From 60f1d5e3bac44b598f67d36062da96c095d2b700 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 5 Oct 2016 20:58:15 +0900 Subject: ftrace: Support full glob matching Use glob_match() to support flexible glob wildcards (*,?) and character classes ([) for ftrace. Since the full glob matching is slower than the current partial matching routines(*pat, pat*, *pat*), this leaves those routines and just add MATCH_GLOB for complex glob expression. e.g. ---- [root@localhost tracing]# echo 'sched*group' > set_ftrace_filter [root@localhost tracing]# cat set_ftrace_filter sched_free_group sched_change_group sched_create_group sched_online_group sched_destroy_group sched_offline_group [root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter [root@localhost tracing]# head set_ftrace_filter sys_arch_prctl sys_rt_sigreturn sys_ioperm SyS_iopl sys_modify_ldt SyS_mmap SyS_set_thread_area SyS_get_thread_area SyS_set_tid_address sys_fork ---- Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox Acked-by: Namhyung Kim Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 2 ++ kernel/trace/ftrace.c | 4 ++++ kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 2 ++ kernel/trace/trace_events_filter.c | 17 ++++++++++++++++- 5 files changed, 25 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 2a96b063d659..d5038005eb5d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -70,6 +70,7 @@ config FTRACE_NMI_ENTER config EVENT_TRACING select CONTEXT_SWITCH_TRACER + select GLOB bool config CONTEXT_SWITCH_TRACER @@ -133,6 +134,7 @@ config FUNCTION_TRACER select KALLSYMS select GENERIC_TRACER select CONTEXT_SWITCH_TRACER + select GLOB help Enable the kernel to trace every kernel function. This is done by using a compiler feature to insert a small, 5-byte No-Operation diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index da87b3cba5b3..356bb70d071e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3511,6 +3511,10 @@ static int ftrace_match(char *str, struct ftrace_glob *g) memcmp(str + slen - g->len, g->search, g->len) == 0) matched = 1; break; + case MATCH_GLOB: + if (glob_match(g->search, str)) + matched = 1; + break; } return matched; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8696ce6bf2f6..d904516dfdab 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4065,7 +4065,7 @@ static const char readme_msg[] = "\n available_filter_functions - list of functions that can be filtered on\n" " set_ftrace_filter\t- echo function name in here to only trace these\n" "\t\t\t functions\n" - "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" + "\t accepts: func_full_name or glob-matching-pattern\n" "\t modules: Can select a group via module\n" "\t Format: :mod:\n" "\t example: echo :mod:ext3 > set_ftrace_filter\n" diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fd24b1f9ac43..4b7918902ab8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -15,6 +15,7 @@ #include #include #include +#include #ifdef CONFIG_FTRACE_SYSCALLS #include /* For NR_SYSCALLS */ @@ -1257,6 +1258,7 @@ enum regex_type { MATCH_FRONT_ONLY, MATCH_MIDDLE_ONLY, MATCH_END_ONLY, + MATCH_GLOB, }; struct regex { diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 9daa9b3bc6d9..e1c7e2cdc240 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -344,6 +344,12 @@ static int regex_match_end(char *str, struct regex *r, int len) return 0; } +static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused) +{ + if (glob_match(r->pattern, str)) + return 1; + return 0; +} /** * filter_parse_regex - parse a basic regex * @buff: the raw regex @@ -380,14 +386,20 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) if (!i) { *search = buff + 1; type = MATCH_END_ONLY; - } else { + } else if (i == len - 1) { if (type == MATCH_END_ONLY) type = MATCH_MIDDLE_ONLY; else type = MATCH_FRONT_ONLY; buff[i] = 0; break; + } else { /* pattern continues, use full glob */ + type = MATCH_GLOB; + break; } + } else if (strchr("[?\\", buff[i])) { + type = MATCH_GLOB; + break; } } @@ -420,6 +432,9 @@ static void filter_build_regex(struct filter_pred *pred) case MATCH_END_ONLY: r->match = regex_match_end; break; + case MATCH_GLOB: + r->match = regex_match_glob; + break; } pred->not ^= not; -- cgit v1.2.3 From fdf5b679864b8a1165712164b8f17debeb6b10b6 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 25 Oct 2016 16:14:28 -0400 Subject: tracing: Optimise comparison filters and fix binary and for 64 bit Currently the filter logic for comparisons (like greater-than and less-than) are used, they share the same function and a switch statement is used to jump to the comparison type to perform. This is done in the extreme hot path of the tracing code, and it does not take much more space to create a unique comparison function to perform each type of comparison and remove the switch statement. Also, a bug was found where the binary and operation for 64 bits could fail if the resulting bits were greater than 32 bits, because the result was passed into a 32 bit variable. This was fixed when adding the separate binary and function. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 80 +++++++++++++++++++++++--------------- 1 file changed, 48 insertions(+), 32 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e1c7e2cdc240..1ba7a6b86f55 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -145,34 +145,50 @@ struct pred_stack { /* If not of not match is equal to not of not, then it is a match */ #define DEFINE_COMPARISON_PRED(type) \ -static int filter_pred_##type(struct filter_pred *pred, void *event) \ +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 = 0; \ - \ - switch (pred->op) { \ - case OP_LT: \ - match = (*addr < val); \ - break; \ - case OP_LE: \ - match = (*addr <= val); \ - break; \ - case OP_GT: \ - match = (*addr > val); \ - break; \ - case OP_GE: \ - match = (*addr >= val); \ - break; \ - case OP_BAND: \ - match = (*addr & val); \ - break; \ - default: \ - break; \ - } \ - \ + int match = (*addr < val); \ return !!match == !pred->not; \ -} +} \ +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; \ +} \ +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; \ +} \ +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; \ +} \ +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; \ +} \ +static const filter_pred_fn_t pred_funcs_##type[] = { \ + filter_pred_LT_##type, \ + filter_pred_LE_##type, \ + filter_pred_GT_##type, \ + filter_pred_GE_##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) \ @@ -982,33 +998,33 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size, if (op == OP_EQ || op == OP_NE) fn = filter_pred_64; else if (field_is_signed) - fn = filter_pred_s64; + fn = pred_funcs_s64[op - PRED_FUNC_START]; else - fn = filter_pred_u64; + fn = pred_funcs_u64[op - PRED_FUNC_START]; break; case 4: if (op == OP_EQ || op == OP_NE) fn = filter_pred_32; else if (field_is_signed) - fn = filter_pred_s32; + fn = pred_funcs_s32[op - PRED_FUNC_START]; else - fn = filter_pred_u32; + fn = pred_funcs_u32[op - PRED_FUNC_START]; break; case 2: if (op == OP_EQ || op == OP_NE) fn = filter_pred_16; else if (field_is_signed) - fn = filter_pred_s16; + fn = pred_funcs_s16[op - PRED_FUNC_START]; else - fn = filter_pred_u16; + fn = pred_funcs_u16[op - PRED_FUNC_START]; break; case 1: if (op == OP_EQ || op == OP_NE) fn = filter_pred_8; else if (field_is_signed) - fn = filter_pred_s8; + fn = pred_funcs_s8[op - PRED_FUNC_START]; else - fn = filter_pred_u8; + fn = pred_funcs_u8[op - PRED_FUNC_START]; break; } -- cgit v1.2.3 From 3f303fbccfc423a28765df6e1be0428fdf1aac59 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 26 Oct 2016 15:58:03 -0400 Subject: tracing/filter: Define op as the enum that it is The trace_events_file.c filter logic can be a bit complex. I copy this into a userspace program where I can debug it a bit easier. One issue is the op is defined in most places as an int instead of as an enum, and gdb just gives the value when debugging. Having the actual op name shown in gdb is more useful. This has no functionality change, but helps in debugging when the file is debugged in user space. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 1ba7a6b86f55..59a411ff60c7 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -108,12 +108,12 @@ static char *err_text[] = { }; struct opstack_op { - int op; + enum filter_op_ids op; struct list_head list; }; struct postfix_elt { - int op; + enum filter_op_ids op; char *operand; struct list_head list; }; @@ -977,7 +977,7 @@ int filter_assign_type(const char *type) return FILTER_OTHER; } -static bool is_legal_op(struct ftrace_event_field *field, int op) +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)) @@ -988,8 +988,8 @@ static bool is_legal_op(struct ftrace_event_field *field, int op) return true; } -static filter_pred_fn_t select_comparison_fn(int op, int field_size, - int field_is_signed) +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; @@ -1197,7 +1197,8 @@ static inline int append_operand_char(struct filter_parse_state *ps, char c) return 0; } -static int filter_opstack_push(struct filter_parse_state *ps, int op) +static int filter_opstack_push(struct filter_parse_state *ps, + enum filter_op_ids op) { struct opstack_op *opstack_op; @@ -1231,7 +1232,7 @@ static int filter_opstack_top(struct filter_parse_state *ps) static int filter_opstack_pop(struct filter_parse_state *ps) { struct opstack_op *opstack_op; - int op; + enum filter_op_ids op; if (filter_opstack_empty(ps)) return OP_NONE; @@ -1276,7 +1277,7 @@ static int postfix_append_operand(struct filter_parse_state *ps, char *operand) return 0; } -static int postfix_append_op(struct filter_parse_state *ps, int op) +static int postfix_append_op(struct filter_parse_state *ps, enum filter_op_ids op) { struct postfix_elt *elt; @@ -1306,8 +1307,8 @@ static void postfix_clear(struct filter_parse_state *ps) static int filter_parse(struct filter_parse_state *ps) { + enum filter_op_ids op, top_op; int in_string = 0; - int op, top_op; char ch; while ((ch = infix_next(ps))) { @@ -1398,7 +1399,8 @@ parse_operand: static struct filter_pred *create_pred(struct filter_parse_state *ps, struct trace_event_call *call, - int op, char *operand1, char *operand2) + enum filter_op_ids op, + char *operand1, char *operand2) { struct ftrace_event_field *field; static struct filter_pred pred; -- cgit v1.2.3 From 8d414bd2f77ce858f6b9d119c63b9ce29cf0b75d Mon Sep 17 00:00:00 2001 From: Zhou Chengming Date: Mon, 14 Nov 2016 11:19:13 +0800 Subject: tracing: Allow wakeup_dl tracer to be used by instances Allow wakeup_dl tracer to be used by instances, like wakeup tracer and wakeup_rt tracer. Link: http://lkml.kernel.org/r/1479093553-31264-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Zhou Chengming Signed-off-by: Steven Rostedt --- kernel/trace/trace_sched_wakeup.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 9d4399b553a3..1bf2324dc682 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -790,6 +790,7 @@ static struct tracer wakeup_dl_tracer __read_mostly = #endif .open = wakeup_trace_open, .close = wakeup_trace_close, + .allow_instances = true, .use_max_tr = true, }; -- cgit v1.2.3 From fa32e8557b470f5ff90babc6cbacc61535a81a0f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 6 Jul 2016 15:25:08 -0400 Subject: tracing: Add new trace_marker_raw A new file is created: /sys/kernel/debug/tracing/trace_marker_raw This allows for appications to create data structures and write the binary data directly into it, and then read the trace data out from trace_pipe_raw into the same type of data structure. This saves on converting numbers into ASCII that would be required by trace_marker. Suggested-by: Olof Johansson Signed-off-by: Steven Rostedt --- Documentation/trace/ftrace.txt | 6 ++ kernel/trace/trace.c | 165 +++++++++++++++++++++++++++++++++-------- kernel/trace/trace.h | 2 + kernel/trace/trace_entries.h | 15 ++++ kernel/trace/trace_output.c | 30 ++++++++ 5 files changed, 187 insertions(+), 31 deletions(-) (limited to 'kernel') diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 1bc66c1db0cb..6c374c5fe400 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -396,6 +396,12 @@ of ftrace. Here is a list of some of the key files: trace_fd = open("trace_marker", WR_ONLY); + trace_marker_raw: + + This is similar to trace_marker above, but is meant for for binary data + to be written to it, where a tool can be used to parse the data + from trace_pipe_raw. + uprobe_events: Add dynamic tracepoints in programs. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d904516dfdab..57069e7f369c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4054,6 +4054,7 @@ static const char readme_msg[] = " x86-tsc: TSC cycle counter\n" #endif "\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" " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" "\t\t\t Remove sub-buffer with rmdir\n" @@ -5514,35 +5515,15 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp) return 0; } -static ssize_t -tracing_mark_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *fpos) +static inline int lock_user_pages(const char __user *ubuf, size_t cnt, + struct page **pages, void **map_page, + int *offset) { unsigned long addr = (unsigned long)ubuf; - struct trace_array *tr = filp->private_data; - struct ring_buffer_event *event; - struct ring_buffer *buffer; - struct print_entry *entry; - unsigned long irq_flags; - struct page *pages[2]; - void *map_page[2]; int nr_pages = 1; - ssize_t written; - int offset; - int size; - int len; int ret; int i; - if (tracing_disabled) - return -EINVAL; - - if (!(tr->trace_flags & TRACE_ITER_MARKERS)) - return -EINVAL; - - if (cnt > TRACE_BUF_SIZE) - cnt = TRACE_BUF_SIZE; - /* * Userspace is injecting traces into the kernel trace buffer. * We want to be as non intrusive as possible. @@ -5557,26 +5538,70 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, * pages directly. We then write the data directly into the * ring buffer. */ - BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); /* check if we cross pages */ if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) nr_pages = 2; - offset = addr & (PAGE_SIZE - 1); + *offset = addr & (PAGE_SIZE - 1); addr &= PAGE_MASK; ret = get_user_pages_fast(addr, nr_pages, 0, pages); if (ret < nr_pages) { while (--ret >= 0) put_page(pages[ret]); - written = -EFAULT; - goto out; + return -EFAULT; } for (i = 0; i < nr_pages; i++) map_page[i] = kmap_atomic(pages[i]); + return nr_pages; +} + +static inline void unlock_user_pages(struct page **pages, + void **map_page, int nr_pages) +{ + int i; + + for (i = nr_pages - 1; i >= 0; i--) { + kunmap_atomic(map_page[i]); + put_page(pages[i]); + } +} + +static ssize_t +tracing_mark_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *fpos) +{ + struct trace_array *tr = filp->private_data; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + struct print_entry *entry; + unsigned long irq_flags; + struct page *pages[2]; + void *map_page[2]; + int nr_pages = 1; + ssize_t written; + int offset; + int size; + int len; + + if (tracing_disabled) + return -EINVAL; + + if (!(tr->trace_flags & TRACE_ITER_MARKERS)) + return -EINVAL; + + if (cnt > TRACE_BUF_SIZE) + cnt = TRACE_BUF_SIZE; + + BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); + + nr_pages = lock_user_pages(ubuf, cnt, pages, map_page, &offset); + if (nr_pages < 0) + return nr_pages; + local_save_flags(irq_flags); size = sizeof(*entry) + cnt + 2; /* possible \n added */ buffer = tr->trace_buffer.buffer; @@ -5611,11 +5636,79 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, *fpos += written; out_unlock: - for (i = nr_pages - 1; i >= 0; i--) { - kunmap_atomic(map_page[i]); - put_page(pages[i]); + unlock_user_pages(pages, map_page, nr_pages); + + return written; +} + +/* Limit it for now to 3K (including tag) */ +#define RAW_DATA_MAX_SIZE (1024*3) + +static ssize_t +tracing_mark_raw_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *fpos) +{ + struct trace_array *tr = filp->private_data; + struct ring_buffer_event *event; + struct ring_buffer *buffer; + struct raw_data_entry *entry; + unsigned long irq_flags; + struct page *pages[2]; + void *map_page[2]; + int nr_pages = 1; + ssize_t written; + int offset; + int size; + int len; + + if (tracing_disabled) + return -EINVAL; + + if (!(tr->trace_flags & TRACE_ITER_MARKERS)) + return -EINVAL; + + /* The marker must at least have a tag id */ + if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE) + return -EINVAL; + + if (cnt > TRACE_BUF_SIZE) + cnt = TRACE_BUF_SIZE; + + BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); + + nr_pages = lock_user_pages(ubuf, cnt, pages, map_page, &offset); + if (nr_pages < 0) + return nr_pages; + + local_save_flags(irq_flags); + size = sizeof(*entry) + cnt; + buffer = tr->trace_buffer.buffer; + event = trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, + irq_flags, preempt_count()); + if (!event) { + /* Ring buffer disabled, return as if not open for write */ + written = -EBADF; + goto out_unlock; } - out: + + entry = ring_buffer_event_data(event); + + if (nr_pages == 2) { + len = PAGE_SIZE - offset; + memcpy(&entry->id, map_page[0] + offset, len); + memcpy(((char *)&entry->id) + len, map_page[1], cnt - len); + } else + memcpy(&entry->id, map_page[0] + offset, cnt); + + __buffer_unlock_commit(buffer, event); + + written = cnt; + + *fpos += written; + + out_unlock: + unlock_user_pages(pages, map_page, nr_pages); + return written; } @@ -5945,6 +6038,13 @@ static const struct file_operations tracing_mark_fops = { .release = tracing_release_generic_tr, }; +static const struct file_operations tracing_mark_raw_fops = { + .open = tracing_open_generic_tr, + .write = tracing_mark_raw_write, + .llseek = generic_file_llseek, + .release = tracing_release_generic_tr, +}; + static const struct file_operations trace_clock_fops = { .open = tracing_clock_open, .read = seq_read, @@ -7214,6 +7314,9 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_marker", 0220, d_tracer, tr, &tracing_mark_fops); + trace_create_file("trace_marker_raw", 0220, d_tracer, + tr, &tracing_mark_raw_fops); + trace_create_file("trace_clock", 0644, d_tracer, tr, &trace_clock_fops); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 4b7918902ab8..9294f8606ade 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -40,6 +40,7 @@ enum trace_type { TRACE_BLK, TRACE_BPUTS, TRACE_HWLAT, + TRACE_RAW_DATA, __TRACE_LAST_TYPE, }; @@ -331,6 +332,7 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \ IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \ IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \ + IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ TRACE_MMIO_RW); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index d1cc37e78f99..eb7396b7e7c3 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -244,6 +244,21 @@ FTRACE_ENTRY(print, print_entry, FILTER_OTHER ); +FTRACE_ENTRY(raw_data, raw_data_entry, + + TRACE_RAW_DATA, + + F_STRUCT( + __field( unsigned int, id ) + __dynamic_array( char, buf ) + ), + + F_printk("id:%04x %08x", + __entry->id, (int)__entry->buf[0]), + + FILTER_OTHER +); + FTRACE_ENTRY(bputs, bputs_entry, TRACE_BPUTS, diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 3fc20422c166..5d33a7352919 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1288,6 +1288,35 @@ static struct trace_event trace_print_event = { .funcs = &trace_print_funcs, }; +static enum print_line_t trace_raw_data(struct trace_iterator *iter, int flags, + struct trace_event *event) +{ + struct raw_data_entry *field; + int i; + + trace_assign_type(field, iter->ent); + + trace_seq_printf(&iter->seq, "# %x buf:", field->id); + + for (i = 0; i < iter->ent_size - offsetof(struct raw_data_entry, buf); i++) + trace_seq_printf(&iter->seq, " %02x", + (unsigned char)field->buf[i]); + + trace_seq_putc(&iter->seq, '\n'); + + return trace_handle_return(&iter->seq); +} + +static struct trace_event_functions trace_raw_data_funcs = { + .trace = trace_raw_data, + .raw = trace_raw_data, +}; + +static struct trace_event trace_raw_data_event = { + .type = TRACE_RAW_DATA, + .funcs = &trace_raw_data_funcs, +}; + static struct trace_event *events[] __initdata = { &trace_fn_event, @@ -1299,6 +1328,7 @@ static struct trace_event *events[] __initdata = { &trace_bprint_event, &trace_print_event, &trace_hwlat_event, + &trace_raw_data_event, NULL }; -- cgit v1.2.3 From 478409dd683db76cbcfe7bf8332a37f01deb0a2d Mon Sep 17 00:00:00 2001 From: Chunyan Zhang Date: Mon, 21 Nov 2016 15:57:18 +0800 Subject: tracing: Add hook to function tracing for other subsystems to use Currently Function traces can be only exported to the ring buffer. This adds a trace_export concept which can process traces and export them to a registered destination as an addition to the current one that outputs to Ftrace - i.e. ring buffer. In this way, if we want function traces to be sent to other destinations rather than only to the ring buffer, we just need to register a new trace_export and implement its own .write() function for writing traces to storage. With this patch, only function tracing (trace type is TRACE_FN) is supported. Link: http://lkml.kernel.org/r/1479715043-6534-2-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang Signed-off-by: Steven Rostedt --- include/linux/trace.h | 28 +++++++++++ kernel/trace/trace.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 156 insertions(+), 1 deletion(-) create mode 100644 include/linux/trace.h (limited to 'kernel') diff --git a/include/linux/trace.h b/include/linux/trace.h new file mode 100644 index 000000000000..9330a58e2651 --- /dev/null +++ b/include/linux/trace.h @@ -0,0 +1,28 @@ +#ifndef _LINUX_TRACE_H +#define _LINUX_TRACE_H + +#ifdef CONFIG_TRACING +/* + * The trace export - an export of Ftrace output. The trace_export + * can process traces and export them to a registered destination as + * an addition to the current only output of Ftrace - i.e. ring buffer. + * + * If you want traces to be sent to some other place rather than ring + * buffer only, just need to register a new trace_export and implement + * its own .write() function for writing traces to the storage. + * + * next - pointer to the next trace_export + * write - copy traces which have been delt with ->commit() to + * the destination + */ +struct trace_export { + struct trace_export __rcu *next; + void (*write)(const void *, unsigned int); +}; + +int register_ftrace_export(struct trace_export *export); +int unregister_ftrace_export(struct trace_export *export); + +#endif /* CONFIG_TRACING */ + +#endif /* _LINUX_TRACE_H */ diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 57069e7f369c..edccdff8a36d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include "trace.h" @@ -2128,6 +2129,129 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, ftrace_trace_userstack(buffer, flags, pc); } +static void +trace_process_export(struct trace_export *export, + struct ring_buffer_event *event) +{ + struct trace_entry *entry; + unsigned int size = 0; + + entry = ring_buffer_event_data(event); + size = ring_buffer_event_length(event); + export->write(entry, size); +} + +static DEFINE_MUTEX(ftrace_export_lock); + +static struct trace_export __rcu *ftrace_exports_list __read_mostly; + +static DEFINE_STATIC_KEY_FALSE(ftrace_exports_enabled); + +static inline void ftrace_exports_enable(void) +{ + static_branch_enable(&ftrace_exports_enabled); +} + +static inline void ftrace_exports_disable(void) +{ + static_branch_disable(&ftrace_exports_enabled); +} + +void ftrace_exports(struct ring_buffer_event *event) +{ + struct trace_export *export; + + preempt_disable_notrace(); + + export = rcu_dereference_raw_notrace(ftrace_exports_list); + while (export) { + trace_process_export(export, event); + export = rcu_dereference_raw_notrace(export->next); + } + + preempt_enable_notrace(); +} + +static inline void +add_trace_export(struct trace_export **list, struct trace_export *export) +{ + rcu_assign_pointer(export->next, *list); + /* + * We are entering export into the list but another + * CPU might be walking that list. We need to make sure + * the export->next pointer is valid before another CPU sees + * the export pointer included into the list. + */ + rcu_assign_pointer(*list, export); +} + +static inline int +rm_trace_export(struct trace_export **list, struct trace_export *export) +{ + struct trace_export **p; + + for (p = list; *p != NULL; p = &(*p)->next) + if (*p == export) + break; + + if (*p != export) + return -1; + + rcu_assign_pointer(*p, (*p)->next); + + return 0; +} + +static inline void +add_ftrace_export(struct trace_export **list, struct trace_export *export) +{ + if (*list == NULL) + ftrace_exports_enable(); + + add_trace_export(list, export); +} + +static inline int +rm_ftrace_export(struct trace_export **list, struct trace_export *export) +{ + int ret; + + ret = rm_trace_export(list, export); + if (*list == NULL) + ftrace_exports_disable(); + + return ret; +} + +int register_ftrace_export(struct trace_export *export) +{ + if (WARN_ON_ONCE(!export->write)) + return -1; + + mutex_lock(&ftrace_export_lock); + + add_ftrace_export(&ftrace_exports_list, export); + + mutex_unlock(&ftrace_export_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(register_ftrace_export); + +int unregister_ftrace_export(struct trace_export *export) +{ + int ret; + + mutex_lock(&ftrace_export_lock); + + ret = rm_ftrace_export(&ftrace_exports_list, export); + + mutex_unlock(&ftrace_export_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(unregister_ftrace_export); + void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, @@ -2146,8 +2270,11 @@ trace_function(struct trace_array *tr, entry->ip = ip; entry->parent_ip = parent_ip; - if (!call_filter_check_discard(call, entry, buffer, event)) + if (!call_filter_check_discard(call, entry, buffer, event)) { + if (static_branch_unlikely(&ftrace_exports_enabled)) + ftrace_exports(event); __buffer_unlock_commit(buffer, event); + } } #ifdef CONFIG_STACKTRACE -- cgit v1.2.3 From 7d436400223bb46e9f88e6bba6f8d867acf0d82c Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 22 Nov 2016 18:32:03 -0500 Subject: tracing: Add error checks to creation of event files The creation of the set_event_pid file was assigned to a variable "entry" but that variable was never used. Ideally, it should be used to check if the file was created and warn if it was not. The files header_page, header_event should also be checked and a warning if they fail to be created. The "enable" file was moved up, as it is a more crucial file to have and a hard failure (return -ENOMEM) should be returned if it is not created. Reported-by: David Binderman Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 03c0a48c3ac4..ba67ede48822 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2843,20 +2843,32 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) return -ENOMEM; } + entry = trace_create_file("enable", 0644, d_events, + tr, &ftrace_tr_enable_fops); + if (!entry) { + pr_warn("Could not create tracefs 'enable' entry\n"); + return -ENOMEM; + } + + /* There are not as crucial, just warn if they are not created */ + entry = tracefs_create_file("set_event_pid", 0644, parent, tr, &ftrace_set_event_pid_fops); + if (!entry) + pr_warn("Could not create tracefs 'set_event_pid' entry\n"); /* ring buffer internal formats */ - trace_create_file("header_page", 0444, d_events, - ring_buffer_print_page_header, - &ftrace_show_header_fops); - - trace_create_file("header_event", 0444, d_events, - ring_buffer_print_entry_header, - &ftrace_show_header_fops); + entry = trace_create_file("header_page", 0444, d_events, + ring_buffer_print_page_header, + &ftrace_show_header_fops); + if (!entry) + pr_warn("Could not create tracefs 'header_page' entry\n"); - trace_create_file("enable", 0644, d_events, - tr, &ftrace_tr_enable_fops); + entry = trace_create_file("header_event", 0444, d_events, + ring_buffer_print_entry_header, + &ftrace_show_header_fops); + if (!entry) + pr_warn("Could not create tracefs 'header_event' entry\n"); tr->event_dir = d_events; -- cgit v1.2.3 From 3e9a8aadca4807b4eadd33a50014c9b2767a4f1f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 11:29:58 -0500 Subject: tracing: Create a always_inlined __trace_buffer_lock_reserve() As Andi Kleen pointed out in the Link below, the trace events has quite a bit of code execution. A lot of that happens to be calling functions, where some of them should simply be inlined. One of these functions happens to be trace_buffer_lock_reserve() which is also a global, but it is used throughout the file it is defined in. Create a __trace_buffer_lock_reserve() that is always inlined that the file can benefit from. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 87 +++++++++++++++++++++++++++++----------------------- 1 file changed, 48 insertions(+), 39 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index edccdff8a36d..490533726b54 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -739,6 +739,31 @@ static inline void ftrace_trace_stack(struct trace_array *tr, #endif +static __always_inline void +trace_event_setup(struct ring_buffer_event *event, + int type, unsigned long flags, int pc) +{ + struct trace_entry *ent = ring_buffer_event_data(event); + + tracing_generic_entry_update(ent, flags, pc); + ent->type = type; +} + +static __always_inline struct ring_buffer_event * +__trace_buffer_lock_reserve(struct ring_buffer *buffer, + int type, + unsigned long len, + unsigned long flags, int pc) +{ + struct ring_buffer_event *event; + + event = ring_buffer_lock_reserve(buffer, len); + if (event != NULL) + trace_event_setup(event, type, flags, pc); + + return event; +} + static void tracer_tracing_on(struct trace_array *tr) { if (tr->trace_buffer.buffer) @@ -795,8 +820,8 @@ int __trace_puts(unsigned long ip, const char *str, int size) local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; - event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, - irq_flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, + irq_flags, pc); if (!event) return 0; @@ -843,8 +868,8 @@ int __trace_bputs(unsigned long ip, const char *str) local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; - event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, - irq_flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, + irq_flags, pc); if (!event) return 0; @@ -1913,29 +1938,13 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, } EXPORT_SYMBOL_GPL(tracing_generic_entry_update); -static __always_inline void -trace_event_setup(struct ring_buffer_event *event, - int type, unsigned long flags, int pc) -{ - struct trace_entry *ent = ring_buffer_event_data(event); - - tracing_generic_entry_update(ent, flags, pc); - ent->type = type; -} - struct ring_buffer_event * trace_buffer_lock_reserve(struct ring_buffer *buffer, int type, unsigned long len, unsigned long flags, int pc) { - struct ring_buffer_event *event; - - event = ring_buffer_lock_reserve(buffer, len); - if (event != NULL) - trace_event_setup(event, type, flags, pc); - - return event; + return __trace_buffer_lock_reserve(buffer, type, len, flags, pc); } DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event); @@ -2090,8 +2099,8 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, this_cpu_dec(trace_buffered_event_cnt); } - entry = trace_buffer_lock_reserve(*current_rb, - type, len, flags, pc); + entry = __trace_buffer_lock_reserve(*current_rb, + type, len, flags, pc); /* * If tracing is off, but we have triggers enabled * we still need to look at the event data. Use the temp_buffer @@ -2100,8 +2109,8 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, */ if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) { *current_rb = temp_buffer; - entry = trace_buffer_lock_reserve(*current_rb, - type, len, flags, pc); + entry = __trace_buffer_lock_reserve(*current_rb, + type, len, flags, pc); } return entry; } @@ -2262,8 +2271,8 @@ trace_function(struct trace_array *tr, struct ring_buffer_event *event; struct ftrace_entry *entry; - event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), - flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), + flags, pc); if (!event) return; entry = ring_buffer_event_data(event); @@ -2342,8 +2351,8 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, size *= sizeof(unsigned long); - event = trace_buffer_lock_reserve(buffer, TRACE_STACK, - sizeof(*entry) + size, flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_STACK, + sizeof(*entry) + size, flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); @@ -2444,8 +2453,8 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) __this_cpu_inc(user_stack_count); - event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, - sizeof(*entry), flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, + sizeof(*entry), flags, pc); if (!event) goto out_drop_count; entry = ring_buffer_event_data(event); @@ -2615,8 +2624,8 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) local_save_flags(flags); size = sizeof(*entry) + sizeof(u32) * len; buffer = tr->trace_buffer.buffer; - event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, - flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, + flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); @@ -2671,8 +2680,8 @@ __trace_array_vprintk(struct ring_buffer *buffer, local_save_flags(flags); size = sizeof(*entry) + len + 1; - event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, - flags, pc); + event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, + flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); @@ -5732,8 +5741,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, local_save_flags(irq_flags); size = sizeof(*entry) + cnt + 2; /* possible \n added */ buffer = tr->trace_buffer.buffer; - event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, - irq_flags, preempt_count()); + event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, + irq_flags, preempt_count()); if (!event) { /* Ring buffer disabled, return as if not open for write */ written = -EBADF; @@ -5810,8 +5819,8 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf, local_save_flags(irq_flags); size = sizeof(*entry) + cnt; buffer = tr->trace_buffer.buffer; - event = trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, - irq_flags, preempt_count()); + event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, + irq_flags, preempt_count()); if (!event) { /* Ring buffer disabled, return as if not open for write */ written = -EBADF; -- cgit v1.2.3 From fa7ffb39efccd574163ebc5dbfe4ff066186f261 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 11:36:30 -0500 Subject: ring-buffer: Make rb_reserve_next_event() always inlined The function rb_reserved_next_event() is called by two functions: ring_buffer_lock_reserve() and ring_buffer_write(). This is in a very hot path of the tracing code, and it is best that they are not functions. The two callers are basically wrapers for rb_reserver_next_event(). Removing the function calls can save execution time in the hotpath of tracing. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9c143739b8d7..1f3580cee6cc 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2733,7 +2733,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, return event; } -static struct ring_buffer_event * +static __always_inline struct ring_buffer_event * rb_reserve_next_event(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer, unsigned long length) -- cgit v1.2.3 From 929ddbf3ef4e07fef67e93e998020d49d2533724 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 11:40:34 -0500 Subject: ring-buffer: Always inline rb_event_data() The rb_event_data() is the fast path of getting the ring buffer data from an event. Externally, ring_buffer_event_data() is used to access this function. But unfortunately, rb_event_data() is not inlined, and calling ring_buffer_event_data() causes that function to be called again. Force rb_event_data() to be inlined to lower the number of operations needed when calling ring_buffer_event_data(). Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 1f3580cee6cc..2760aaca6d1b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -245,7 +245,7 @@ unsigned ring_buffer_event_length(struct ring_buffer_event *event) EXPORT_SYMBOL_GPL(ring_buffer_event_length); /* inline for ring buffer fast paths */ -static void * +static __always_inline void * rb_event_data(struct ring_buffer_event *event) { if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) -- cgit v1.2.3 From 4239174570da080f3623724d97062bf55de7e36b Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 15:52:45 -0500 Subject: tracing: Make tracepoint_printk a static_key Currently, when tracepoint_printk is set (enabled by the "tp_printk" kernel command line), it causes trace events to print via printk(). This is a very dangerous operation, but is useful for debugging. The issue is, it's seldom used, but it is always checked even if it's not enabled by the kernel command line. Instead of having this feature called by a branch against a variable, turn that variable into a static key, and this will remove the test and jump. To simplify things, the functions output_printk() and trace_event_buffer_commit() were moved from trace_events.c to trace.c. Signed-off-by: Steven Rostedt --- include/linux/ftrace.h | 4 +++ kernel/sysctl.c | 2 +- kernel/trace/trace.c | 78 +++++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace_events.c | 40 ----------------------- 4 files changed, 83 insertions(+), 41 deletions(-) (limited to 'kernel') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index b3d34d3e0e7e..8700049fd0e5 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -945,6 +945,10 @@ extern int __disable_trace_on_warning; #define INIT_TRACE_RECURSION .trace_recursion = 0, #endif +int tracepoint_printk_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); + #else /* CONFIG_TRACING */ static inline void disable_trace_on_warning(void) { } #endif /* CONFIG_TRACING */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 706309f9ed84..6ccc60dfbc7a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -634,7 +634,7 @@ static struct ctl_table kern_table[] = { .data = &tracepoint_printk, .maxlen = sizeof(tracepoint_printk), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = tracepoint_printk_sysctl, }, #endif #ifdef CONFIG_KEXEC_CORE diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 490533726b54..725e8b2c453f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -69,6 +69,7 @@ bool __read_mostly tracing_selftest_disabled; /* Pipe tracepoints to printk */ struct trace_iterator *tracepoint_print_iter; int tracepoint_printk; +static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key); /* For tracers that don't implement custom flags */ static struct tracer_opt dummy_tracer_opt[] = { @@ -2116,6 +2117,81 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, } EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); +static DEFINE_SPINLOCK(tracepoint_iter_lock); +static DEFINE_MUTEX(tracepoint_printk_mutex); + +static void output_printk(struct trace_event_buffer *fbuffer) +{ + struct trace_event_call *event_call; + struct trace_event *event; + unsigned long flags; + struct trace_iterator *iter = tracepoint_print_iter; + + /* We should never get here if iter is NULL */ + if (WARN_ON_ONCE(!iter)) + return; + + event_call = fbuffer->trace_file->event_call; + if (!event_call || !event_call->event.funcs || + !event_call->event.funcs->trace) + return; + + event = &fbuffer->trace_file->event_call->event; + + spin_lock_irqsave(&tracepoint_iter_lock, flags); + trace_seq_init(&iter->seq); + iter->ent = fbuffer->entry; + event_call->event.funcs->trace(iter, 0, event); + trace_seq_putc(&iter->seq, 0); + printk("%s", iter->seq.buffer); + + spin_unlock_irqrestore(&tracepoint_iter_lock, flags); +} + +int tracepoint_printk_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int save_tracepoint_printk; + int ret; + + mutex_lock(&tracepoint_printk_mutex); + save_tracepoint_printk = tracepoint_printk; + + ret = proc_dointvec(table, write, buffer, lenp, ppos); + + /* + * This will force exiting early, as tracepoint_printk + * is always zero when tracepoint_printk_iter is not allocated + */ + if (!tracepoint_print_iter) + tracepoint_printk = 0; + + if (save_tracepoint_printk == tracepoint_printk) + goto out; + + if (tracepoint_printk) + static_key_enable(&tracepoint_printk_key.key); + else + static_key_disable(&tracepoint_printk_key.key); + + out: + mutex_unlock(&tracepoint_printk_mutex); + + return ret; +} + +void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) +{ + if (static_key_false(&tracepoint_printk_key.key)) + output_printk(fbuffer); + + event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer, + fbuffer->event, fbuffer->entry, + fbuffer->flags, fbuffer->pc); +} +EXPORT_SYMBOL_GPL(trace_event_buffer_commit); + void trace_buffer_unlock_commit_regs(struct trace_array *tr, struct ring_buffer *buffer, struct ring_buffer_event *event, @@ -7977,6 +8053,8 @@ void __init trace_init(void) kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL); if (WARN_ON(!tracepoint_print_iter)) tracepoint_printk = 0; + else + static_key_enable(&tracepoint_printk_key.key); } tracer_alloc_buffers(); trace_event_init(); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ba67ede48822..d35fc2b0d304 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -283,46 +283,6 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, } EXPORT_SYMBOL_GPL(trace_event_buffer_reserve); -static DEFINE_SPINLOCK(tracepoint_iter_lock); - -static void output_printk(struct trace_event_buffer *fbuffer) -{ - struct trace_event_call *event_call; - struct trace_event *event; - unsigned long flags; - struct trace_iterator *iter = tracepoint_print_iter; - - if (!iter) - return; - - event_call = fbuffer->trace_file->event_call; - if (!event_call || !event_call->event.funcs || - !event_call->event.funcs->trace) - return; - - event = &fbuffer->trace_file->event_call->event; - - spin_lock_irqsave(&tracepoint_iter_lock, flags); - trace_seq_init(&iter->seq); - iter->ent = fbuffer->entry; - event_call->event.funcs->trace(iter, 0, event); - trace_seq_putc(&iter->seq, 0); - printk("%s", iter->seq.buffer); - - spin_unlock_irqrestore(&tracepoint_iter_lock, flags); -} - -void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) -{ - if (tracepoint_printk) - output_printk(fbuffer); - - event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer, - fbuffer->event, fbuffer->entry, - fbuffer->flags, fbuffer->pc); -} -EXPORT_SYMBOL_GPL(trace_event_buffer_commit); - int trace_event_reg(struct trace_event_call *call, enum trace_reg type, void *data) { -- cgit v1.2.3 From 52ffabe3848a1ebd944cdf7801a77247b1cb46d5 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 20:28:38 -0500 Subject: tracing: Make __buffer_unlock_commit() always_inline The function __buffer_unlock_commit() is called in a few places outside of trace.c. But for the most part, it should really be inlined, as it is in the hot path of the trace_events. For the callers outside of trace.c, create a new function trace_buffer_unlock_commit_nostack(), as the reason it was used was to avoid the stack tracing that trace_buffer_unlock_commit() could do. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 41 +++++++++++++++++++++++------------- kernel/trace/trace.h | 4 ++-- kernel/trace/trace_branch.c | 2 +- kernel/trace/trace_functions_graph.c | 4 ++-- kernel/trace/trace_hwlat.c | 2 +- 5 files changed, 32 insertions(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 725e8b2c453f..60416bf7c591 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -794,6 +794,22 @@ void tracing_on(void) } EXPORT_SYMBOL_GPL(tracing_on); + +static __always_inline void +__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) +{ + __this_cpu_write(trace_cmdline_save, true); + + /* If this is the temp buffer, we need to commit fully */ + if (this_cpu_read(trace_buffered_event) == event) { + /* Length is in event->array[0] */ + ring_buffer_write(buffer, event->array[0], &event->array[1]); + /* Release the temp buffer */ + this_cpu_dec(trace_buffered_event_cnt); + } else + ring_buffer_unlock_commit(buffer, event); +} + /** * __trace_puts - write a constant string into the trace buffer. * @ip: The address of the caller @@ -2059,21 +2075,6 @@ void trace_buffered_event_disable(void) preempt_enable(); } -void -__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) -{ - __this_cpu_write(trace_cmdline_save, true); - - /* If this is the temp buffer, we need to commit fully */ - if (this_cpu_read(trace_buffered_event) == event) { - /* Length is in event->array[0] */ - ring_buffer_write(buffer, event->array[0], &event->array[1]); - /* Release the temp buffer */ - this_cpu_dec(trace_buffered_event_cnt); - } else - ring_buffer_unlock_commit(buffer, event); -} - static struct ring_buffer *temp_buffer; struct ring_buffer_event * @@ -2214,6 +2215,16 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, ftrace_trace_userstack(buffer, flags, pc); } +/* + * Similar to trace_buffer_unlock_commit_regs() but do not dump stack. + */ +void +trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer, + struct ring_buffer_event *event) +{ + __buffer_unlock_commit(buffer, event); +} + static void trace_process_export(struct trace_export *export, struct ring_buffer_event *event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9294f8606ade..37602e722336 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -602,8 +602,8 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts); -void __buffer_unlock_commit(struct ring_buffer *buffer, - struct ring_buffer_event *event); +void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer, + struct ring_buffer_event *event); int trace_empty(struct trace_iterator *iter); diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 3a2a73716a5b..75489de546b6 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -81,7 +81,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) entry->correct = val == expect; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); out: current->trace_recursion &= ~TRACE_BRANCH_BIT; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 4e480e870474..8e1a115439fa 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -358,7 +358,7 @@ int __trace_graph_entry(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->graph_ent = *trace; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); return 1; } @@ -469,7 +469,7 @@ void __trace_graph_return(struct trace_array *tr, entry = ring_buffer_event_data(event); entry->ret = *trace; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); } void trace_graph_return(struct ftrace_graph_ret *trace) diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index b97286c48735..775569ec50d0 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -127,7 +127,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample) entry->nmi_count = sample->nmi_count; if (!call_filter_check_discard(call, entry, buffer, event)) - __buffer_unlock_commit(buffer, event); + trace_buffer_unlock_commit_nostack(buffer, event); } /* Macros to encapsulate the time capturing infrastructure */ -- cgit v1.2.3 From 2289d5672f99d36764cbf66e13b5401f700e7043 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 20:35:32 -0500 Subject: ring-buffer: Force inline of hotpath helper functions There's several small helper functions in ring_buffer.c that are used in the hot path. For some reason, even though they are marked inline, gcc tends not to enforce it. Make sure these functions are always inlined. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 2760aaca6d1b..04068c0ed927 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1829,48 +1829,48 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val) } EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite); -static inline void * +static __always_inline void * __rb_data_page_index(struct buffer_data_page *bpage, unsigned index) { return bpage->data + index; } -static inline void *__rb_page_index(struct buffer_page *bpage, unsigned index) +static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index) { return bpage->page->data + index; } -static inline struct ring_buffer_event * +static __always_inline struct ring_buffer_event * rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer) { return __rb_page_index(cpu_buffer->reader_page, cpu_buffer->reader_page->read); } -static inline struct ring_buffer_event * +static __always_inline struct ring_buffer_event * rb_iter_head_event(struct ring_buffer_iter *iter) { return __rb_page_index(iter->head_page, iter->head); } -static inline unsigned rb_page_commit(struct buffer_page *bpage) +static __always_inline unsigned rb_page_commit(struct buffer_page *bpage) { return local_read(&bpage->page->commit); } /* Size is determined by what has been committed */ -static inline unsigned rb_page_size(struct buffer_page *bpage) +static __always_inline unsigned rb_page_size(struct buffer_page *bpage) { return rb_page_commit(bpage); } -static inline unsigned +static __always_inline unsigned rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer) { return rb_page_commit(cpu_buffer->commit_page); } -static inline unsigned +static __always_inline unsigned rb_event_index(struct ring_buffer_event *event) { unsigned long addr = (unsigned long)event; -- cgit v1.2.3 From babe3fce95e6490b88a2a21d90eb4ba9884edb82 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 20:38:39 -0500 Subject: ring-buffer: Froce rb_update_write_stamp() to be inlined The function rb_update_write_stamp() is in the hotpath of the ring buffer recording. Make sure that it is inlined as well. There's not many places that call it. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 04068c0ed927..04579a0c7711 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2486,7 +2486,7 @@ static inline void rb_event_discard(struct ring_buffer_event *event) event->time_delta = 1; } -static inline bool +static __always_inline bool rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event) { @@ -2500,7 +2500,7 @@ rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer, rb_commit_index(cpu_buffer) == index; } -static void +static __always_inline void rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event) { -- cgit v1.2.3 From 38e11df134297ea3860c7aad8263ece27db01308 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 23 Nov 2016 20:42:31 -0500 Subject: ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline Both rb_end_commit() and rb_set_commit_to_write() are in the fast path of the ring buffer recording. Make sure they are always inlined. Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org Reported-by: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 04579a0c7711..f17476f9d7f4 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2386,7 +2386,7 @@ static void rb_start_commit(struct ring_buffer_per_cpu *cpu_buffer) local_inc(&cpu_buffer->commits); } -static void +static __always_inline void rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) { unsigned long max_count; @@ -2441,7 +2441,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) goto again; } -static inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer) +static __always_inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer) { unsigned long commits; -- cgit v1.2.3 From 8cf868affdc459beee1a941df0cfaba1673740e3 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 28 Nov 2016 13:03:21 -0500 Subject: tracing: Have the reg function allow to fail Some tracepoints have a registration function that gets enabled when the tracepoint is enabled. There may be cases that the registraction function must fail (for example, can't allocate enough memory). In this case, the tracepoint should also fail to register, otherwise the user would not know why the tracepoint is not working. Cc: David Howells Cc: Seiji Aguchi Cc: Anton Blanchard Cc: Mathieu Desnoyers Signed-off-by: Steven Rostedt --- arch/powerpc/include/asm/trace.h | 4 ++-- arch/powerpc/platforms/powernv/opal-tracepoints.c | 6 ++++-- arch/powerpc/platforms/pseries/lpar.c | 6 ++++-- arch/x86/include/asm/trace/exceptions.h | 2 +- arch/x86/include/asm/trace/irq_vectors.h | 2 +- arch/x86/kernel/tracepoint.c | 3 ++- drivers/i2c/i2c-core.c | 3 ++- include/linux/tracepoint-defs.h | 2 +- include/linux/tracepoint.h | 2 +- include/trace/events/i2c.h | 2 +- kernel/trace/trace_benchmark.c | 3 ++- kernel/trace/trace_benchmark.h | 2 +- kernel/tracepoint.c | 12 +++++++++--- samples/trace_events/trace-events-sample.c | 3 ++- samples/trace_events/trace-events-sample.h | 2 +- 15 files changed, 34 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h index 32e36b16773f..c05cef6ee06c 100644 --- a/arch/powerpc/include/asm/trace.h +++ b/arch/powerpc/include/asm/trace.h @@ -54,7 +54,7 @@ DEFINE_EVENT(ppc64_interrupt_class, timer_interrupt_exit, ); #ifdef CONFIG_PPC_PSERIES -extern void hcall_tracepoint_regfunc(void); +extern int hcall_tracepoint_regfunc(void); extern void hcall_tracepoint_unregfunc(void); TRACE_EVENT_FN_COND(hcall_entry, @@ -104,7 +104,7 @@ TRACE_EVENT_FN_COND(hcall_exit, #endif #ifdef CONFIG_PPC_POWERNV -extern void opal_tracepoint_regfunc(void); +extern int opal_tracepoint_regfunc(void); extern void opal_tracepoint_unregfunc(void); TRACE_EVENT_FN(opal_entry, diff --git a/arch/powerpc/platforms/powernv/opal-tracepoints.c b/arch/powerpc/platforms/powernv/opal-tracepoints.c index 1e496b780efd..3c447002edff 100644 --- a/arch/powerpc/platforms/powernv/opal-tracepoints.c +++ b/arch/powerpc/platforms/powernv/opal-tracepoints.c @@ -6,9 +6,10 @@ #ifdef HAVE_JUMP_LABEL struct static_key opal_tracepoint_key = STATIC_KEY_INIT; -void opal_tracepoint_regfunc(void) +int opal_tracepoint_regfunc(void) { static_key_slow_inc(&opal_tracepoint_key); + return 0; } void opal_tracepoint_unregfunc(void) @@ -25,9 +26,10 @@ void opal_tracepoint_unregfunc(void) /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ extern long opal_tracepoint_refcount; -void opal_tracepoint_regfunc(void) +int opal_tracepoint_regfunc(void) { opal_tracepoint_refcount++; + return 0; } void opal_tracepoint_unregfunc(void) diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index aa35245d8d6d..c0423ce3955c 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -661,9 +661,10 @@ EXPORT_SYMBOL(arch_free_page); #ifdef HAVE_JUMP_LABEL struct static_key hcall_tracepoint_key = STATIC_KEY_INIT; -void hcall_tracepoint_regfunc(void) +int hcall_tracepoint_regfunc(void) { static_key_slow_inc(&hcall_tracepoint_key); + return 0; } void hcall_tracepoint_unregfunc(void) @@ -680,9 +681,10 @@ void hcall_tracepoint_unregfunc(void) /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ extern long hcall_tracepoint_refcount; -void hcall_tracepoint_regfunc(void) +int hcall_tracepoint_regfunc(void) { hcall_tracepoint_refcount++; + return 0; } void hcall_tracepoint_unregfunc(void) diff --git a/arch/x86/include/asm/trace/exceptions.h b/arch/x86/include/asm/trace/exceptions.h index 2fbc66c7885b..2422b14c50a7 100644 --- a/arch/x86/include/asm/trace/exceptions.h +++ b/arch/x86/include/asm/trace/exceptions.h @@ -6,7 +6,7 @@ #include -extern void trace_irq_vector_regfunc(void); +extern int trace_irq_vector_regfunc(void); extern void trace_irq_vector_unregfunc(void); DECLARE_EVENT_CLASS(x86_exceptions, diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h index 38a09a13a9bc..32dd6a9e343c 100644 --- a/arch/x86/include/asm/trace/irq_vectors.h +++ b/arch/x86/include/asm/trace/irq_vectors.h @@ -6,7 +6,7 @@ #include -extern void trace_irq_vector_regfunc(void); +extern int trace_irq_vector_regfunc(void); extern void trace_irq_vector_unregfunc(void); DECLARE_EVENT_CLASS(x86_irq_vector, diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c index 1c113db9ed57..15515132bf0d 100644 --- a/arch/x86/kernel/tracepoint.c +++ b/arch/x86/kernel/tracepoint.c @@ -34,7 +34,7 @@ static void switch_idt(void *arg) local_irq_restore(flags); } -void trace_irq_vector_regfunc(void) +int trace_irq_vector_regfunc(void) { mutex_lock(&irq_vector_mutex); if (!trace_irq_vector_refcount) { @@ -44,6 +44,7 @@ void trace_irq_vector_regfunc(void) } trace_irq_vector_refcount++; mutex_unlock(&irq_vector_mutex); + return 0; } void trace_irq_vector_unregfunc(void) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index b432b64e307a..6a2b995d7fc4 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -77,9 +77,10 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; static bool is_registered; -void i2c_transfer_trace_reg(void) +int i2c_transfer_trace_reg(void) { static_key_slow_inc(&i2c_trace_msg); + return 0; } void i2c_transfer_trace_unreg(void) diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h index 4ac89acb6136..a03192052066 100644 --- a/include/linux/tracepoint-defs.h +++ b/include/linux/tracepoint-defs.h @@ -29,7 +29,7 @@ struct tracepoint_func { struct tracepoint { const char *name; /* Tracepoint name */ struct static_key key; - void (*regfunc)(void); + int (*regfunc)(void); void (*unregfunc)(void); struct tracepoint_func __rcu *funcs; }; diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index be586c632a0c..f72fcfe0e66a 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -81,7 +81,7 @@ static inline void tracepoint_synchronize_unregister(void) } #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS -extern void syscall_regfunc(void); +extern int syscall_regfunc(void); extern void syscall_unregfunc(void); #endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */ diff --git a/include/trace/events/i2c.h b/include/trace/events/i2c.h index fe17187df65d..4abb8eab34d3 100644 --- a/include/trace/events/i2c.h +++ b/include/trace/events/i2c.h @@ -20,7 +20,7 @@ /* * drivers/i2c/i2c-core.c */ -extern void i2c_transfer_trace_reg(void); +extern int i2c_transfer_trace_reg(void); extern void i2c_transfer_trace_unreg(void); /* diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c index 0f109c4130d3..f76d0416dd83 100644 --- a/kernel/trace/trace_benchmark.c +++ b/kernel/trace/trace_benchmark.c @@ -164,11 +164,12 @@ static int benchmark_event_kthread(void *arg) * When the benchmark tracepoint is enabled, it calls this * function and the thread that calls the tracepoint is created. */ -void trace_benchmark_reg(void) +int trace_benchmark_reg(void) { bm_event_thread = kthread_run(benchmark_event_kthread, NULL, "event_benchmark"); WARN_ON(!bm_event_thread); + return 0; } /* diff --git a/kernel/trace/trace_benchmark.h b/kernel/trace/trace_benchmark.h index 3c1df1df4e29..ebdbfc2f2a64 100644 --- a/kernel/trace/trace_benchmark.h +++ b/kernel/trace/trace_benchmark.h @@ -6,7 +6,7 @@ #include -extern void trace_benchmark_reg(void); +extern int trace_benchmark_reg(void); extern void trace_benchmark_unreg(void); #define BENCHMARK_EVENT_STRLEN 128 diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index d0639d917899..1f9a31f934a4 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -194,9 +194,13 @@ static int tracepoint_add_func(struct tracepoint *tp, struct tracepoint_func *func, int prio) { struct tracepoint_func *old, *tp_funcs; + int ret; - if (tp->regfunc && !static_key_enabled(&tp->key)) - tp->regfunc(); + if (tp->regfunc && !static_key_enabled(&tp->key)) { + ret = tp->regfunc(); + if (ret < 0) + return ret; + } tp_funcs = rcu_dereference_protected(tp->funcs, lockdep_is_held(&tracepoints_mutex)); @@ -529,7 +533,7 @@ EXPORT_SYMBOL_GPL(for_each_kernel_tracepoint); /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ static int sys_tracepoint_refcount; -void syscall_regfunc(void) +int syscall_regfunc(void) { struct task_struct *p, *t; @@ -541,6 +545,8 @@ void syscall_regfunc(void) read_unlock(&tasklist_lock); } sys_tracepoint_refcount++; + + return 0; } void syscall_unregfunc(void) diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c index 880a7d1d27d2..30e282d33d4d 100644 --- a/samples/trace_events/trace-events-sample.c +++ b/samples/trace_events/trace-events-sample.c @@ -79,7 +79,7 @@ static int simple_thread_fn(void *arg) static DEFINE_MUTEX(thread_mutex); -void foo_bar_reg(void) +int foo_bar_reg(void) { pr_info("Starting thread for foo_bar_fn\n"); /* @@ -90,6 +90,7 @@ void foo_bar_reg(void) mutex_lock(&thread_mutex); simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); mutex_unlock(&thread_mutex); + return 0; } void foo_bar_unreg(void) diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h index d6b75bb495b3..76a75ab7a608 100644 --- a/samples/trace_events/trace-events-sample.h +++ b/samples/trace_events/trace-events-sample.h @@ -354,7 +354,7 @@ TRACE_EVENT_CONDITION(foo_bar_with_cond, TP_printk("foo %s %d", __get_str(foo), __entry->bar) ); -void foo_bar_reg(void); +int foo_bar_reg(void); void foo_bar_unreg(void); /* -- cgit v1.2.3 From 1dd349ab74d278cee50fc24dc26c023f3b149642 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 28 Nov 2016 13:17:25 -0500 Subject: tracing: Do not start benchmark on boot up Trace events are enabled very early on boot up via the boot command line parameter. The benchmark tool creates a new thread to perform the trace event benchmarking. But at start up, it is called before scheduling is set up and because it creates a new thread before the init thread is created, this crashes the kernel. Have the benchmark fail to register when started via the kernel command line. Also, since the registering of a tracepoint now can handle failure cases, return -ENOMEM instead of warning if the thread cannot be created. Signed-off-by: Steven Rostedt --- kernel/trace/trace_benchmark.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c index f76d0416dd83..2bc7dc3e8ff8 100644 --- a/kernel/trace/trace_benchmark.c +++ b/kernel/trace/trace_benchmark.c @@ -166,9 +166,18 @@ static int benchmark_event_kthread(void *arg) */ int trace_benchmark_reg(void) { + if (system_state != SYSTEM_RUNNING) { + pr_warning("trace benchmark cannot be started via kernel command line\n"); + return -EBUSY; + } + bm_event_thread = kthread_run(benchmark_event_kthread, NULL, "event_benchmark"); - WARN_ON(!bm_event_thread); + if (!bm_event_thread) { + pr_warning("trace benchmark failed to create kernel thread\n"); + return -ENOMEM; + } + return 0; } @@ -183,6 +192,7 @@ void trace_benchmark_unreg(void) return; kthread_stop(bm_event_thread); + bm_event_thread = NULL; strcpy(bm_str, "START"); bm_total = 0; -- cgit v1.2.3 From 989a0a3d248192b6f5d16cc2aea95faed89bb7ce Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 28 Nov 2016 13:54:57 -0500 Subject: tracing: Have system enable return error if one of the events fail If one of the events within a system fails to enable when "1" is written to the system "enable" file, it should return an error. Note, some events may still be enabled, but the user should know that something did go wrong. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index d35fc2b0d304..93116549a284 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -702,6 +702,7 @@ __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match, struct trace_event_call *call; const char *name; int ret = -EINVAL; + int eret = 0; list_for_each_entry(file, &tr->events, list) { @@ -725,9 +726,17 @@ __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match, if (event && strcmp(event, name) != 0) continue; - ftrace_event_enable_disable(file, set); + ret = ftrace_event_enable_disable(file, set); - ret = 0; + /* + * Save the first error and return that. Some events + * may still have been enabled, but let the user + * know that something went wrong. + */ + if (ret && !eret) + eret = ret; + + ret = eret; } return ret; -- cgit v1.2.3 From 9c1f6bb8c88ab6c2779bdaf12d4f3407d336f085 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 28 Nov 2016 17:48:07 -0500 Subject: tracing: Allow benchmark to be enabled at early_initcall() The trace event start up selftests fails when the trace benchmark is enabled, because it is disabled during boot. It really only needs to be disabled before scheduling is set up, as it creates a thread. Signed-off-by: Steven Rostedt --- kernel/trace/trace_benchmark.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c index 2bc7dc3e8ff8..e3b488825ae3 100644 --- a/kernel/trace/trace_benchmark.c +++ b/kernel/trace/trace_benchmark.c @@ -21,6 +21,8 @@ static u64 bm_stddev; static unsigned int bm_avg; static unsigned int bm_std; +static bool ok_to_run; + /* * This gets called in a loop recording the time it took to write * the tracepoint. What it writes is the time statistics of the last @@ -166,7 +168,7 @@ static int benchmark_event_kthread(void *arg) */ int trace_benchmark_reg(void) { - if (system_state != SYSTEM_RUNNING) { + if (!ok_to_run) { pr_warning("trace benchmark cannot be started via kernel command line\n"); return -EBUSY; } @@ -207,3 +209,12 @@ void trace_benchmark_unreg(void) bm_avg = 0; bm_stddev = 0; } + +static __init int ok_to_run_trace_benchmark(void) +{ + ok_to_run = true; + + return 0; +} + +early_initcall(ok_to_run_trace_benchmark); -- cgit v1.2.3 From 656c7f0d2d2b3237a31b105d5ed217a65350104f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Thu, 8 Dec 2016 12:40:18 -0500 Subject: tracing: Replace kmap with copy_from_user() in trace_marker writing Instead of using get_user_pages_fast() and kmap_atomic() when writing to the trace_marker file, just allocate enough space on the ring buffer directly, and write into it via copy_from_user(). Writing into the trace_marker file use to allocate a temporary buffer to perform the copy_from_user(), as we didn't want to write into the ring buffer if the copy failed. But as a trace_marker write is suppose to be extremely fast, and allocating memory causes other tracepoints to trigger, Peter Zijlstra suggested using get_user_pages_fast() and kmap_atomic() to keep the user space pages in memory and reading it directly. But Henrik Austad had issues with this because it required taking the mm->mmap_sem and causing long delays with the write. Instead, just allocate the space in the ring buffer and use copy_from_user() directly. If it faults, return -EFAULT and write "" into the ring buffer. Link: http://lkml.kernel.org/r/20161208124018.72dd0f86@gandalf.local.home Cc: Ingo Molnar Cc: Henrik Austad Cc: Peter Zijlstra Updates: d696b58ca2c3ca "tracing: Do not allocate buffer for trace_marker" Suggested-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 139 ++++++++++++++------------------------------------- 1 file changed, 37 insertions(+), 102 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 60416bf7c591..6f420d7b703b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5738,61 +5738,6 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp) return 0; } -static inline int lock_user_pages(const char __user *ubuf, size_t cnt, - struct page **pages, void **map_page, - int *offset) -{ - unsigned long addr = (unsigned long)ubuf; - int nr_pages = 1; - int ret; - int i; - - /* - * Userspace is injecting traces into the kernel trace buffer. - * We want to be as non intrusive as possible. - * To do so, we do not want to allocate any special buffers - * or take any locks, but instead write the userspace data - * straight into the ring buffer. - * - * First we need to pin the userspace buffer into memory, - * which, most likely it is, because it just referenced it. - * But there's no guarantee that it is. By using get_user_pages_fast() - * and kmap_atomic/kunmap_atomic() we can get access to the - * pages directly. We then write the data directly into the - * ring buffer. - */ - - /* check if we cross pages */ - if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) - nr_pages = 2; - - *offset = addr & (PAGE_SIZE - 1); - addr &= PAGE_MASK; - - ret = get_user_pages_fast(addr, nr_pages, 0, pages); - if (ret < nr_pages) { - while (--ret >= 0) - put_page(pages[ret]); - return -EFAULT; - } - - for (i = 0; i < nr_pages; i++) - map_page[i] = kmap_atomic(pages[i]); - - return nr_pages; -} - -static inline void unlock_user_pages(struct page **pages, - void **map_page, int nr_pages) -{ - int i; - - for (i = nr_pages - 1; i >= 0; i--) { - kunmap_atomic(map_page[i]); - put_page(pages[i]); - } -} - static ssize_t tracing_mark_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *fpos) @@ -5802,14 +5747,14 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, struct ring_buffer *buffer; struct print_entry *entry; unsigned long irq_flags; - struct page *pages[2]; - void *map_page[2]; - int nr_pages = 1; + const char faulted[] = ""; ssize_t written; - int offset; int size; int len; +/* Used in tracing_mark_raw_write() as well */ +#define FAULTED_SIZE (sizeof(faulted) - 1) /* '\0' is already accounted for */ + if (tracing_disabled) return -EINVAL; @@ -5821,30 +5766,31 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); - nr_pages = lock_user_pages(ubuf, cnt, pages, map_page, &offset); - if (nr_pages < 0) - return nr_pages; - local_save_flags(irq_flags); - size = sizeof(*entry) + cnt + 2; /* possible \n added */ + size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */ + + /* If less than "", then make sure we can still add that */ + if (cnt < FAULTED_SIZE) + size += FAULTED_SIZE - cnt; + buffer = tr->trace_buffer.buffer; event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, irq_flags, preempt_count()); - if (!event) { + if (unlikely(!event)) /* Ring buffer disabled, return as if not open for write */ - written = -EBADF; - goto out_unlock; - } + return -EBADF; entry = ring_buffer_event_data(event); entry->ip = _THIS_IP_; - if (nr_pages == 2) { - len = PAGE_SIZE - offset; - memcpy(&entry->buf, map_page[0] + offset, len); - memcpy(&entry->buf[len], map_page[1], cnt - len); + len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt); + if (len) { + memcpy(&entry->buf, faulted, FAULTED_SIZE); + cnt = FAULTED_SIZE; + written = -EFAULT; } else - memcpy(&entry->buf, map_page[0] + offset, cnt); + written = cnt; + len = cnt; if (entry->buf[cnt - 1] != '\n') { entry->buf[cnt] = '\n'; @@ -5854,12 +5800,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, __buffer_unlock_commit(buffer, event); - written = cnt; - - *fpos += written; - - out_unlock: - unlock_user_pages(pages, map_page, nr_pages); + if (written > 0) + *fpos += written; return written; } @@ -5875,15 +5817,14 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf, struct ring_buffer_event *event; struct ring_buffer *buffer; struct raw_data_entry *entry; + const char faulted[] = ""; unsigned long irq_flags; - struct page *pages[2]; - void *map_page[2]; - int nr_pages = 1; ssize_t written; - int offset; int size; int len; +#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int)) + if (tracing_disabled) return -EINVAL; @@ -5899,38 +5840,32 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf, BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); - nr_pages = lock_user_pages(ubuf, cnt, pages, map_page, &offset); - if (nr_pages < 0) - return nr_pages; - local_save_flags(irq_flags); size = sizeof(*entry) + cnt; + if (cnt < FAULT_SIZE_ID) + size += FAULT_SIZE_ID - cnt; + buffer = tr->trace_buffer.buffer; event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, irq_flags, preempt_count()); - if (!event) { + if (!event) /* Ring buffer disabled, return as if not open for write */ - written = -EBADF; - goto out_unlock; - } + return -EBADF; entry = ring_buffer_event_data(event); - if (nr_pages == 2) { - len = PAGE_SIZE - offset; - memcpy(&entry->id, map_page[0] + offset, len); - memcpy(((char *)&entry->id) + len, map_page[1], cnt - len); + len = __copy_from_user_inatomic(&entry->id, ubuf, cnt); + if (len) { + entry->id = -1; + memcpy(&entry->buf, faulted, FAULTED_SIZE); + written = -EFAULT; } else - memcpy(&entry->id, map_page[0] + offset, cnt); + written = cnt; __buffer_unlock_commit(buffer, event); - written = cnt; - - *fpos += written; - - out_unlock: - unlock_user_pages(pages, map_page, nr_pages); + if (written > 0) + *fpos += written; return written; } -- cgit v1.2.3 From 794de08a16cf1fc1bf785dc48f66d36218cf6d88 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Thu, 8 Dec 2016 20:54:49 -0500 Subject: fgraph: Handle a case where a tracer ignores set_graph_notrace Both the wakeup and irqsoff tracers can use the function graph tracer when the display-graph option is set. The problem is that they ignore the notrace file, and record the entry of functions that would be ignored by the function_graph tracer. This causes the trace->depth to be recorded into the ring buffer. The set_graph_notrace uses a trick by adding a large negative number to the trace->depth when a graph function is to be ignored. On trace output, the graph function uses the depth to record a stack of functions. But since the depth is negative, it accesses the array with a negative number and causes an out of bounds access that can cause a kernel oops or corrupt data. Have the print functions handle cases where a tracer still records functions even when they are in set_graph_notrace. Also add warnings if the depth is below zero before accessing the array. Note, the function graph logic will still prevent the return of these functions from being recorded, which means that they will be left hanging without a return. For example: # echo '*spin*' > set_graph_notrace # echo 1 > options/display-graph # echo wakeup > current_tracer # cat trace [...] _raw_spin_lock() { preempt_count_add() { do_raw_spin_lock() { update_rq_clock(); Where it should look like: _raw_spin_lock() { preempt_count_add(); do_raw_spin_lock(); } update_rq_clock(); Cc: stable@vger.kernel.org Cc: Namhyung Kim Fixes: 29ad23b00474 ("ftrace: Add set_graph_notrace filter") Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 8e1a115439fa..566f7327c3aa 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -842,6 +842,10 @@ print_graph_entry_leaf(struct trace_iterator *iter, cpu_data = per_cpu_ptr(data->cpu_data, cpu); + /* If a graph tracer ignored set_graph_notrace */ + if (call->depth < -1) + call->depth += FTRACE_NOTRACE_DEPTH; + /* * Comments display at + 1 to depth. Since * this is a leaf function, keep the comments @@ -850,7 +854,8 @@ print_graph_entry_leaf(struct trace_iterator *iter, cpu_data->depth = call->depth - 1; /* No need to keep this function around for this depth */ - if (call->depth < FTRACE_RETFUNC_DEPTH) + if (call->depth < FTRACE_RETFUNC_DEPTH && + !WARN_ON_ONCE(call->depth < 0)) cpu_data->enter_funcs[call->depth] = 0; } @@ -880,11 +885,16 @@ print_graph_entry_nested(struct trace_iterator *iter, struct fgraph_cpu_data *cpu_data; int cpu = iter->cpu; + /* If a graph tracer ignored set_graph_notrace */ + if (call->depth < -1) + call->depth += FTRACE_NOTRACE_DEPTH; + cpu_data = per_cpu_ptr(data->cpu_data, cpu); cpu_data->depth = call->depth; /* Save this function pointer to see if the exit matches */ - if (call->depth < FTRACE_RETFUNC_DEPTH) + if (call->depth < FTRACE_RETFUNC_DEPTH && + !WARN_ON_ONCE(call->depth < 0)) cpu_data->enter_funcs[call->depth] = call->func; } @@ -1114,7 +1124,8 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, */ cpu_data->depth = trace->depth - 1; - if (trace->depth < FTRACE_RETFUNC_DEPTH) { + if (trace->depth < FTRACE_RETFUNC_DEPTH && + !WARN_ON_ONCE(trace->depth < 0)) { if (cpu_data->enter_funcs[trace->depth] != trace->func) func_match = 0; cpu_data->enter_funcs[trace->depth] = 0; -- cgit v1.2.3 From 1a41442864e35bff859582fe9c5d051d0b1040ba Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Thu, 8 Dec 2016 19:28:28 -0500 Subject: tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too Currently both the wakeup and irqsoff traces do not handle set_graph_notrace well. The ftrace infrastructure will ignore the return paths of all functions leaving them hanging without an end: # echo '*spin*' > set_graph_notrace # cat trace [...] _raw_spin_lock() { preempt_count_add() { do_raw_spin_lock() { update_rq_clock(); Where the '*spin*' functions should have looked like this: _raw_spin_lock() { preempt_count_add(); do_raw_spin_lock(); } update_rq_clock(); Instead, have the wakeup and irqsoff tracers ignore the functions that are set by the set_graph_notrace like the function_graph tracer does. Move the logic in the function_graph tracer into a header to allow wakeup and irqsoff tracers to use it as well. Cc: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 11 +++++++++++ kernel/trace/trace_functions_graph.c | 14 +++++++------- kernel/trace/trace_irqsoff.c | 12 ++++++++++++ kernel/trace/trace_sched_wakeup.c | 12 ++++++++++++ 4 files changed, 42 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 37602e722336..c2234494f40c 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -846,6 +846,17 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr) return 0; } #endif /* CONFIG_DYNAMIC_FTRACE */ + +extern unsigned int fgraph_max_depth; + +static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace) +{ + /* trace it when it is-nested-in or is a function enabled. */ + return !(trace->depth || ftrace_graph_addr(trace->func)) || + (trace->depth < 0) || + (fgraph_max_depth && trace->depth >= fgraph_max_depth); +} + #else /* CONFIG_FUNCTION_GRAPH_TRACER */ static inline enum print_line_t print_graph_function_flags(struct trace_iterator *iter, u32 flags) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 566f7327c3aa..d56123cdcc89 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -65,7 +65,7 @@ struct fgraph_data { #define TRACE_GRAPH_INDENT 2 -static unsigned int max_depth; +unsigned int fgraph_max_depth; static struct tracer_opt trace_opts[] = { /* Display overruns? (for self-debug purpose) */ @@ -384,10 +384,10 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) if (!ftrace_trace_task(tr)) return 0; - /* trace it when it is-nested-in or is a function enabled. */ - if ((!(trace->depth || ftrace_graph_addr(trace->func)) || - ftrace_graph_ignore_irqs()) || (trace->depth < 0) || - (max_depth && trace->depth >= max_depth)) + if (ftrace_graph_ignore_func(trace)) + return 0; + + if (ftrace_graph_ignore_irqs()) return 0; /* @@ -1500,7 +1500,7 @@ graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, if (ret) return ret; - max_depth = val; + fgraph_max_depth = val; *ppos += cnt; @@ -1514,7 +1514,7 @@ graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/ int n; - n = sprintf(buf, "%d\n", max_depth); + n = sprintf(buf, "%d\n", fgraph_max_depth); return simple_read_from_buffer(ubuf, cnt, ppos, buf, n); } diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 03cdff84d026..86654d7e1afe 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -175,6 +175,18 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) int ret; int pc; + if (ftrace_graph_ignore_func(trace)) + return 0; + /* + * Do not trace a function if it's filtered by set_graph_notrace. + * Make the index of ret stack negative to indicate that it should + * ignore further functions. But it needs its own ret stack entry + * to recover the original index in order to continue tracing after + * returning from the function. + */ + if (ftrace_graph_notrace_addr(trace->func)) + return 1; + if (!func_prolog_dec(tr, &data, &flags)) return 0; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 1bf2324dc682..5d0bb025bb21 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -239,6 +239,18 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace) unsigned long flags; int pc, ret = 0; + if (ftrace_graph_ignore_func(trace)) + return 0; + /* + * Do not trace a function if it's filtered by set_graph_notrace. + * Make the index of ret stack negative to indicate that it should + * ignore further functions. But it needs its own ret stack entry + * to recover the original index in order to continue tracing after + * returning from the function. + */ + if (ftrace_graph_notrace_addr(trace->func)) + return 1; + if (!func_prolog_preempt_disable(tr, &data, &pc)) return 0; -- cgit v1.2.3 From c59f29cb144a6a0dfac16ede9dc8eafc02dc56ca Mon Sep 17 00:00:00 2001 From: Pavankumar Kondeti Date: Fri, 9 Dec 2016 21:50:17 +0530 Subject: tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results The 's' flag is supposed to indicate that a softirq is running. This can be detected by testing the preempt_count with SOFTIRQ_OFFSET. The current code tests the preempt_count with SOFTIRQ_MASK, which would be true even when softirqs are disabled but not serving a softirq. Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org Signed-off-by: Pavankumar Kondeti Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6f420d7b703b..970aafe80b49 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1949,7 +1949,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, #endif ((pc & NMI_MASK ) ? TRACE_FLAG_NMI : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | - ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | + ((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) | (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); } -- cgit v1.2.3 From 99e6f6e8134b0c9d5d82eb2af1068a57199125e4 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 7 Dec 2016 14:31:33 +0100 Subject: tracing/rb: Init the CPU mask on allocation Before commit b32614c03413 ("tracing/rb: Convert to hotplug state machine") the allocated cpumask was initialized to the mask of ONLINE or POSSIBLE CPUs. After the CPU hotplug changes the buffer initialisation moved to trace_rb_cpu_prepare() but I forgot to initially set the cpumask to zero. This is done now. Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de Fixes: b32614c03413 ("tracing/rb: Convert to hotplug state machine") Reported-by: Tetsuo Handa Tested-by: Tetsuo Handa Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index f17476f9d7f4..7edfd41d506c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1303,7 +1303,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, if (!buffer) return NULL; - if (!alloc_cpumask_var(&buffer->cpumask, GFP_KERNEL)) + if (!zalloc_cpumask_var(&buffer->cpumask, GFP_KERNEL)) goto fail_free_buffer; nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); -- cgit v1.2.3 From f18f97ac43d72ae84fe012dd4f19fe3f8f901469 Mon Sep 17 00:00:00 2001 From: Marcin Nowakowski Date: Fri, 9 Dec 2016 15:19:37 +0100 Subject: tracing/kprobes: Add a helper method to return number of probe hits The number of probe hits is stored in a percpu variable and therefore can't be read directly. Add a helper method trace_kprobe_nhit() that performs the required calculation. It will be used in a follow-up commit that changes kprobe selftests to verify the number of probe hits. Link: http://lkml.kernel.org/r/1481293178-3128-1-git-send-email-marcin.nowakowski@imgtec.com Acked-by: Masami Hiramatsu Signed-off-by: Marcin Nowakowski Signed-off-by: Steven Rostedt --- kernel/trace/trace_kprobe.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index eb6c9f1d3a93..a2af1bceca29 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -73,6 +73,17 @@ static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) return !!strchr(trace_kprobe_symbol(tk), ':'); } +static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) +{ + unsigned long nhit = 0; + int cpu; + + for_each_possible_cpu(cpu) + nhit += *per_cpu_ptr(tk->nhit, cpu); + + return nhit; +} + static int register_kprobe_event(struct trace_kprobe *tk); static int unregister_kprobe_event(struct trace_kprobe *tk); @@ -882,14 +893,10 @@ static const struct file_operations kprobe_events_ops = { static int probes_profile_seq_show(struct seq_file *m, void *v) { struct trace_kprobe *tk = v; - unsigned long nhit = 0; - int cpu; - - for_each_possible_cpu(cpu) - nhit += *per_cpu_ptr(tk->nhit, cpu); seq_printf(m, " %-44s %15lu %15lu\n", - trace_event_name(&tk->tp.call), nhit, + trace_event_name(&tk->tp.call), + trace_kprobe_nhit(tk), tk->rp.kp.nmissed); return 0; -- cgit v1.2.3 From d4d7ccc834fe2401084e01fb043ad70ac410b19d Mon Sep 17 00:00:00 2001 From: Marcin Nowakowski Date: Fri, 9 Dec 2016 15:19:38 +0100 Subject: kprobes/trace: Fix kprobe selftest for newer gcc Commit 265a5b7ee3eb ("kprobes/trace: Fix kprobe selftest for gcc 4.6") has added __used attribute to kprobe_trace_selftest_target to ensure that the method is listed in kallsyms table. However, even though the method remains in the kernel image, the actual call is optimized away as there are no side effects and the return value is never checked. Add a return value check and a 'noinline' attribute to ensure that an inlined copy of the method is not used by the caller. Also add checks that verify that the kprobe was really hit, as at the moment the tests show positive results despite the test method being optimized away. Finally, add __init annotations to find_trace_probe_file() and kprobe_trace_selftest_target() as they are only called from within an __init method. Link: http://lkml.kernel.org/r/1481293178-3128-2-git-send-email-marcin.nowakowski@imgtec.com Acked-by: Masami Hiramatsu Signed-off-by: Marcin Nowakowski Signed-off-by: Steven Rostedt --- kernel/trace/trace_kprobe.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a2af1bceca29..a133ecd741e4 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1361,18 +1361,18 @@ fs_initcall(init_kprobe_trace); #ifdef CONFIG_FTRACE_STARTUP_TEST - /* * The "__used" keeps gcc from removing the function symbol - * from the kallsyms table. + * from the kallsyms table. 'noinline' makes sure that there + * isn't an inlined version used by the test method below */ -static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, - int a4, int a5, int a6) +static __used __init noinline int +kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6) { return a1 + a2 + a3 + a4 + a5 + a6; } -static struct trace_event_file * +static struct __init trace_event_file * find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) { struct trace_event_file *file; @@ -1450,12 +1450,25 @@ static __init int kprobe_trace_self_tests_init(void) ret = target(1, 2, 3, 4, 5, 6); + /* + * Not expecting an error here, the check is only to prevent the + * optimizer from removing the call to target() as otherwise there + * are no side-effects and the call is never performed. + */ + if (ret != 21) + warn++; + /* Disable trace points before removing it */ tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); if (WARN_ON_ONCE(tk == NULL)) { pr_warn("error on getting test probe.\n"); warn++; } else { + if (trace_kprobe_nhit(tk) != 1) { + pr_warn("incorrect number of testprobe hits\n"); + warn++; + } + file = find_trace_probe_file(tk, top_trace_array()); if (WARN_ON_ONCE(file == NULL)) { pr_warn("error on getting probe file.\n"); @@ -1469,6 +1482,11 @@ static __init int kprobe_trace_self_tests_init(void) pr_warn("error on getting 2nd test probe.\n"); warn++; } else { + if (trace_kprobe_nhit(tk) != 1) { + pr_warn("incorrect number of testprobe2 hits\n"); + warn++; + } + file = find_trace_probe_file(tk, top_trace_array()); if (WARN_ON_ONCE(file == NULL)) { pr_warn("error on getting probe file.\n"); -- cgit v1.2.3