From 11a241a3302277db05561e01477528629d806c4e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 2 Mar 2009 11:49:04 -0500 Subject: [PATCH] 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: Steven Rostedt --- kernel/trace/trace_events.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 1d07f800a9ce..26069fa6b3b0 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -14,6 +14,8 @@ #define TRACE_SYSTEM "TRACE_SYSTEM" +static DEFINE_MUTEX(event_mutex); + #define events_for_each(event) \ for (event = __start_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; } + mutex_lock(&event_mutex); events_for_each(call) { if (!call->name) @@ -124,6 +127,8 @@ static int ftrace_set_clr_event(char *buf, int set) ret = 0; } + mutex_unlock(&event_mutex); + return ret; } @@ -324,7 +329,9 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, switch (val) { case 0: case 1: + mutex_lock(&event_mutex); ftrace_event_enable_disable(call, val); + mutex_unlock(&event_mutex); break; default: -- 2.39.2