lwn.git/kernel/events, branch v4.14-rc4

perf/aux: Only update ->aux_wakeup in non-overwrite mode

2017-09-29T08:06:45+00:00

The following commit: d9a50b0256 ("perf/aux: Ensure aux_wakeup represents most recent wakeup index") changed the AUX wakeup position calculation to rounddown(), which causes a division-by-zero in AUX overwrite mode (aka "snapshot mode"). The zero denominator results from the fact that perf record doesn't set aux_watermark to anything, in which case the kernel will set it to half the AUX buffer size, but only for non-overwrite mode. In the overwrite mode aux_watermark stays zero. The good news is that, AUX overwrite mode, wakeups don't happen and related bookkeeping is not relevant, so we can simply forego the whole wakeup updates. Signed-off-by: Alexander Shishkin Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/20170906160811.16510-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar

bpf: one perf event close won't free bpf program attached by another perf event

2017-09-20T21:10:29+00:00

This patch fixes a bug exhibited by the following scenario: 1. fd1 = perf_event_open with attr.config = ID1 2. attach bpf program prog1 to fd1 3. fd2 = perf_event_open with attr.config = ID1 4. user program closes fd2 and prog1 is detached from the tracepoint. 5. user program with fd1 does not work properly as tracepoint no output any more. The issue happens at step 4. Multiple perf_event_open can be called successfully, but only one bpf prog pointer in the tp_event. In the current logic, any fd release for the same tp_event will free the tp_event->prog. The fix is to free tp_event->prog only when the closing fd corresponds to the one which registered the program. Signed-off-by: Yonghong Song Signed-off-by: David S. Miller

Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2017-09-07T05:25:25+00:00

Pull cgroup updates from Tejun Heo: "Several notable changes this cycle: - Thread mode was merged. This will be used for cgroup2 support for CPU and possibly other controllers. Unfortunately, CPU controller cgroup2 support didn't make this pull request but most contentions have been resolved and the support is likely to be merged before the next merge window. - cgroup.stat now shows the number of descendant cgroups. - cpuset now can enable the easier-to-configure v2 behavior on v1 hierarchy" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: Allow v2 behavior in v1 cgroup cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup cgroup: remove unneeded checks cgroup: misc changes cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy cgroup: re-use the parent pointer in cgroup_destroy_locked() cgroup: add cgroup.stat interface with basic hierarchy stats cgroup: implement hierarchy limits cgroup: keep track of number of descent cgroups cgroup: add comment to cgroup_enable_threaded() cgroup: remove unnecessary empty check when enabling threaded mode cgroup: update debug controller to print out thread mode information cgroup: implement cgroup v2 thread support cgroup: implement CSS_TASK_ITER_THREADED cgroup: introduce cgroup->dom_cgrp and threaded css_set handling cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS cgroup: reorganize cgroup.procs / task write path cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets cgroup: distinguish local and children populated states cgroup: remove now unused list_head @pending in cgroup_apply_cftypes() ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2017-09-06T21:45:08+00:00

Pull networking updates from David Miller: 1) Support ipv6 checksum offload in sunvnet driver, from Shannon Nelson. 2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric Dumazet. 3) Allow generic XDP to work on virtual devices, from John Fastabend. 4) Add bpf device maps and XDP_REDIRECT, which can be used to build arbitrary switching frameworks using XDP. From John Fastabend. 5) Remove UFO offloads from the tree, gave us little other than bugs. 6) Remove the IPSEC flow cache, from Florian Westphal. 7) Support ipv6 route offload in mlxsw driver. 8) Support VF representors in bnxt_en, from Sathya Perla. 9) Add support for forward error correction modes to ethtool, from Vidya Sagar Ravipati. 10) Add time filter for packet scheduler action dumping, from Jamal Hadi Salim. 11) Extend the zerocopy sendmsg() used by virtio and tap to regular sockets via MSG_ZEROCOPY. From Willem de Bruijn. 12) Significantly rework value tracking in the BPF verifier, from Edward Cree. 13) Add new jump instructions to eBPF, from Daniel Borkmann. 14) Rework rtnetlink plumbing so that operations can be run without taking the RTNL semaphore. From Florian Westphal. 15) Support XDP in tap driver, from Jason Wang. 16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal. 17) Add Huawei hinic ethernet driver. 18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan Delalande. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits) i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq i40e: avoid NVM acquire deadlock during NVM update drivers: net: xgene: Remove return statement from void function drivers: net: xgene: Configure tx/rx delay for ACPI drivers: net: xgene: Read tx/rx delay for ACPI rocker: fix kcalloc parameter order rds: Fix non-atomic operation on shared flag variable net: sched: don't use GFP_KERNEL under spin lock vhost_net: correctly check tx avail during rx busy polling net: mdio-mux: add mdio_mux parameter to mdio_mux_init() rxrpc: Make service connection lookup always check for retry net: stmmac: Delete dead code for MDIO registration gianfar: Fix Tx flow control deactivation cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6 cxgb4: Fix pause frame count in t4_get_port_stats cxgb4: fix memory leak tun: rename generic_xdp to skb_xdp tun: reserve extra headroom only when XDP is set net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping net: dsa: bcm_sf2: Advertise number of egress queues ...

Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04T20:56:37+00:00

Pull x86 cache quality monitoring update from Thomas Gleixner: "This update provides a complete rewrite of the Cache Quality Monitoring (CQM) facility. The existing CQM support was duct taped into perf with a lot of issues and the attempts to fix those turned out to be incomplete and horrible. After lengthy discussions it was decided to integrate the CQM support into the Resource Director Technology (RDT) facility, which is the obvious choise as in hardware CQM is part of RDT. This allowed to add Memory Bandwidth Monitoring support on top. As a result the mechanisms for allocating cache/memory bandwidth and the corresponding monitoring mechanisms are integrated into a single management facility with a consistent user interface" * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) x86/intel_rdt: Turn off most RDT features on Skylake x86/intel_rdt: Add command line options for resource director technology x86/intel_rdt: Move special case code for Haswell to a quirk function x86/intel_rdt: Remove redundant ternary operator on return x86/intel_rdt/cqm: Improve limbo list processing x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug x86/intel_rdt: Modify the intel_pqr_state for better performance x86/intel_rdt/cqm: Clear the default RMID during hotcpu x86/intel_rdt: Show bitmask of shareable resource with other executing units x86/intel_rdt/mbm: Handle counter overflow x86/intel_rdt/mbm: Add mbm counter initialization x86/intel_rdt/mbm: Basic counting of MBM events (total and local) x86/intel_rdt/cqm: Add CPU hotplug support x86/intel_rdt/cqm: Add sched_in support x86/intel_rdt: Introduce rdt_enable_key for scheduling x86/intel_rdt/cqm: Add mount,umount support x86/intel_rdt/cqm: Add rmdir support x86/intel_rdt: Separate the ctrl bits from rmdir x86/intel_rdt/cqm: Add mon_data x86/intel_rdt: Prepare for RDT monitor data support ...

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04T15:39:02+00:00

Pull perf updates from Ingo Molnar: "Kernel side changes: - Add branch type profiling/tracing support. (Jin Yao) - Add the PERF_SAMPLE_PHYS_ADDR ABI to allow the tracing/profiling of physical memory addresses, where the PMU supports it. (Kan Liang) - Export some PMU capability details in the new /sys/bus/event_source/devices/cpu/caps/ sysfs directory. (Andi Kleen) - Aux data fixes and updates (Will Deacon) - kprobes fixes and updates (Masami Hiramatsu) - AMD uncore PMU driver fixes and updates (Janakarajan Natarajan) On the tooling side, here's a (limited!) list of highlights - there were many other changes that I could not list, see the shortlog and git history for details: UI improvements: - Implement a visual marker for fused x86 instructions in the annotate TUI browser, available now in 'perf report', more work needed to have it available as well in 'perf top' (Jin Yao) Further explanation from one of Jin's patches: │ ┌──cmpl $0x0,argp_program_version_hook 81.93 │ ├──je 20 │ │ lock cmpxchg %esi,0x38a9a4(%rip) │ │↓ jne 29 │ │↓ jmp 43 11.47 │20:└─→cmpxch %esi,0x38a999(%rip) That means the cmpl+je is a fused instruction pair and they should be considered together. - Record the branch type and then show statistics and info about in callchain entries (Jin Yao) Example from one of Jin's patches: # perf record -g -j any,save_type # perf report --branch-history --stdio --no-children 38.50% div.c:45 [.] main div | ---main div.c:42 (RET CROSS_2M cycles:2) compute_flag div.c:28 (cycles:2) compute_flag div.c:27 (RET CROSS_2M cycles:1) rand rand.c:28 (cycles:1) rand rand.c:28 (RET CROSS_2M cycles:1) __random random.c:298 (cycles:1) __random random.c:297 (COND_BWD CROSS_2M cycles:1) __random random.c:295 (cycles:1) __random random.c:295 (COND_BWD CROSS_2M cycles:1) __random random.c:295 (cycles:1) __random random.c:295 (RET CROSS_2M cycles:9) namespaces support: - Add initial support for namespaces, using setns to access files in namespaces, grabbing their build-ids, etc. (Krister Johansen) perf trace enhancements: - Beautify pkey_{alloc,free,mprotect} arguments in 'perf trace' (Arnaldo Carvalho de Melo) - Add initial 'clone' syscall args beautifier in 'perf trace' (Arnaldo Carvalho de Melo) - Ignore 'fd' and 'offset' args for MAP_ANONYMOUS in 'perf trace' (Arnaldo Carvalho de Melo) - Beautifiers for the 'cmd' arg of several ioctl types, including: sound, DRM, KVM, vhost virtio and perf_events. (Arnaldo Carvalho de Melo) - Add PERF_SAMPLE_CALLCHAIN and PERF_RECORD_MMAP[2] to 'perf data' CTF conversion, allowing CTF trace visualization tools to show callchains and to resolve symbols (Geneviève Bastien) - Beautify the fcntl syscall, which is an interesting one in the sense that infrastructure had to be put in place to change the formatters of some arguments according to the value in a previous one, i.e. cmd dictates how arg and the syscall return will be formatted. (Arnaldo Carvalho de Melo perf stat enhancements: - Use group read for event groups in 'perf stat', reducing overhead when groups are defined in the event specification, i.e. when using {} to enclose a list of events, asking them to be read at the same time, e.g.: "perf stat -e '{cycles,instructions}'" (Jiri Olsa) pipe mode improvements: - Process tracing data in 'perf annotate' pipe mode (David Carrillo-Cisneros) - Add header record types to pipe-mode, now this command: $ perf record -o - -e cycles sleep 1 | perf report --stdio --header Will show the same as in non-pipe mode, i.e. involving a perf.data file (David Carrillo-Cisneros) Vendor specific hardware event support updates/enhancements: - Update POWER9 vendor events tables (Sukadev Bhattiprolu) - Add POWER9 PMU events Sukadev (Bhattiprolu) - Support additional POWER8+ PVR in PMU mapfile (Shriya) - Add Skylake server uncore JSON vendor events (Andi Kleen) - Support exporting Intel PT data to sqlite3 with python perf scripts, this is in addition to the postgresql support that was already there (Adrian Hunter)" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (253 commits) perf symbols: Fix plt entry calculation for ARM and AARCH64 perf probe: Fix kprobe blacklist checking condition perf/x86: Fix caps/ for !Intel perf/core, x86: Add PERF_SAMPLE_PHYS_ADDR perf/core, pt, bts: Get rid of itrace_started perf trace beauty: Beautify pkey_{alloc,free,mprotect} arguments tools headers: Sync cpu features kernel ABI headers with tooling headers perf tools: Pass full path of FEATURES_DUMP perf tools: Robustify detection of clang binary tools lib: Allow external definition of CC, AR and LD perf tools: Allow external definition of flex and bison binary names tools build tests: Don't hardcode gcc name perf report: Group stat values on global event id perf values: Zero value buffers perf values: Fix allocation check perf values: Fix thread index bug perf report: Add dump_read function perf record: Set read_format for inherit_stat perf c2c: Fix remote HITM detection for Skylake perf tools: Fix static build with newer toolchains ...

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-03T16:23:23+00:00

Pull perf fixes from Thomas Gleixner: - Prevent a potential inconistency in the perf user space access which might lead to evading sanity checks. - Prevent perf recording function trace entries twice * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/ftrace: Fix double traces of perf on ftrace:function perf/core: Fix potential double-fetch bug

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-09-02T00:42:05+00:00

Three cases of simple overlapping changes. Signed-off-by: David S. Miller

mm, uprobes: fix multiple free of ->uprobes_state.xol_area

2017-08-31T23:33:15+00:00

Commit 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for write killable") made it possible to kill a forking task while it is waiting to acquire its ->mmap_sem for write, in dup_mmap(). However, it was overlooked that this introduced an new error path before the new mm_struct's ->uprobes_state.xol_area has been set to NULL after being copied from the old mm_struct by the memcpy in dup_mm(). For a task that has previously hit a uprobe tracepoint, this resulted in the 'struct xol_area' being freed multiple times if the task was killed at just the right time while forking. Fix it by setting ->uprobes_state.xol_area to NULL in mm_init() rather than in uprobe_dup_mmap(). With CONFIG_UPROBE_EVENTS=y, the bug can be reproduced by the same C program given by commit 2b7e8665b4ff ("fork: fix incorrect fput of ->exe_file causing use-after-free"), provided that a uprobe tracepoint has been set on the fork_thread() function. For example: $ gcc reproducer.c -o reproducer -lpthread $ nm reproducer | grep fork_thread 0000000000400719 t fork_thread $ echo "p $PWD/reproducer:0x719" > /sys/kernel/debug/tracing/uprobe_events $ echo 1 > /sys/kernel/debug/tracing/events/uprobes/enable $ ./reproducer Here is the use-after-free reported by KASAN: BUG: KASAN: use-after-free in uprobe_clear_state+0x1c4/0x200 Read of size 8 at addr ffff8800320a8b88 by task reproducer/198 CPU: 1 PID: 198 Comm: reproducer Not tainted 4.13.0-rc7-00015-g36fde05f3fb5 #255 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 Call Trace: dump_stack+0xdb/0x185 print_address_description+0x7e/0x290 kasan_report+0x23b/0x350 __asan_report_load8_noabort+0x19/0x20 uprobe_clear_state+0x1c4/0x200 mmput+0xd6/0x360 do_exit+0x740/0x1670 do_group_exit+0x13f/0x380 get_signal+0x597/0x17d0 do_signal+0x99/0x1df0 exit_to_usermode_loop+0x166/0x1e0 syscall_return_slowpath+0x258/0x2c0 entry_SYSCALL_64_fastpath+0xbc/0xbe ... Allocated by task 199: save_stack_trace+0x1b/0x20 kasan_kmalloc+0xfc/0x180 kmem_cache_alloc_trace+0xf3/0x330 __create_xol_area+0x10f/0x780 uprobe_notify_resume+0x1674/0x2210 exit_to_usermode_loop+0x150/0x1e0 prepare_exit_to_usermode+0x14b/0x180 retint_user+0x8/0x20 Freed by task 199: save_stack_trace+0x1b/0x20 kasan_slab_free+0xa8/0x1a0 kfree+0xba/0x210 uprobe_clear_state+0x151/0x200 mmput+0xd6/0x360 copy_process.part.8+0x605f/0x65d0 _do_fork+0x1a5/0xbd0 SyS_clone+0x19/0x20 do_syscall_64+0x22f/0x660 return_from_SYSCALL_64+0x0/0x7a Note: without KASAN, you may instead see a "Bad page state" message, or simply a general protection fault. Link: http://lkml.kernel.org/r/20170830033303.17927-1-ebiggers3@gmail.com Fixes: 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for write killable") Signed-off-by: Eric Biggers Reported-by: Oleg Nesterov Acked-by: Oleg Nesterov Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Konstantin Khlebnikov Cc: Mark Rutland Cc: Michal Hocko Cc: Peter Zijlstra Cc: Vlastimil Babka Cc: [4.7+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

perf/core, x86: Add PERF_SAMPLE_PHYS_ADDR

2017-08-29T13:09:25+00:00

For understanding how the workload maps to memory channels and hardware behavior, it's very important to collect address maps with physical addresses. For example, 3D XPoint access can only be found by filtering the physical address. Add a new sample type for physical address. perf already has a facility to collect data virtual address. This patch introduces a function to convert the virtual address to physical address. The function is quite generic and can be extended to any architecture as long as a virtual address is provided. - For kernel direct mapping addresses, virt_to_phys is used to convert the virtual addresses to physical address. - For user virtual addresses, __get_user_pages_fast is used to walk the pages tables for user physical address. - This does not work for vmalloc addresses right now. These are not resolved, but code to do that could be added. The new sample type requires collecting the virtual address. The virtual address will not be output unless SAMPLE_ADDR is applied. For security, the physical address can only be exposed to root or privileged user. Tested-by: Madhavan Srinivasan Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: acme@kernel.org Cc: mpe@ellerman.id.au Link: http://lkml.kernel.org/r/1503967969-48278-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar