Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753497AbcCJQOX (ORCPT ); Thu, 10 Mar 2016 11:14:23 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:50270 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753090AbcCJQOO convert rfc822-to-8bit (ORCPT ); Thu, 10 Mar 2016 11:14:14 -0500 Message-ID: <1457626448.25459.17.camel@canonical.com> Subject: Re: [PATCH 3.13.y-ckt 078/138] drm/radeon: hold reference to fences in radeon_sa_bo_new From: Kamal Mostafa To: Nicolai =?ISO-8859-1?Q?H=E4hnle?= , linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Date: Thu, 10 Mar 2016 08:14:08 -0800 In-Reply-To: <56E0B4E4.90704@amd.com> References: <1457565265-15195-1-git-send-email-kamal@canonical.com> <1457565265-15195-79-git-send-email-kamal@canonical.com> <56E0B4E4.90704@amd.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5-1ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2029 Lines: 62 On Wed, 2016-03-09 at 18:42 -0500, Nicolai Hähnle wrote: > On 09.03.2016 18:13, Kamal Mostafa wrote: > > > > 3.13.11-ckt36 -stable review patch.  If anyone has any objections, > > please let me know. > Please drop the patch for now, it causes a NULL pointer dereference > on  > kernels <= 3.17. We will follow up with a correctly backported patch. > > Thanks, > Nicolai Dropped from 3.13-stable.  Thanks for the heads-up, Nicolai!  -Kamal > > > > > > ---8<------------------------------------------------------------ > > > > From: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= > > > > commit f6ff4f67cdf8455d0a4226eeeaf5af17c37d05eb upstream. > > > > An arbitrary amount of time can pass between spin_unlock and > > radeon_fence_wait_any, so we need to ensure that nobody frees the > > fences from under us. > > > > Based on the analogous fix for amdgpu. > > > > Signed-off-by: Nicolai Hähnle > > Reviewed-by: Christian König > > Signed-off-by: Kamal Mostafa > > --- > >   drivers/gpu/drm/radeon/radeon_sa.c | 5 +++++ > >   1 file changed, 5 insertions(+) > > > > diff --git a/drivers/gpu/drm/radeon/radeon_sa.c > > b/drivers/gpu/drm/radeon/radeon_sa.c > > index f0bac68..bb16684 100644 > > --- a/drivers/gpu/drm/radeon/radeon_sa.c > > +++ b/drivers/gpu/drm/radeon/radeon_sa.c > > @@ -349,8 +349,13 @@ int radeon_sa_bo_new(struct radeon_device > > *rdev, > >    /* see if we can skip over some > > allocations */ > >    } while (radeon_sa_bo_next_hole(sa_manager, > > fences, tries)); > > > > + for (i = 0; i < RADEON_NUM_RINGS; ++i) > > + radeon_fence_ref(fences[i]); > > + > >    spin_unlock(&sa_manager->wq.lock); > >    r = radeon_fence_wait_any(rdev, fences, false); > > + for (i = 0; i < RADEON_NUM_RINGS; ++i) > > + radeon_fence_unref(&fences[i]); > >    spin_lock(&sa_manager->wq.lock); > >    /* if we have nothing to wait for block */ > >    if (r == -ENOENT && block) { > >