From 75e8387685f6c65feb195a4556110b58f852b848 Mon Sep 17 00:00:00 2001 From: Zhou Chengming Date: Fri, 25 Aug 2017 21:49:37 +0800 Subject: [PATCH] perf/ftrace: Fix double traces of perf on ftrace:function When running perf on the ftrace:function tracepoint, there is a bug which can be reproduced by: perf record -e ftrace:function -a sleep 20 & perf record -e ftrace:function ls perf script ls 10304 [005] 171.853235: ftrace:function: perf_output_begin ls 10304 [005] 171.853237: ftrace:function: perf_output_begin ls 10304 [005] 171.853239: ftrace:function: task_tgid_nr_ns ls 10304 [005] 171.853240: ftrace:function: task_tgid_nr_ns ls 10304 [005] 171.853242: ftrace:function: __task_pid_nr_ns ls 10304 [005] 171.853244: ftrace:function: __task_pid_nr_ns We can see that all the function traces are doubled. The problem is caused by the inconsistency of the register function perf_ftrace_event_register() with the probe function perf_ftrace_function_call(). The former registers one probe for every perf_event. And the latter handles all perf_events on the current cpu. So when two perf_events on the current cpu, the traces of them will be doubled. So this patch adds an extra parameter "event" for perf_tp_event, only send sample data to this event when it's not NULL. Signed-off-by: Zhou Chengming Reviewed-by: Jiri Olsa Acked-by: Steven Rostedt (VMware) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: huawei.libin@huawei.com Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 2 +- include/linux/trace_events.h | 4 ++-- kernel/events/core.c | 13 +++++++++---- kernel/trace/trace_event_perf.c | 4 +++- kernel/trace/trace_kprobe.c | 4 ++-- kernel/trace/trace_syscalls.c | 4 ++-- kernel/trace/trace_uprobe.c | 2 +- 7 files changed, 20 insertions(+), 13 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b14095bcf4bb..c00cd4b02f32 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1201,7 +1201,7 @@ extern void perf_event_init(void); extern void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, - struct task_struct *task); + struct task_struct *task, struct perf_event *event); extern void perf_bp_event(struct perf_event *event, void *data); #ifndef perf_misc_flags diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 536c80ff7ad9..5012b524283d 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -508,9 +508,9 @@ void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, static inline void perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type, u64 count, struct pt_regs *regs, void *head, - struct task_struct *task) + struct task_struct *task, struct perf_event *event) { - perf_tp_event(type, count, raw_data, size, regs, head, rctx, task); + perf_tp_event(type, count, raw_data, size, regs, head, rctx, task, event); } #endif diff --git a/kernel/events/core.c b/kernel/events/core.c index ce131d25622a..03ac9c8b02fb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7906,16 +7906,15 @@ void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, } } perf_tp_event(call->event.type, count, raw_data, size, regs, head, - rctx, task); + rctx, task, NULL); } EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit); void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, - struct task_struct *task) + struct task_struct *task, struct perf_event *event) { struct perf_sample_data data; - struct perf_event *event; struct perf_raw_record raw = { .frag = { @@ -7929,9 +7928,15 @@ void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, perf_trace_buf_update(record, event_type); - hlist_for_each_entry_rcu(event, head, hlist_entry) { + /* Use the given event instead of the hlist */ + if (event) { if (perf_tp_event_match(event, &data, regs)) perf_swevent_event(event, count, &data, regs); + } else { + hlist_for_each_entry_rcu(event, head, hlist_entry) { + if (perf_tp_event_match(event, &data, regs)) + perf_swevent_event(event, count, &data, regs); + } } /* diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 562fa69df5d3..13ba2d3f6a91 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -306,6 +306,7 @@ static void perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *pt_regs) { + struct perf_event *event; struct ftrace_entry *entry; struct hlist_head *head; struct pt_regs regs; @@ -329,8 +330,9 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, entry->ip = ip; entry->parent_ip = parent_ip; + event = container_of(ops, struct perf_event, ftrace_ops); perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, TRACE_FN, - 1, ®s, head, NULL); + 1, ®s, head, NULL, event); #undef ENTRY_SIZE } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index c9b5aa10fbf9..8a907e12b6b9 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1200,7 +1200,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) memset(&entry[1], 0, dsize); store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, - head, NULL); + head, NULL, NULL); } NOKPROBE_SYMBOL(kprobe_perf_func); @@ -1236,7 +1236,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, entry->ret_ip = (unsigned long)ri->ret_addr; store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, - head, NULL); + head, NULL, NULL); } NOKPROBE_SYMBOL(kretprobe_perf_func); #endif /* CONFIG_PERF_EVENTS */ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 5e10395da88e..74d9a86eccc0 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -596,7 +596,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) (unsigned long *)&rec->args); perf_trace_buf_submit(rec, size, rctx, sys_data->enter_event->event.type, 1, regs, - head, NULL); + head, NULL, NULL); } static int perf_sysenter_enable(struct trace_event_call *call) @@ -667,7 +667,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) rec->nr = syscall_nr; rec->ret = syscall_get_return_value(current, regs); perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type, - 1, regs, head, NULL); + 1, regs, head, NULL, NULL); } static int perf_sysexit_enable(struct trace_event_call *call) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index a7581fec9681..4525e0271a53 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1156,7 +1156,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, } perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, - head, NULL); + head, NULL, NULL); out: preempt_enable(); } -- 2.30.2