Commit 75e83876 authored by Zhou Chengming's avatar Zhou Chengming Committed by Ingo Molnar

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: default avatarZhou Chengming <zhouchengming1@huawei.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent f12f42ac
......@@ -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
......
......@@ -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
......
......@@ -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);
}
}
/*
......
......@@ -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, &regs, head, NULL);
1, &regs, head, NULL, event);
#undef ENTRY_SIZE
}
......
......@@ -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 */
......
......@@ -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)
......
......@@ -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();
}
......
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