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, goto out_free; } else if (ret < 0) goto out_free; + + if (get_named_trigger_data(trigger_data)) + goto enable; + + if (has_hist_vars(hist_data)) + save_hist_vars(hist_data); + + ret = create_actions(hist_data, file); + if (ret) + goto out_unreg; + + ret = tracing_map_init(hist_data->map); + if (ret) + goto out_unreg; +enable: + ret = hist_trigger_enable(trigger_data, file); + if (ret) + goto out_unreg; + + mutex_lock(&synth_event_mutex); + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref++; + mutex_unlock(&synth_event_mutex); + /* Just return zero, not the number of registered triggers */ ret = 0; out: + if (ret == 0) + hist_err_clear(); + return ret; + out_unreg: + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); out_free: if (cmd_ops->set_filter) cmd_ops->set_filter(NULL, trigger_data, NULL); + remove_hist_vars(hist_data); + kfree(trigger_data); destroy_hist_data(hist_data); @@ -1669,7 +5651,8 @@ __init int register_trigger_hist_cmd(void) } static void -hist_enable_trigger(struct event_trigger_data *data, void *rec) +hist_enable_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { struct enable_trigger_data *enable_data = data->private_data; struct event_trigger_data *test; @@ -1685,7 +5668,8 @@ hist_enable_trigger(struct event_trigger_data *data, void *rec) } static void -hist_enable_count_trigger(struct event_trigger_data *data, void *rec) +hist_enable_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (!data->count) return; @@ -1693,7 +5677,7 @@ hist_enable_count_trigger(struct event_trigger_data *data, void *rec) if (data->count != -1) (data->count)--; - hist_enable_trigger(data, rec); + hist_enable_trigger(data, rec, event); } static struct event_trigger_ops hist_enable_trigger_ops = { @@ -1798,3 +5782,31 @@ __init int register_trigger_hist_enable_disable_cmds(void) return ret; } + +static __init int trace_events_hist_init(void) +{ + struct dentry *entry = NULL; + struct dentry *d_tracer; + int err = 0; + + d_tracer = tracing_init_dentry(); + if (IS_ERR(d_tracer)) { + err = PTR_ERR(d_tracer); + goto err; + } + + entry = tracefs_create_file("synthetic_events", 0644, d_tracer, + NULL, &synth_events_fops); + if (!entry) { + err = -ENODEV; + goto err; + } + + return err; + err: + pr_warn("Could not create tracefs 'synthetic_events' entry\n"); + + return err; +} + +fs_initcall(trace_events_hist_init); diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 87411482a46f..d251cabcf69a 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -63,7 +63,8 @@ void trigger_data_free(struct event_trigger_data *data) * any trigger that should be deferred, ETT_NONE if nothing to defer. */ enum event_trigger_type -event_triggers_call(struct trace_event_file *file, void *rec) +event_triggers_call(struct trace_event_file *file, void *rec, + struct ring_buffer_event *event) { struct event_trigger_data *data; enum event_trigger_type tt = ETT_NONE; @@ -76,7 +77,7 @@ event_triggers_call(struct trace_event_file *file, void *rec) if (data->paused) continue; if (!rec) { - data->ops->func(data, rec); + data->ops->func(data, rec, event); continue; } filter = rcu_dereference_sched(data->filter); @@ -86,7 +87,7 @@ event_triggers_call(struct trace_event_file *file, void *rec) tt |= data->cmd_ops->trigger_type; continue; } - data->ops->func(data, rec); + data->ops->func(data, rec, event); } return tt; } @@ -108,7 +109,7 @@ EXPORT_SYMBOL_GPL(event_triggers_call); void event_triggers_post_call(struct trace_event_file *file, enum event_trigger_type tt, - void *rec) + void *rec, struct ring_buffer_event *event) { struct event_trigger_data *data; @@ -116,7 +117,7 @@ event_triggers_post_call(struct trace_event_file *file, if (data->paused) continue; if (data->cmd_ops->trigger_type & tt) - data->ops->func(data, rec); + data->ops->func(data, rec, event); } } EXPORT_SYMBOL_GPL(event_triggers_post_call); @@ -908,8 +909,15 @@ void set_named_trigger_data(struct event_trigger_data *data, data->named_data = named_data; } +struct event_trigger_data * +get_named_trigger_data(struct event_trigger_data *data) +{ + return data->named_data; +} + static void -traceon_trigger(struct event_trigger_data *data, void *rec) +traceon_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (tracing_is_on()) return; @@ -918,7 +926,8 @@ traceon_trigger(struct event_trigger_data *data, void *rec) } static void -traceon_count_trigger(struct event_trigger_data *data, void *rec) +traceon_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (tracing_is_on()) return; @@ -933,7 +942,8 @@ traceon_count_trigger(struct event_trigger_data *data, void *rec) } static void -traceoff_trigger(struct event_trigger_data *data, void *rec) +traceoff_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (!tracing_is_on()) return; @@ -942,7 +952,8 @@ traceoff_trigger(struct event_trigger_data *data, void *rec) } static void -traceoff_count_trigger(struct event_trigger_data *data, void *rec) +traceoff_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (!tracing_is_on()) return; @@ -1039,13 +1050,15 @@ static struct event_command trigger_traceoff_cmd = { #ifdef CONFIG_TRACER_SNAPSHOT static void -snapshot_trigger(struct event_trigger_data *data, void *rec) +snapshot_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { tracing_snapshot(); } static void -snapshot_count_trigger(struct event_trigger_data *data, void *rec) +snapshot_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (!data->count) return; @@ -1053,7 +1066,7 @@ snapshot_count_trigger(struct event_trigger_data *data, void *rec) if (data->count != -1) (data->count)--; - snapshot_trigger(data, rec); + snapshot_trigger(data, rec, event); } static int @@ -1141,13 +1154,15 @@ static __init int register_trigger_snapshot_cmd(void) { return 0; } #endif static void -stacktrace_trigger(struct event_trigger_data *data, void *rec) +stacktrace_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { trace_dump_stack(STACK_SKIP); } static void -stacktrace_count_trigger(struct event_trigger_data *data, void *rec) +stacktrace_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { if (!data->count) return; @@ -1155,7 +1170,7 @@ stacktrace_count_trigger(struct event_trigger_data *data, void *rec) if (data->count != -1) (data->count)--; - stacktrace_trigger(data, rec); + stacktrace_trigger(data, rec, event); } static int @@ -1217,7 +1232,8 @@ static __init void unregister_trigger_traceon_traceoff_cmds(void) } static void -event_enable_trigger(struct event_trigger_data *data, void *rec) +event_enable_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { struct enable_trigger_data *enable_data = data->private_data; @@ -1228,7 +1244,8 @@ event_enable_trigger(struct event_trigger_data *data, void *rec) } static void -event_enable_count_trigger(struct event_trigger_data *data, void *rec) +event_enable_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) { struct enable_trigger_data *enable_data = data->private_data; @@ -1242,7 +1259,7 @@ event_enable_count_trigger(struct event_trigger_data *data, void *rec) if (data->count != -1) (data->count)--; - event_enable_trigger(data, rec); + event_enable_trigger(data, rec, event); } int event_enable_trigger_print(struct seq_file *m, diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index 07e75344725b..5cadb1b8b5fe 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -66,6 +66,73 @@ u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i) return (u64)atomic64_read(&elt->fields[i].sum); } +/** + * tracing_map_set_var - Assign a tracing_map_elt's variable field + * @elt: The tracing_map_elt + * @i: The index of the given variable associated with the tracing_map_elt + * @n: The value to assign + * + * Assign n to variable i associated with the specified tracing_map_elt + * instance. The index i is the index returned by the call to + * tracing_map_add_var() when the tracing map was set up. + */ +void tracing_map_set_var(struct tracing_map_elt *elt, unsigned int i, u64 n) +{ + atomic64_set(&elt->vars[i], n); + elt->var_set[i] = true; +} + +/** + * tracing_map_var_set - Return whether or not a variable has been set + * @elt: The tracing_map_elt + * @i: The index of the given variable associated with the tracing_map_elt + * + * Return true if the variable has been set, false otherwise. The + * index i is the index returned by the call to tracing_map_add_var() + * when the tracing map was set up. + */ +bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i) +{ + return elt->var_set[i]; +} + +/** + * tracing_map_read_var - Return the value of a tracing_map_elt's variable field + * @elt: The tracing_map_elt + * @i: The index of the given variable associated with the tracing_map_elt + * + * Retrieve the value of the variable i associated with the specified + * tracing_map_elt instance. The index i is the index returned by the + * call to tracing_map_add_var() when the tracing map was set + * up. + * + * Return: The variable value associated with field i for elt. + */ +u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i) +{ + return (u64)atomic64_read(&elt->vars[i]); +} + +/** + * tracing_map_read_var_once - Return and reset a tracing_map_elt's variable field + * @elt: The tracing_map_elt + * @i: The index of the given variable associated with the tracing_map_elt + * + * Retrieve the value of the variable i associated with the specified + * tracing_map_elt instance, and reset the variable to the 'not set' + * state. The index i is the index returned by the call to + * tracing_map_add_var() when the tracing map was set up. The reset + * essentially makes the variable a read-once variable if it's only + * accessed using this function. + * + * Return: The variable value associated with field i for elt. + */ +u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i) +{ + elt->var_set[i] = false; + return (u64)atomic64_read(&elt->vars[i]); +} + int tracing_map_cmp_string(void *val_a, void *val_b) { char *a = val_a; @@ -171,6 +238,28 @@ int tracing_map_add_sum_field(struct tracing_map *map) } /** + * tracing_map_add_var - Add a field describing a tracing_map var + * @map: The tracing_map + * + * Add a var to the map and return the index identifying it in the map + * and associated tracing_map_elts. This is the index used for + * instance to update a var for a particular tracing_map_elt using + * tracing_map_update_var() or reading it via tracing_map_read_var(). + * + * Return: The index identifying the var in the map and associated + * tracing_map_elts, or -EINVAL on error. + */ +int tracing_map_add_var(struct tracing_map *map) +{ + int ret = -EINVAL; + + if (map->n_vars < TRACING_MAP_VARS_MAX) + ret = map->n_vars++; + + return ret; +} + +/** * tracing_map_add_key_field - Add a field describing a tracing_map key * @map: The tracing_map * @offset: The offset within the key @@ -280,6 +369,11 @@ static void tracing_map_elt_clear(struct tracing_map_elt *elt) if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64) atomic64_set(&elt->fields[i].sum, 0); + for (i = 0; i < elt->map->n_vars; i++) { + atomic64_set(&elt->vars[i], 0); + elt->var_set[i] = false; + } + if (elt->map->ops && elt->map->ops->elt_clear) elt->map->ops->elt_clear(elt); } @@ -306,6 +400,8 @@ static void tracing_map_elt_free(struct tracing_map_elt *elt) if (elt->map->ops && elt->map->ops->elt_free) elt->map->ops->elt_free(elt); kfree(elt->fields); + kfree(elt->vars); + kfree(elt->var_set); kfree(elt->key); kfree(elt); } @@ -333,6 +429,18 @@ static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map) goto free; } + elt->vars = kcalloc(map->n_vars, sizeof(*elt->vars), GFP_KERNEL); + if (!elt->vars) { + err = -ENOMEM; + goto free; + } + + elt->var_set = kcalloc(map->n_vars, sizeof(*elt->var_set), GFP_KERNEL); + if (!elt->var_set) { + err = -ENOMEM; + goto free; + } + tracing_map_elt_init_fields(elt); if (map->ops && map->ops->elt_alloc) { @@ -414,7 +522,9 @@ static inline struct tracing_map_elt * __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only) { u32 idx, key_hash, test_key; + int dup_try = 0; struct tracing_map_entry *entry; + struct tracing_map_elt *val; key_hash = jhash(key, map->key_size, 0); if (key_hash == 0) @@ -426,11 +536,33 @@ __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only) entry = TRACING_MAP_ENTRY(map->map, idx); test_key = entry->key; - if (test_key && test_key == key_hash && entry->val && - keys_match(key, entry->val->key, map->key_size)) { - if (!lookup_only) - atomic64_inc(&map->hits); - return entry->val; + if (test_key && test_key == key_hash) { + val = READ_ONCE(entry->val); + if (val && + keys_match(key, val->key, map->key_size)) { + if (!lookup_only) + atomic64_inc(&map->hits); + return val; + } else if (unlikely(!val)) { + /* + * The key is present. But, val (pointer to elt + * struct) is still NULL. which means some other + * thread is in the process of inserting an + * element. + * + * On top of that, it's key_hash is same as the + * one being inserted right now. So, it's + * possible that the element has the same + * key as well. + */ + + dup_try++; + if (dup_try > map->map_size) { + atomic64_inc(&map->drops); + break; + } + continue; + } } if (!test_key) { @@ -452,6 +584,13 @@ __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only) atomic64_inc(&map->hits); return entry->val; + } else { + /* + * cmpxchg() failed. Loop around once + * more to check what key was inserted. + */ + dup_try++; + continue; } } @@ -816,67 +955,15 @@ create_sort_entry(void *key, struct tracing_map_elt *elt) return sort_entry; } -static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt) -{ - struct tracing_map_elt *dup_elt; - unsigned int i; - - dup_elt = tracing_map_elt_alloc(elt->map); - if (IS_ERR(dup_elt)) - return NULL; - - if (elt->map->ops && elt->map->ops->elt_copy) - elt->map->ops->elt_copy(dup_elt, elt); - - dup_elt->private_data = elt->private_data; - memcpy(dup_elt->key, elt->key, elt->map->key_size); - - for (i = 0; i < elt->map->n_fields; i++) { - atomic64_set(&dup_elt->fields[i].sum, - atomic64_read(&elt->fields[i].sum)); - dup_elt->fields[i].cmp_fn = elt->fields[i].cmp_fn; - } - - return dup_elt; -} - -static int merge_dup(struct tracing_map_sort_entry **sort_entries, - unsigned int target, unsigned int dup) -{ - struct tracing_map_elt *target_elt, *elt; - bool first_dup = (target - dup) == 1; - int i; - - if (first_dup) { - elt = sort_entries[target]->elt; - target_elt = copy_elt(elt); - if (!target_elt) - return -ENOMEM; - sort_entries[target]->elt = target_elt; - sort_entries[target]->elt_copied = true; - } else - target_elt = sort_entries[target]->elt; - - elt = sort_entries[dup]->elt; - - for (i = 0; i < elt->map->n_fields; i++) - atomic64_add(atomic64_read(&elt->fields[i].sum), - &target_elt->fields[i].sum); - - sort_entries[dup]->dup = true; - - return 0; -} - -static int merge_dups(struct tracing_map_sort_entry **sort_entries, +static void detect_dups(struct tracing_map_sort_entry **sort_entries, int n_entries, unsigned int key_size) { unsigned int dups = 0, total_dups = 0; - int err, i, j; + int i; void *key; if (n_entries < 2) - return total_dups; + return; sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *), (int (*)(const void *, const void *))cmp_entries_dup, NULL); @@ -885,30 +972,14 @@ static int merge_dups(struct tracing_map_sort_entry **sort_entries, for (i = 1; i < n_entries; i++) { if (!memcmp(sort_entries[i]->key, key, key_size)) { dups++; total_dups++; - err = merge_dup(sort_entries, i - dups, i); - if (err) - return err; continue; } key = sort_entries[i]->key; dups = 0; } - if (!total_dups) - return total_dups; - - for (i = 0, j = 0; i < n_entries; i++) { - if (!sort_entries[i]->dup) { - sort_entries[j] = sort_entries[i]; - if (j++ != i) - sort_entries[i] = NULL; - } else { - destroy_sort_entry(sort_entries[i]); - sort_entries[i] = NULL; - } - } - - return total_dups; + WARN_ONCE(total_dups > 0, + "Duplicates detected: %d\n", total_dups); } static bool is_key(struct tracing_map *map, unsigned int field_idx) @@ -1034,10 +1105,7 @@ int tracing_map_sort_entries(struct tracing_map *map, return 1; } - ret = merge_dups(entries, n_entries, map->key_size); - if (ret < 0) - goto free; - n_entries -= ret; + detect_dups(entries, n_entries, map->key_size); if (is_key(map, sort_keys[0].field_idx)) cmp_entries_fn = cmp_entries_key; diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h index 5b5bbf8ae550..053eb92b2d31 100644 --- a/kernel/trace/tracing_map.h +++ b/kernel/trace/tracing_map.h @@ -10,6 +10,7 @@ #define TRACING_MAP_VALS_MAX 3 #define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \ TRACING_MAP_VALS_MAX) +#define TRACING_MAP_VARS_MAX 16 #define TRACING_MAP_SORT_KEYS_MAX 2 typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b); @@ -137,6 +138,8 @@ struct tracing_map_field { struct tracing_map_elt { struct tracing_map *map; struct tracing_map_field *fields; + atomic64_t *vars; + bool *var_set; void *key; void *private_data; }; @@ -192,6 +195,7 @@ struct tracing_map { int key_idx[TRACING_MAP_KEYS_MAX]; unsigned int n_keys; struct tracing_map_sort_key sort_key; + unsigned int n_vars; atomic64_t hits; atomic64_t drops; }; @@ -215,11 +219,6 @@ struct tracing_map { * Element allocation occurs before tracing begins, when the * tracing_map_init() call is made by client code. * - * @elt_copy: At certain points in the lifetime of an element, it may - * need to be copied. The copy should include a copy of the - * client-allocated data, which can be copied into the 'to' - * element from the 'from' element. - * * @elt_free: When a tracing_map_elt is freed, this function is called * and allows client-allocated per-element data to be freed. * @@ -233,8 +232,6 @@ struct tracing_map { */ struct tracing_map_ops { int (*elt_alloc)(struct tracing_map_elt *elt); - void (*elt_copy)(struct tracing_map_elt *to, - struct tracing_map_elt *from); void (*elt_free)(struct tracing_map_elt *elt); void (*elt_clear)(struct tracing_map_elt *elt); void (*elt_init)(struct tracing_map_elt *elt); @@ -248,6 +245,7 @@ tracing_map_create(unsigned int map_bits, extern int tracing_map_init(struct tracing_map *map); extern int tracing_map_add_sum_field(struct tracing_map *map); +extern int tracing_map_add_var(struct tracing_map *map); extern int tracing_map_add_key_field(struct tracing_map *map, unsigned int offset, tracing_map_cmp_fn_t cmp_fn); @@ -267,7 +265,13 @@ extern int tracing_map_cmp_none(void *val_a, void *val_b); extern void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n); +extern void tracing_map_set_var(struct tracing_map_elt *elt, + unsigned int i, u64 n); +extern bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i); extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i); +extern u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i); +extern u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i); + extern void tracing_map_set_field_descr(struct tracing_map *map, unsigned int i, unsigned int key_offset, diff --git a/lib/vsprintf.c b/lib/vsprintf.c index d7a708f82559..89f8a4a4b770 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2591,6 +2591,8 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) case 's': case 'F': case 'f': + case 'x': + case 'K': save_arg(void *); break; default: @@ -2765,6 +2767,8 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) case 's': case 'F': case 'f': + case 'x': + case 'K': process = true; break; default: diff --git a/security/security.c b/security/security.c index d2a84cda7e8d..7bc2fde023a7 100644 --- a/security/security.c +++ b/security/security.c @@ -30,6 +30,8 @@ #include <linux/string.h> #include <net/flow.h> +#include <trace/events/initcall.h> + #define MAX_LSM_EVM_XATTR 2 /* Maximum number of letters for an LSM name string */ @@ -45,10 +47,14 @@ static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = static void __init do_security_initcalls(void) { + int ret; initcall_t *call; call = __security_initcall_start; + trace_initcall_level("security"); while (call < __security_initcall_end) { - (*call) (); + trace_initcall_start((*call)); + ret = (*call) (); + trace_initcall_finish((*call), ret); call++; } } diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions index df3dd7fe5f9b..2a4f16fc9819 100644 --- a/tools/testing/selftests/ftrace/test.d/functions +++ b/tools/testing/selftests/ftrace/test.d/functions @@ -59,6 +59,13 @@ disable_events() { echo 0 > events/enable } +clear_synthetic_events() { # reset all current synthetic events + grep -v ^# synthetic_events | + while read line; do + echo "!$line" >> synthetic_events + done +} + initialize_ftrace() { # Reset ftrace to initial-state # As the initial state, ftrace will be set to nop tracer, # no events, no triggers, no filters, no function filters, diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc new file mode 100644 index 000000000000..786dce7e48be --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc @@ -0,0 +1,39 @@ +#!/bin/sh +# description: event trigger - test extended error support + + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +echo "Test extended error support" +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger &>/dev/null +if ! grep -q "ERROR:" events/sched/sched_wakeup/hist; then + fail "Failed to generate extended error in histogram" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc new file mode 100644 index 000000000000..7fd5b4a8f060 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc @@ -0,0 +1,54 @@ +#!/bin/sh +# description: event trigger - test field variable support + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +clear_synthetic_events +reset_tracer +do_reset + +echo "Test field variable support" + +echo 'wakeup_latency u64 lat; pid_t pid; int prio; char comm[16]' > synthetic_events +echo 'hist:keys=comm:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_waking/trigger +echo 'hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' > events/sched/sched_switch/trigger +echo 'hist:keys=pid,prio,comm:vals=lat:sort=pid,prio' > events/synthetic/wakeup_latency/trigger + +ping localhost -c 3 +if ! grep -q "ping" events/synthetic/wakeup_latency/hist; then + fail "Failed to create inter-event histogram" +fi + +if ! grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then + fail "Failed to create histogram with field variable" +fi + +echo '!hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger + +if grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then + fail "Failed to remove histogram with field variable" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc new file mode 100644 index 000000000000..c93dbe38b5df --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc @@ -0,0 +1,58 @@ +#!/bin/sh +# description: event trigger - test inter-event combined histogram trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +reset_tracer +do_reset +clear_synthetic_events + +echo "Test create synthetic event" + +echo 'waking_latency u64 lat pid_t pid' > synthetic_events +if [ ! -d events/synthetic/waking_latency ]; then + fail "Failed to create waking_latency synthetic event" +fi + +echo "Test combined histogram" + +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_waking/trigger +echo 'hist:keys=pid:waking_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).waking_latency($waking_lat,pid) if comm=="ping"' > events/sched/sched_wakeup/trigger +echo 'hist:keys=pid,lat:sort=pid,lat' > events/synthetic/waking_latency/trigger + +echo 'wakeup_latency u64 lat pid_t pid' >> synthetic_events +echo 'hist:keys=pid:ts1=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger +echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts1:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid) if next_comm=="ping"' > events/sched/sched_switch/trigger + +echo 'waking+wakeup_latency u64 lat; pid_t pid' >> synthetic_events +echo 'hist:keys=pid,lat:sort=pid,lat:ww_lat=$waking_lat+$wakeup_lat:onmatch(synthetic.wakeup_latency).waking+wakeup_latency($ww_lat,pid)' >> events/synthetic/wakeup_latency/trigger +echo 'hist:keys=pid,lat:sort=pid,lat' >> events/synthetic/waking+wakeup_latency/trigger + +ping localhost -c 3 +if ! grep -q "pid:" events/synthetic/waking+wakeup_latency/hist; then + fail "Failed to create combined histogram" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc new file mode 100644 index 000000000000..e84e7d048566 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc @@ -0,0 +1,50 @@ +#!/bin/sh +# description: event trigger - test inter-event histogram trigger onmatch action + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +clear_synthetic_events +reset_tracer +do_reset + +echo "Test create synthetic event" + +echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +if [ ! -d events/synthetic/wakeup_latency ]; then + fail "Failed to create wakeup_latency synthetic event" +fi + +echo "Test create histogram for synthetic event" +echo "Test histogram variables,simple expression support and onmatch action" + +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger +echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid,next_comm) if next_comm=="ping"' > events/sched/sched_switch/trigger +echo 'hist:keys=comm,pid,lat:wakeup_lat=lat:sort=lat' > events/synthetic/wakeup_latency/trigger +ping localhost -c 5 +if ! grep -q "ping" events/synthetic/wakeup_latency/hist; then + fail "Failed to create onmatch action inter-event histogram" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc new file mode 100644 index 000000000000..7907d8aacde3 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc @@ -0,0 +1,50 @@ +#!/bin/sh +# description: event trigger - test inter-event histogram trigger onmatch-onmax action + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +clear_synthetic_events +reset_tracer +do_reset + +echo "Test create synthetic event" + +echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +if [ ! -d events/synthetic/wakeup_latency ]; then + fail "Failed to create wakeup_latency synthetic event" +fi + +echo "Test create histogram for synthetic event" +echo "Test histogram variables,simple expression support and onmatch-onmax action" + +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger +echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid,next_comm):onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger +echo 'hist:keys=comm,pid,lat:wakeup_lat=lat:sort=lat' > events/synthetic/wakeup_latency/trigger +ping localhost -c 5 +if [ ! grep -q "ping" events/synthetic/wakeup_latency/hist -o ! grep -q "max:" events/sched/sched_switch/hist]; then + fail "Failed to create onmatch-onmax action inter-event histogram" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc new file mode 100644 index 000000000000..38b7ed6242b2 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc @@ -0,0 +1,48 @@ +#!/bin/sh +# description: event trigger - test inter-event histogram trigger onmax action + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +clear_synthetic_events +reset_tracer +do_reset + +echo "Test create synthetic event" + +echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +if [ ! -d events/synthetic/wakeup_latency ]; then + fail "Failed to create wakeup_latency synthetic event" +fi + +echo "Test onmax action" + +echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_waking/trigger +echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger +ping localhost -c 3 +if ! grep -q "max:" events/sched/sched_switch/hist; then + fail "Failed to create onmax action inter-event histogram" +fi + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc new file mode 100644 index 000000000000..cef11377dcbd --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc @@ -0,0 +1,54 @@ +#!/bin/sh +# description: event trigger - test synthetic event create remove +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit_fail +} + +if [ ! -f set_event ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f synthetic_events ]; then + echo "synthetic event is not supported" + exit_unsupported +fi + +clear_synthetic_events +reset_tracer +do_reset + +echo "Test create synthetic event" + +echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +if [ ! -d events/synthetic/wakeup_latency ]; then + fail "Failed to create wakeup_latency synthetic event" +fi + +reset_trigger + +echo "Test create synthetic event with an error" +echo 'wakeup_latency u64 lat pid_t pid char' > synthetic_events > /dev/null +if [ -d events/synthetic/wakeup_latency ]; then + fail "Created wakeup_latency synthetic event with an invalid format" +fi + +reset_trigger + +echo "Test remove synthetic event" +echo '!wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events +if [ -d events/synthetic/wakeup_latency ]; then + fail "Failed to delete wakeup_latency synthetic event" +fi + +do_reset + +exit 0 |