From 8a07fed44b126f48020f122b9e6bf05d8c48f281 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 23 Aug 2016 10:25:58 +0100 Subject: [PATCH] drm/i915/dvo: Remove dangling call to drm_encoder_cleanup() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If we hit the error path, we have never called drm_encoder_init() and so have nothing to cleanup. Doing so hits a null dereference: [ 10.066261] BUG: unable to handle kernel NULL pointer dereference at 00000104 [ 10.066273] IP: [] mutex_lock+0xa/0x15 [ 10.066287] *pde = 00000000 [ 10.066295] Oops: 0002 [#1] [ 10.066302] Modules linked in: i915(+) video i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm iTCO_wdt iTCO_vendor_support ppdev evdev snd_intel8x0 snd_ac97_codec ac97_bus psmouse snd_pcm snd_timer snd pcspkr uhci_hcd ehci_pci soundcore sr_mod ehci_hcd serio_raw i2c_i801 usbcore i2c_smbus cdrom lpc_ich mfd_core rng_core e100 mii floppy parport_pc parport acpi_cpufreq button processor usb_common eeprom lm85 hwmon_vid autofs4 [ 10.066378] CPU: 0 PID: 132 Comm: systemd-udevd Not tainted 4.8.0-rc3-00013-gef0e1ea #34 [ 10.066389] Hardware name: MicroLink /D865GLC , BIOS BF86510A.86A.0077.P25.0508040031 08/04/2005 [ 10.066401] task: f62db800 task.stack: f5970000 [ 10.066409] EIP: 0060:[] EFLAGS: 00010286 CPU: 0 [ 10.066417] EIP is at mutex_lock+0xa/0x15 [ 10.066424] EAX: 00000104 EBX: 00000104 ECX: 00000000 EDX: 80000000 [ 10.066432] ESI: 00000000 EDI: 00000104 EBP: f5be8000 ESP: f5971b58 [ 10.066439] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 [ 10.066446] CR0: 80050033 CR2: 00000104 CR3: 35945000 CR4: 000006d0 [ 10.066453] Stack: [ 10.066459] f503d740 f824dddf 00000000 f61170c0 f61170c0 f82371ae f850f40e 00000001 [ 10.066476] f61170c0 f5971bcc f5be8000 f9c2d401 00000001 f8236fcc 00000001 00000000 [ 10.066491] f5144014 f5be8104 00000008 f9c5267c 00000007 f61170c0 f5144400 f9c4ff00 [ 10.066507] Call Trace: [ 10.066526] [] ? drm_modeset_lock_all+0x27/0xb3 [drm] [ 10.066545] [] ? drm_encoder_cleanup+0x1a/0x132 [drm] [ 10.066559] [] ? drm_atomic_helper_connector_reset+0x3f/0x5c [drm_kms_helper] [ 10.066644] [] ? intel_dvo_init+0x569/0x788 [i915] [ 10.066663] [] ? drm_encoder_init+0x43/0x20b [drm] [ 10.066734] [] ? intel_modeset_init+0x1436/0x17dd [i915] [ 10.066791] [] ? i915_driver_load+0x85a/0x15d3 [i915] [ 10.066846] [] ? i915_driver_open+0x5/0x5 [i915] [ 10.066857] [] ? firmware_map_add_entry.part.2+0xc/0xc [ 10.066868] [] ? pci_device_probe+0x8e/0x11c [ 10.066878] [] ? driver_probe_device+0x1db/0x62e [ 10.066888] [] ? kernfs_new_node+0x29/0x9c [ 10.066897] [] ? pci_match_device+0xd9/0x161 [ 10.066905] [] ? kernfs_create_dir_ns+0x42/0x88 [ 10.066914] [] ? __driver_attach+0xe6/0x11b [ 10.066924] [] ? kobject_add_internal+0x1bb/0x44f [ 10.066933] [] ? driver_probe_device+0x62e/0x62e [ 10.066941] [] ? bus_for_each_dev+0x46/0x7f [ 10.066950] [] ? driver_attach+0x1a/0x34 [ 10.066958] [] ? driver_probe_device+0x62e/0x62e [ 10.066966] [] ? bus_add_driver+0x217/0x32a [ 10.066975] [] ? 0xf8403000 [ 10.066982] [] ? driver_register+0x5f/0x108 [ 10.066991] [] ? do_one_initcall+0x49/0x1f6 [ 10.067000] [] ? pick_next_task_fair+0x14b/0x2a3 [ 10.067008] [] ? __schedule+0x15c/0x4fe [ 10.067016] [] ? preempt_schedule_common+0x19/0x3c [ 10.067027] [] ? do_init_module+0x17/0x230 [ 10.067035] [] ? _cond_resched+0x12/0x1a [ 10.067044] [] ? kmem_cache_alloc+0x8f/0x11f [ 10.067052] [] ? do_init_module+0x17/0x230 [ 10.067060] [] ? kfree+0x137/0x203 [ 10.067068] [] ? do_init_module+0x76/0x230 [ 10.067078] [] ? load_module+0x2a39/0x333f [ 10.067087] [] ? SyS_finit_module+0x96/0xd5 [ 10.067096] [] ? vm_mmap_pgoff+0x79/0xa0 [ 10.067105] [] ? do_fast_syscall_32+0xb5/0x1b0 [ 10.067114] [] ? sysenter_past_esp+0x47/0x75 [ 10.067121] Code: c8 f7 76 c1 e8 8e cc d2 ff e9 45 fe ff ff 66 90 66 90 66 90 66 90 90 ff 00 7f 05 e8 4e 0c 00 00 c3 53 89 c3 e8 75 ec ff ff 89 d8 08 79 05 e8 fa 0a 00 00 5b c3 53 89 c3 85 c0 74 1b 8b 03 83 [ 10.067180] EIP: [] mutex_lock+0xa/0x15 SS:ESP 0068:f5971b58 [ 10.067190] CR2: 0000000000000104 [ 10.067222] ---[ end trace 049f1f09da45a856 ]--- Reported-by: Meelis Roos Fixes: 580d8ed522e0 ("drm/i915: Give encoders useful names") Reviewed-by: David Weinehall Signed-off-by: Chris Wilson Cc: Ville Syrjälä Cc: drm-intel-fixes@lists.freedesktop.org Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/20160823092558.14931-1-chris@chris-wilson.co.uk (cherry picked from commit 8f76aa0ebe0b7787afe768d9df80031e832d2520) --- drivers/gpu/drm/i915/intel_dvo.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c index 47bdf9dad0d3..b9e5a63a7c9e 100644 --- a/drivers/gpu/drm/i915/intel_dvo.c +++ b/drivers/gpu/drm/i915/intel_dvo.c @@ -554,7 +554,6 @@ void intel_dvo_init(struct drm_device *dev) return; } - drm_encoder_cleanup(&intel_encoder->base); kfree(intel_dvo); kfree(intel_connector); } -- 2.20.1