From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758396AbZCRQ43 (ORCPT ); Wed, 18 Mar 2009 12:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753889AbZCRQ4U (ORCPT ); Wed, 18 Mar 2009 12:56:20 -0400 Received: from mail-ew0-f165.google.com ([209.85.219.165]:51191 "EHLO mail-ew0-f165.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753358AbZCRQ4T (ORCPT ); Wed, 18 Mar 2009 12:56:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=oyJHhU0YqgeIl7b2zzivCssjjKqaNFy36U4l/CK16CjlHsTRei2HzoTSW4jgWLmaNw zYQsbLsM7/MhON77rH/8U5Zewsm7g+8iR7d6UO6AahMysPDi+PPqx0jGpP0E0ylnpvkg HyBbMhrQd7YBEKx6vK6ayADOla4Gwf/IIvqrs= Date: Wed, 18 Mar 2009 17:56:12 +0100 From: Frederic Weisbecker To: Jaswinder Singh Rajput Cc: Ingo Molnar , Steven Rostedt , Peter Zijlstra , x86 maintainers , LKML Subject: Re: oops in tracepoint_update_probe_range() (was: Re: [oops -tip] : x86 AMD 64) Message-ID: <20090318165611.GC5981@nowhere> References: <1237393396.3322.6.camel@localhost.localdomain> <20090318163531.GE21331@elte.hu> <1237394936.3132.1.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1237394936.3132.1.camel@localhost.localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 18, 2009 at 10:18:56PM +0530, Jaswinder Singh Rajput wrote: > On Wed, 2009-03-18 at 17:35 +0100, Ingo Molnar wrote: > > * Jaswinder Singh Rajput wrote: > > > > > Good: f4c3c4cdb1de232 > > > Bad : 1e08816af0bc345 > > > > > > Config: > > > http://userweb.kernel.org/~jaswinder/oops_20090318/config-hpdv5-tip-bad-20090318 > > > > > > oops: > > > http://userweb.kernel.org/~jaswinder/oops_20090318/oops_page1.jpg > > > http://userweb.kernel.org/~jaswinder/oops_20090318/oops_page2.jpg > > > http://userweb.kernel.org/~jaswinder/oops_20090318/oops_page3.jpg > > > http://userweb.kernel.org/~jaswinder/oops_20090318/oops_page4.jpg > > > > > > > > > > Steve, Frederic - the crashes above are in: > > > > tracepoint_update_probe_range() > > > > in a modular kernel apparently. > > > > This fixed the oops for me, Is this looks OK to you: > > Subject: [PATCH] x86: tracepoint.c fix oops > > 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 > > Signed-off-by: Jaswinder Singh Rajput > --- > kernel/tracepoint.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c > index 7960274..80d1353 100644 > --- a/kernel/tracepoint.c > +++ b/kernel/tracepoint.c > @@ -280,6 +280,8 @@ void tracepoint_update_probe_range(struct tracepoint *begin, > > mutex_lock(&tracepoints_mutex); > for (iter = begin; iter < end; iter++) { > + if (!iter) > + goto out; > mark_entry = get_tracepoint(iter->name); > if (mark_entry) { > set_tracepoint(&mark_entry, iter, > @@ -288,6 +290,7 @@ void tracepoint_update_probe_range(struct tracepoint *begin, > disable_tracepoint(iter); > } > } > +out: > mutex_unlock(&tracepoints_mutex); > } Ok, it should fix the crash. But I think the real problem remains: iter is not supposed to point to NULL, this is a section range: tracepoint_update_probe_range(__start___tracepoints, __stop___tracepoints); It seems to mean that the section is empty. > -- > 1.6.0.6 > > >