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Commit 11a241a3 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

tracing: add protection around modify trace event fields 



The trace event objects are currently not proctected against
reentrancy. This patch adds a mutex around the modifications of
the trace event fields.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent d20e3b03

kernel/trace/trace_events.c

+7 −0
Original line number Original line Diff line number Diff line
@@ -14,6 +14,8 @@ 




#define TRACE_SYSTEM "TRACE_SYSTEM"

#define TRACE_SYSTEM "TRACE_SYSTEM"





static DEFINE_MUTEX(event_mutex);



#define events_for_each(event)						\

#define events_for_each(event)						\

	for (event = __start_ftrace_events;				\

	for (event = __start_ftrace_events;				\

	     (unsigned long)event < (unsigned long)__stop_ftrace_events; \

	     (unsigned long)event < (unsigned long)__stop_ftrace_events; \
@@ -104,6 +106,7 @@ static int ftrace_set_clr_event(char *buf, int set) 
			event = NULL;

			event = NULL;

	}

	}





	mutex_lock(&event_mutex);

	events_for_each(call) {

	events_for_each(call) {





		if (!call->name)

		if (!call->name)
@@ -124,6 +127,8 @@ static int ftrace_set_clr_event(char *buf, int set) 




		ret = 0;

		ret = 0;

	}

	}

	mutex_unlock(&event_mutex);



	return ret;

	return ret;

}

}
@@ -324,7 +329,9 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 
	switch (val) {

	switch (val) {

	case 0:

	case 0:

	case 1:

	case 1:

		mutex_lock(&event_mutex);

		ftrace_event_enable_disable(call, val);

		ftrace_event_enable_disable(call, val);

		mutex_unlock(&event_mutex);

		break;

		break;





	default:

	default: