Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752586AbcLCOsQ (ORCPT ); Sat, 3 Dec 2016 09:48:16 -0500 Received: from mail-wj0-f193.google.com ([209.85.210.193]:33206 "EHLO mail-wj0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751241AbcLCOsO (ORCPT ); Sat, 3 Dec 2016 09:48:14 -0500 From: Nicolai Stange To: Alex Deucher , =?UTF-8?q?Christian=20K=C3=B6nig?= Cc: David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Nicolai Stange Subject: [PATCH] drm/radeon: don't add files at control minor debugfs directory Date: Sat, 3 Dec 2016 15:47:00 +0100 Message-Id: <20161203144700.2307-1-nicstange@gmail.com> X-Mailer: git-send-email 2.10.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2231 Lines: 63 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 --- 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