From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756968AbaCRTuZ (ORCPT ); Tue, 18 Mar 2014 15:50:25 -0400 Received: from mail-ee0-f51.google.com ([74.125.83.51]:64651 "EHLO mail-ee0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755509AbaCRTuW (ORCPT ); Tue, 18 Mar 2014 15:50:22 -0400 Date: Tue, 18 Mar 2014 20:50:07 +0100 From: Daniel Vetter To: Steven Rostedt Cc: LKML , Daniel Vetter , Ben Widawsky , Chris Wilson , Ramkumar Ramachandra , Jiri Olsa , Arnaldo Carvalho de Melo , Namhyung Kim , stable Subject: Re: [PATCH] drm/i915: Do not dereference pointers from ring buffer in evict event Message-ID: <20140318195007.GJ30571@phenom.ffwll.local> Mail-Followup-To: Steven Rostedt , LKML , Ben Widawsky , Chris Wilson , Ramkumar Ramachandra , Jiri Olsa , Arnaldo Carvalho de Melo , Namhyung Kim , stable References: <20140318112737.2192898a@gandalf.local.home> <20140318113136.02d2e08b@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140318113136.02d2e08b@gandalf.local.home> X-Operating-System: Linux phenom 3.12.0+ 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 Tue, Mar 18, 2014 at 11:31:36AM -0400, Steven Rostedt wrote: > On Tue, 18 Mar 2014 11:27:37 -0400 > Steven Rostedt wrote: > > > The TP_printk() should never dereference any pointers, because the ring > > buffer can be read at some unknown time in the future. If a device no > > longer exists, it can cause a kernel oops. This also makes this > > event useless when saving the ring buffer in userspaces tools such as > > perf and trace-cmd. > > > > The i915_gem_evict_vm dereferences the vm pointer which may also not > > exist when the ring buffer is read sometime in the future. > > > > Link: http://lkml.kernel.org/r/1395095198-20034-3-git-send-email-artagnon@gmail.com > > Reported-by: Ramkumar Ramachandra Cc: > > stable@vger.kernel.org # 3.13+ > > Bah, claw's mail is playing havoc with my line wraps. Please fix the > above when applying, or I can send anothe patch. Thanks :-) > > I had to re-insert the patch due to it but didn't see the screw up with > the Cc of stable. Patch applied and cc: stable fixed, thanks. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch