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From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org
Cc: akpm@linux-foundation.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
	Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: [patch 09/16] Tracepoint fix disable
Date: Fri, 14 Nov 2008 17:47:42 -0500	[thread overview]
Message-ID: <20081114224948.632083242@polymtl.ca> (raw)
In-Reply-To: 20081114224733.364965865@polymtl.ca

[-- Attachment #1: tracepoint-fix-disable.patch --]
[-- Type: text/plain, Size: 972 bytes --]

Set the probe array pointer to NULL when the tracepoint is disabled.
The probe array point not being NULL could generate a race condition where the
reader would dereference a freed pointer.

Impact: bugfix.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: 'Ingo Molnar' <mingo@elte.hu>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
---
 kernel/tracepoint.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux.trees.git/kernel/tracepoint.c
===================================================================
--- linux.trees.git.orig/kernel/tracepoint.c	2008-11-14 17:39:52.000000000 -0500
+++ linux.trees.git/kernel/tracepoint.c	2008-11-14 17:39:56.000000000 -0500
@@ -262,6 +262,7 @@ static void set_tracepoint(struct tracep
 static void disable_tracepoint(struct tracepoint *elem)
 {
 	elem->state = 0;
+	rcu_assign_pointer(elem->funcs, NULL);
 }
 
 /**

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

  parent reply	other threads:[~2008-11-14 23:00 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-14 22:47 [patch 00/16] Markers and Tracepoints Updates for -tip Mathieu Desnoyers
2008-11-14 22:47 ` [patch 01/16] RCU read sched notrace Mathieu Desnoyers
2008-11-16  4:00   ` Paul E. McKenney
2008-11-14 22:47 ` [patch 02/16] Marker fix unregister Mathieu Desnoyers
2008-11-14 22:47 ` [patch 03/16] markers: Add missing stdargs.h include, needed due to va_list usage Mathieu Desnoyers
2008-11-14 22:47 ` [patch 04/16] Markers use rcu_*_sched_notrace and notrace Mathieu Desnoyers
2008-11-14 22:47 ` [patch 05/16] Markers use module notifier Mathieu Desnoyers
2008-11-16  8:52   ` [PATCH] markers/tracpoints: fix non-modular build Ingo Molnar
2008-11-17  5:39     ` Mathieu Desnoyers
2008-11-14 22:47 ` [patch 06/16] Markers auto enable tracepoints (new API : trace_mark_tp()) Mathieu Desnoyers
2008-11-16  7:59   ` Ingo Molnar
2008-11-18  4:44     ` Mathieu Desnoyers
2008-11-18 16:30       ` Ingo Molnar
2008-11-23 16:40         ` Mathieu Desnoyers
2008-11-23 16:49           ` Ingo Molnar
2008-11-24  8:05             ` Mathieu Desnoyers
2008-11-25 12:23     ` KOSAKI Motohiro
2008-11-25 17:24       ` Frank Ch. Eigler
2008-11-14 22:47 ` [patch 07/16] Markers : create DEFINE_MARKER and GET_MARKER (new API) Mathieu Desnoyers
2008-11-14 22:47 ` [patch 08/16] Tracepoints : Samples fix teardown Mathieu Desnoyers
2008-11-14 22:47 ` Mathieu Desnoyers [this message]
2008-11-14 22:47 ` [patch 10/16] Tracepoints use rcu_*_sched_notrace Mathieu Desnoyers
2008-11-14 22:47 ` [patch 11/16] Tracepoint Use Unregister Return Value Mathieu Desnoyers
2008-11-14 22:47 ` [patch 12/16] Tracepoint do not put arguments in name Mathieu Desnoyers
2008-11-14 22:47 ` [patch 13/16] Tracepoints : use modules notifiers Mathieu Desnoyers
2008-11-14 22:47 ` [patch 14/16] Tracepoints : add DECLARE_TRACE() and DEFINE_TRACE() Mathieu Desnoyers
2008-11-14 22:47 ` [patch 15/16] Tracepoints : documentation fix teardown Mathieu Desnoyers
2008-11-14 22:47 ` [patch 16/16] marker_synchronize_unregister->tracepoint_synchronize_unregister Mathieu Desnoyers
2008-11-16  7:48   ` Ingo Molnar
2008-11-17  5:36     ` Mathieu Desnoyers

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