From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752134AbYI3FvX (ORCPT ); Tue, 30 Sep 2008 01:51:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751298AbYI3FvP (ORCPT ); Tue, 30 Sep 2008 01:51:15 -0400 Received: from tomts16.bellnexxia.net ([209.226.175.4]:58546 "EHLO tomts16-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188AbYI3FvO (ORCPT ); Tue, 30 Sep 2008 01:51:14 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArgEAENZ4UhMQWq+/2dsb2JhbACBZLoHgWc Date: Tue, 30 Sep 2008 01:51:12 -0400 From: Mathieu Desnoyers To: Ingo Molnar , "Frank Ch. Eigler" , Lai Jiangshan Cc: linux-kernel@vger.kernel.org Subject: [PATCH] Tracepoints fix reentrancy Message-ID: <20080930055112.GC16961@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 01:49:41 up 117 days, 10:30, 8 users, load average: 0.24, 0.26, 0.33 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The tracepoints had the same problem markers did have wrt reentrancy. Apply a similar fix using a rcu_barrier after each tracepoint mutex lock. Signed-off-by: Mathieu Desnoyers CC: Ingo Molnar CC: "Frank Ch. Eigler" CC: Lai Jiangshan --- kernel/tracepoint.c | 4 ++++ 1 file changed, 4 insertions(+) Index: linux-2.6-lttng/kernel/tracepoint.c =================================================================== --- linux-2.6-lttng.orig/kernel/tracepoint.c 2008-09-30 01:38:39.000000000 -0400 +++ linux-2.6-lttng/kernel/tracepoint.c 2008-09-30 01:39:56.000000000 -0400 @@ -361,6 +361,8 @@ int tracepoint_probe_register(const char mutex_lock(&tracepoints_mutex); entry = get_tracepoint(name); WARN_ON(!entry); + if (entry->rcu_pending) + rcu_barrier_sched(); tracepoint_entry_free_old(entry, old); end: mutex_unlock(&tracepoints_mutex); @@ -397,6 +399,8 @@ int tracepoint_probe_unregister(const ch entry = get_tracepoint(name); if (!entry) goto end; + if (entry->rcu_pending) + rcu_barrier_sched(); tracepoint_entry_free_old(entry, old); remove_tracepoint(name); /* Ignore busy error message */ ret = 0; -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68