Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751765AbcLEH1K (ORCPT ); Mon, 5 Dec 2016 02:27:10 -0500 Received: from mail-wj0-f196.google.com ([209.85.210.196]:35411 "EHLO mail-wj0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750785AbcLEH1E (ORCPT ); Mon, 5 Dec 2016 02:27:04 -0500 Date: Mon, 5 Dec 2016 08:27:09 +0100 From: Daniel Vetter To: Nicolai Stange Cc: Alex Deucher , Christian =?iso-8859-1?Q?K=F6nig?= , Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/radeon: don't add files at control minor debugfs directory Message-ID: <20161205072709.zcoja6eak2sjgd2k@phenom.ffwll.local> Mail-Followup-To: Nicolai Stange , Alex Deucher , Christian =?iso-8859-1?Q?K=F6nig?= , Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <20161203144700.2307-1-nicstange@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161203144700.2307-1-nicstange@gmail.com> X-Operating-System: Linux phenom 4.8.0-1-amd64 User-Agent: NeoMutt/20161104 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2743 Lines: 78 On Sat, Dec 03, 2016 at 03:47:00PM +0100, Nicolai Stange wrote: > Since commit 8a357d10043c ("drm: Nerf DRM_CONTROL nodes"), a > struct drm_device's ->control member is always NULL. > > In the case of CONFIG_DEBUG_FS=y, radeon_debugfs_add_files() accesses > ->control->debugfs_root though. This results in the following Oops: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 > IP: radeon_debugfs_add_files+0x90/0x100 [radeon] > PGD 0 > Oops: 0000 [#1] SMP > [...] > Call Trace: > ? work_on_cpu+0xb0/0xb0 > radeon_fence_driver_init+0x120/0x150 [radeon] > si_init+0x122/0xd50 [radeon] > ? _raw_spin_unlock_irq+0x2c/0x40 > ? device_pm_check_callbacks+0xb3/0xc0 > radeon_device_init+0x958/0xda0 [radeon] > radeon_driver_load_kms+0x9a/0x210 [radeon] > drm_dev_register+0xa9/0xd0 [drm] > drm_get_pci_dev+0x9c/0x1e0 [drm] > radeon_pci_probe+0xb8/0xe0 [radeon] > [...] > > Fix this by omitting the drm_debugfs_create_files() call for the > control minor debugfs directory which is now non-existent anyway. > > Fixes: 8a357d10043c ("drm: Nerf DRM_CONTROL nodes") > Signed-off-by: Nicolai Stange Applied to drm-misc with Dave's irc ack, thanks for your patch. -Daniel > --- > Tested on top of next-20161202. > That 8a357d10043c ("drm: Nerf DRM_CONTROL nodes") > is in next since 20161201. > > drivers/gpu/drm/radeon/radeon_device.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c > index 60a8920..8a1df2a 100644 > --- a/drivers/gpu/drm/radeon/radeon_device.c > +++ b/drivers/gpu/drm/radeon/radeon_device.c > @@ -1949,9 +1949,6 @@ int radeon_debugfs_add_files(struct radeon_device *rdev, > rdev->debugfs_count = i; > #if defined(CONFIG_DEBUG_FS) > drm_debugfs_create_files(files, nfiles, > - rdev->ddev->control->debugfs_root, > - rdev->ddev->control); > - drm_debugfs_create_files(files, nfiles, > rdev->ddev->primary->debugfs_root, > rdev->ddev->primary); > #endif > @@ -1966,9 +1963,6 @@ static void radeon_debugfs_remove_files(struct radeon_device *rdev) > for (i = 0; i < rdev->debugfs_count; i++) { > drm_debugfs_remove_files(rdev->debugfs[i].files, > rdev->debugfs[i].num_files, > - rdev->ddev->control); > - drm_debugfs_remove_files(rdev->debugfs[i].files, > - rdev->debugfs[i].num_files, > rdev->ddev->primary); > } > #endif > -- > 2.10.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch