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From: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
To: rostedt@goodmis.org
Cc: masami.hiramatsu.pt@hitachi.com,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org, yrl.pp-manager.tt@hitachi.com
Subject: [PATCH v3 -tip 1/4] tracing: add checks if tr->buffer is NULL in tracing_reset{_online_cpus}
Date: Wed, 19 Dec 2012 16:02:34 +0900	[thread overview]
Message-ID: <20121219070234.31200.93863.stgit@liselsia> (raw)
In-Reply-To: <20121219070218.31200.64647.stgit@liselsia>

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.

Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
 kernel/trace/trace.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c705c7a..a8ce008 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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 */


  reply	other threads:[~2012-12-19  7:03 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-19  7:02 [PATCH v3 -tip 0/4] tracing: make a snapshot feature available from userspace Hiraku Toyooka
2012-12-19  7:02 ` Hiraku Toyooka [this message]
2013-01-24 19:39   ` [tip:perf/core] tracing: Add checks if tr-> buffer is NULL in tracing_reset{_online_cpus} tip-bot for Hiraku Toyooka
2012-12-19  7:02 ` [PATCH v3 -tip 2/4] tracing: replace static old_tracer with strcmp Hiraku Toyooka
2012-12-21  3:04   ` Steven Rostedt
2012-12-21 10:55     ` Hiraku Toyooka
2012-12-19  7:02 ` [PATCH v3 -tip 3/4] tracing: make a snapshot feature available from userspace Hiraku Toyooka
2012-12-19  7:02 ` [PATCH v3 -tip 4/4] tracing: add description of snapshot to Documentation/trace/ftrace.txt Hiraku Toyooka

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