From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757240AbZCRRxu (ORCPT ); Wed, 18 Mar 2009 13:53:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753449AbZCRRxm (ORCPT ); Wed, 18 Mar 2009 13:53:42 -0400 Received: from hera.kernel.org ([140.211.167.34]:53838 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752614AbZCRRxl (ORCPT ); Wed, 18 Mar 2009 13:53:41 -0400 Subject: Re: [tip:tracing/ftrace] tracing: fix oops in tracepoint_update_probe_range() From: Jaswinder Singh Rajput To: mingo@redhat.com Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, jaswinderrajput@gmail.com, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org In-Reply-To: <1237397901.22438.4.camel@ht.satnam> References: <1237394936.3132.1.camel@localhost.localdomain> <1237397901.22438.4.camel@ht.satnam> Content-Type: text/plain Date: Wed, 18 Mar 2009 23:22:58 +0530 Message-Id: <1237398778.22438.7.camel@ht.satnam> Mime-Version: 1.0 X-Mailer: Evolution 2.24.5 (2.24.5-1.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2009-03-18 at 23:08 +0530, Jaswinder Singh Rajput wrote: > On Wed, 2009-03-18 at 17:33 +0000, Jaswinder Singh Rajput wrote: > > Commit-ID: 7d1832698e6e422cc2cf0d80b9c50ca567e758a3 > > Gitweb: http://git.kernel.org/tip/7d1832698e6e422cc2cf0d80b9c50ca567e758a3 > > Author: Jaswinder Singh Rajput > > AuthorDate: Wed, 18 Mar 2009 22:18:56 +0530 > > Commit: Ingo Molnar > > CommitDate: Wed, 18 Mar 2009 18:30:43 +0100 > > > > tracing: fix oops in tracepoint_update_probe_range() > > > > Change this crash: > > > > BUG: unable to handle kernel NULL pointer dereference at (null) > > IP: [] tracepoint_update_probe_range+0x1f/0x9b > > PGD 13d5fb067 PUD 13d688067 PMD 0 > > Oops: 0000 [#1] SMP > > > > To a more debuggable WARN_ONCE(). > > > > Signed-off-by: Jaswinder Singh Rajput > > Cc: Frederic Weisbecker > > Cc: Steven Rostedt > > LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain> > > [ moved the check outside the lock and added a WARN_ON(). ] > > Signed-off-by: Ingo Molnar > > > > > > --- > > kernel/tracepoint.c | 9 +++++++-- > > 1 files changed, 7 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c > > index 7960274..8bc1a06 100644 > > --- a/kernel/tracepoint.c > > +++ b/kernel/tracepoint.c > > @@ -272,12 +272,17 @@ static void disable_tracepoint(struct tracepoint *elem) > > * > > * Updates the probe callback corresponding to a range of tracepoints. > > */ > > -void tracepoint_update_probe_range(struct tracepoint *begin, > > - struct tracepoint *end) > > +void > > +tracepoint_update_probe_range(struct tracepoint *begin, struct tracepoint *end) > > { > > struct tracepoint *iter; > > struct tracepoint_entry *mark_entry; > > > > + if (!iter) { > > + WARN_ON_ONCE(1); > > + goto out; > > + } > > + > > There is no out, it should be : > > + if (!iter) { > + WARN_ON_ONCE(1); > + return; > + } > + > hmm, who is setting iter :p -- JSR