From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164Ab2LFVmA (ORCPT ); Thu, 6 Dec 2012 16:42:00 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:2827 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965247Ab2LFVl5 (ORCPT ); Thu, 6 Dec 2012 16:41:57 -0500 X-Authority-Analysis: v=2.0 cv=f9bK9ZOM c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Tlwa9QaMYFAA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=meVymXHHAAAA:8 a=gHdz8N29LIkA:10 a=VwQbUJbxAAAA:8 a=A1MkK4SXD2WQ7tJ_US8A:9 a=PUjeQqilurYA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1354830115.17101.28.camel@gandalf.local.home> Subject: Re: [v3.0 stable version][PATCH 1/2] ring-buffer: Fix NULL pointer if rb_set_head_page() fails From: Steven Rostedt To: Greg KH Cc: linux-kernel@vger.kernel.org, stable , Ingo Molnar , Andrew Morton , Thomas Gleixner , Frederic Weisbecker Date: Thu, 06 Dec 2012 16:41:55 -0500 In-Reply-To: <20121206201326.GA10874@kroah.com> References: <20121130161238.909829067@goodmis.org> <20121130161333.983378567@goodmis.org> <1354292203.6276.159.camel@gandalf.local.home> <20121206201326.GA10874@kroah.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-12-06 at 12:13 -0800, Greg KH wrote: > On Fri, Nov 30, 2012 at 11:16:43AM -0500, Steven Rostedt wrote: > > The function rb_set_head_page() searches the list of ring buffer > > pages for a the page that has the HEAD page flag set. If it does > > not find it, it will do a WARN_ON(), disable the ring buffer and > > return NULL, as this should never happen. > > > > But if this bug happens to happen, not all callers of this function > > can handle a NULL pointer being returned from it. That needs to be > > fixed. > > > > Cc: stable@vger.kernel.org # 3.0+ > > Signed-off-by: Steven Rostedt > > --- > > kernel/trace/ring_buffer.c | 9 +++++++-- > > 1 files changed, 7 insertions(+), 2 deletions(-) > > I don't understand why you sent these to stable@ right now, I don't see > them in Linus's tree, so why are they needed here? Answer below. > > Care to resend them when they hit Linus's tree? I'll try to remember, but I will most likely forget :-) I wrote the patches for each stable version while they were still fresh in my mind. I posted them so they would be there when they get into mainline and be easier to port for stable. By the time they are in mainline, they will be completely out of my mind :-) Also, it seems that Ingo has been so busy with NUMA, that my patches have been forgotten about. I may have to push to Linus directly :-/ -- Steve