linux_dsm_epyc7002/kernel/trace/trace_event_profile.c
Li Zefan 558e6547e4 tracing/profile: fix profile_disable vs module_unload
If the correspoding module is unloaded before ftrace_profile_disable()
is called, event->profile_disable() won't be called, which can
cause oops:

  # insmod trace-events-sample.ko
  # perf record -f -a -e sample:foo_bar sleep 3 &
  # sleep 1
  # rmmod trace_events_sample
  # insmod trace-events-sample.ko
  OOPS!

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A9214E3.2070807@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-12 22:28:38 -04:00

43 lines
844 B
C

/*
* trace event based perf counter profiling
*
* Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com>
*
*/
#include <linux/module.h>
#include "trace.h"
int ftrace_profile_enable(int event_id)
{
struct ftrace_event_call *event;
int ret = -EINVAL;
mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
if (event->id == event_id && event->profile_enable &&
try_module_get(event->mod)) {
ret = event->profile_enable(event);
break;
}
}
mutex_unlock(&event_mutex);
return ret;
}
void ftrace_profile_disable(int event_id)
{
struct ftrace_event_call *event;
mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
if (event->id == event_id) {
event->profile_disable(event);
module_put(event->mod);
break;
}
}
mutex_unlock(&event_mutex);
}