Commit d15f57f2 authored May 12, 2008 by Steven Rostedt Committed by Thomas Gleixner May 23, 2008

ftrace: fix mutex unlock in trace output



If the trace output changes on reading the trace files, there is a chance
that the start function will return NULL. If the start function of a sequence
returns NULL the stop equivalent is not called. In this case, all locks
that are taken must be released even if they are released in the stop function.

This patch fixes a case that a mutex was not released on return of NULL
in the start sequence function.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 07a267cd

kernel/trace/trace.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -964,8 +964,10 @@ static void s_start(struct seq_file m, loff_t *pos)

		mutex_lock(&trace_types_lock);

		if (!current_trace \|\| current_trace != iter->trace)
		if (!current_trace \|\| current_trace != iter->trace) {
		mutex_unlock(&trace_types_lock);
		return NULL;
		}

		atomic_inc(&trace_record_cmdline_disabled);

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