From 4fead8e46fded93cc0d432ced774d9a3a8d21bad Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Mon, 14 Sep 2009 16:49:12 -0400 Subject: [PATCH] ftrace: Fix trace_remove_event_call() to lock trace_event_mutex Lock not only event_mutex but also trace_event_mutex in trace_remove_event_call() to protect __unregister_ftrace_event(). Signed-off-by: Masami Hiramatsu Acked-by: Steven Rostedt Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Tom Zanussi LKML-Reference: <20090914204912.18779.68734.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker --- kernel/trace/trace_events.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 83cc2c01195d..f85b0f1cb942 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1054,6 +1054,9 @@ static void remove_subsystem_dir(const char *name) } } +/* + * Must be called under locking both of event_mutex and trace_event_mutex. + */ static void __trace_remove_event_call(struct ftrace_event_call *call) { ftrace_event_enable_disable(call, 0); @@ -1070,7 +1073,9 @@ static void __trace_remove_event_call(struct ftrace_event_call *call) void trace_remove_event_call(struct ftrace_event_call *call) { mutex_lock(&event_mutex); + down_write(&trace_event_mutex); __trace_remove_event_call(call); + up_write(&trace_event_mutex); mutex_unlock(&event_mutex); }