From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934886Ab3DKUfP (ORCPT ); Thu, 11 Apr 2013 16:35:15 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:5168 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756748Ab3DKU0L (ORCPT ); Thu, 11 Apr 2013 16:26:11 -0400 X-Authority-Analysis: v=2.0 cv=F+XVh9dN c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=dW28dkJG3RcA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=cAuAz9kGQ5cA:10 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=jmWCE8W1go-RpaolMxwA:9 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130411202552.061647157@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 11 Apr 2013 16:25:39 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paul McKenney Subject: [ 036/171 ] tracing: Fix free of probe entry by calling call_rcu_sched() References: <20130411202503.783159048@goodmis.org> Content-Disposition: inline; filename=0036-tracing-Fix-free-of-probe-entry-by-calling-call_rcu_.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.2 stable review patch. If anyone has any objections, please let me know. ------------------ From: "Steven Rostedt (Red Hat)" [ Upstream commit 740466bc89ad8bd5afcc8de220f715f62b21e365 ] Because function tracing is very invasive, and can even trace calls to rcu_read_lock(), RCU access in function tracing is done with preempt_disable_notrace(). This requires a synchronize_sched() for updates and not a synchronize_rcu(). Function probes (traceon, traceoff, etc) must be freed after a synchronize_sched() after its entry has been removed from the hash. But call_rcu() is used. Fix this by using call_rcu_sched(). Also fix the usage to use hlist_del_rcu() instead of hlist_del(). Cc: stable@vger.kernel.org Cc: Paul McKenney Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 781ecc2..c27095d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3002,8 +3002,8 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, continue; } - hlist_del(&entry->node); - call_rcu(&entry->rcu, ftrace_free_entry_rcu); + hlist_del_rcu(&entry->node); + call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu); } } __disable_ftrace_function_probe(); -- 1.7.10.4