From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422904Ab2LGAgr (ORCPT ); Thu, 6 Dec 2012 19:36:47 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:58648 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422886Ab2LGAgp (ORCPT ); Thu, 6 Dec 2012 19:36:45 -0500 X-Sasl-enc: CIbydZX1n4v+kHdMC5XJivkkCOJQ/SDiYLstmlWfEKe+ 1354840604 Date: Thu, 6 Dec 2012 16:36:43 -0800 From: Greg KH To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, stable , Ingo Molnar , Andrew Morton , Thomas Gleixner , Frederic Weisbecker Subject: Re: [v3.0 stable version][PATCH 1/2] ring-buffer: Fix NULL pointer if rb_set_head_page() fails Message-ID: <20121207003643.GA30526@kroah.com> References: <20121130161238.909829067@goodmis.org> <20121130161333.983378567@goodmis.org> <1354292203.6276.159.camel@gandalf.local.home> <20121206201326.GA10874@kroah.com> <1354830115.17101.28.camel@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1354830115.17101.28.camel@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 06, 2012 at 04:41:55PM -0500, Steven Rostedt wrote: > 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 :-) Ok, if they are that important, consider them forgotten from my mind as well :) greg k-h