Commit a5416411 authored Dec 19, 2012 by Hiraku Toyooka Committed by Steven Rostedt Jan 21, 2013

tracing: Add checks if tr->buffer is NULL in tracing_reset{_online_cpus}

max_tr->buffer could be NULL in the tracing_reset{_online_cpus}. In this
case, a NULL pointer dereference happens, so we should return immediately
from these functions.

Note, the current code does not call tracing_reset*() with max_tr when
its buffer is NULL, but future code will. This patch is needed to prevent
the future code from crashing.

Link: http://lkml.kernel.org/r/20121219070234.31200.93863.stgit@liselsia



Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 6aea49cb

kernel/trace/trace.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -922,6 +922,9 @@ void tracing_reset(struct trace_array *tr, int cpu)
		{
		struct ring_buffer *buffer = tr->buffer;

		if (!buffer)
		return;

		ring_buffer_record_disable(buffer);

		/* Make sure all commits have finished */
		@@ -936,6 +939,9 @@ void tracing_reset_online_cpus(struct trace_array *tr)
		struct ring_buffer *buffer = tr->buffer;
		int cpu;

		if (!buffer)
		return;

		ring_buffer_record_disable(buffer);

		/* Make sure all commits have finished */