From patchwork Sat Nov 2 17:35:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 11224187 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B2E014E5 for ; Sat, 2 Nov 2019 17:35:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1E2520862 for ; Sat, 2 Nov 2019 17:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726689AbfKBRf4 (ORCPT ); Sat, 2 Nov 2019 13:35:56 -0400 Received: from lb1-smtp-cloud9.xs4all.net ([194.109.24.22]:39249 "EHLO lb1-smtp-cloud9.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbfKBRf4 (ORCPT ); Sat, 2 Nov 2019 13:35:56 -0400 Received: from [192.168.2.10] ([46.9.232.237]) by smtp-cloud9.xs4all.net with ESMTPA id QxJNiRtRq9P9bQxJSiRqVx; Sat, 02 Nov 2019 18:35:50 +0100 From: Hans Verkuil Subject: [PATCH] vivid: media_device_cleanup was called too early To: Linux Media Mailing List Message-ID: Date: Sat, 2 Nov 2019 18:35:41 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 Content-Language: en-US X-CMAE-Envelope: MS4wfE9nyrXI5h/UTrxcaNCoR2GLGa14WNS5nZ1GtdeZI+MC4uChCadsPRRxERpvdrZ8AwoiaDMLNDRLYspgFZI0/pBXJjgTSALmZ1vetlHP2WjHKRe2h57f sBX2tT2EBTACDOs5pCvjX9/d9b65A8P5/2EMqZjSPoeMIGmqZJ8VDWXKwfnb3SUYzktT5j8dFZ+aow== Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Running the contrib/test/test-media script in v4l-utils with the vivid argument will cause this kernel warning: [ 104.748720] videodev: v4l2_release [ 104.748731] ------------[ cut here ]------------ [ 104.748750] DEBUG_LOCKS_WARN_ON(lock->magic != lock) [ 104.748790] WARNING: CPU: 6 PID: 1823 at kernel/locking/mutex.c:938 __mutex_lock+0x919/0xc10 [ 104.748800] Modules linked in: rc_cec vivid v4l2_tpg videobuf2_dma_contig cec rc_core v4l2_dv_timings videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc vmw_balloon vmw_vmci button vmwgfx [ 104.748845] CPU: 6 PID: 1823 Comm: sleep Not tainted 5.4.0-rc1-test-no #150 [ 104.748853] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019 [ 104.748867] RIP: 0010:__mutex_lock+0x919/0xc10 [ 104.748878] Code: 59 83 e8 9a fc 16 ff 44 8b 05 23 61 38 01 45 85 c0 0f 85 ef f7 ff ff 48 c7 c6 a0 1f 87 82 48 c7 c7 a0 1e 87 82 e8 cd bb f7 fe <0f> 0b e9 d5 f7 ff ff f6 c3 04 0f 84 3b fd ff ff 49 89 df 41 83 e7 [ 104.748886] RSP: 0018:ffff88811a357b80 EFLAGS: 00010286 [ 104.748895] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 104.748902] RDX: 0000000000000003 RSI: 0000000000000004 RDI: ffffed102346af62 [ 104.748910] RBP: ffff88811a357cf0 R08: ffffffff81217c91 R09: fffffbfff061c271 [ 104.748917] R10: fffffbfff061c270 R11: ffffffff830e1383 R12: ffff8881a46103c0 [ 104.748924] R13: 0000000000000000 R14: ffff8881a4614f90 R15: ffff8881a46153d0 [ 104.748933] FS: 0000000000000000(0000) GS:ffff8881b6780000(0000) knlGS:0000000000000000 [ 104.748940] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 104.748949] CR2: 00007f163fc9ca20 CR3: 0000000003013004 CR4: 00000000001606e0 [ 104.749036] Call Trace: [ 104.749051] ? _raw_spin_unlock+0x1f/0x30 [ 104.749067] ? llist_add_batch+0x33/0x50 [ 104.749081] ? tick_nohz_tick_stopped+0x19/0x30 [ 104.749130] ? v4l2_release.cold+0x6c/0xd6 [videodev] [ 104.749143] ? mutex_lock_io_nested+0xb80/0xb80 [ 104.749153] ? vprintk_emit+0xf2/0x220 [ 104.749191] ? vivid_req_validate+0x40/0x40 [vivid] [ 104.749201] ? printk+0xad/0xde [ 104.749211] ? kmsg_dump_rewind_nolock+0x54/0x54 [ 104.749226] ? locks_remove_file+0x78/0x2b0 [ 104.749248] ? __fsnotify_update_child_dentry_flags.part.0+0x170/0x170 [ 104.749281] ? vivid_req_validate+0x40/0x40 [vivid] [ 104.749321] ? v4l2_release.cold+0x6c/0xd6 [videodev] [ 104.749361] v4l2_release.cold+0x6c/0xd6 [videodev] [ 104.749378] __fput+0x15a/0x390 [ 104.749393] task_work_run+0xb2/0xe0 [ 104.749407] do_exit+0x4d0/0x1200 [ 104.749422] ? do_user_addr_fault+0x367/0x610 [ 104.749431] ? release_task+0x990/0x990 [ 104.749449] ? rwsem_spin_on_owner+0x170/0x170 [ 104.749463] ? vmacache_find+0xb2/0x100 [ 104.749476] do_group_exit+0x85/0x130 [ 104.749487] __x64_sys_exit_group+0x23/0x30 [ 104.749500] do_syscall_64+0x5e/0x1c0 [ 104.749511] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 104.749520] RIP: 0033:0x7f163fc5c9d6 [ 104.749536] Code: Bad RIP value. [ 104.749543] RSP: 002b:00007ffe6f3bec58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 104.749553] RAX: ffffffffffffffda RBX: 00007f163fd4d760 RCX: 00007f163fc5c9d6 [ 104.749560] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 104.749567] RBP: 0000000000000000 R08: 00000000000000e7 R09: ffffffffffffff80 [ 104.749574] R10: 00007ffe6f3beb24 R11: 0000000000000246 R12: 00007f163fd4d760 [ 104.749581] R13: 0000000000000002 R14: 00007f163fd56428 R15: 0000000000000000 [ 104.749597] ---[ end trace 66f20f73fc0daf79 ]--- This is caused by media_device_cleanup() which destroys v4l2_dev->mdev->req_queue_mutex. But v4l2_release() tries to lock that mutex after media_device_cleanup() is called. By moving media_device_cleanup() to the v4l2_device's release function it is guaranteed that the mutex is valid whenever v4l2_release is called. Signed-off-by: Hans Verkuil diff --git a/drivers/media/platform/vivid/vivid-core.c b/drivers/media/platform/vivid/vivid-core.c index dadfc59c92c5..b204c636dba6 100644 --- a/drivers/media/platform/vivid/vivid-core.c +++ b/drivers/media/platform/vivid/vivid-core.c @@ -648,6 +648,9 @@ static void vivid_dev_release(struct v4l2_device *v4l2_dev) vivid_free_controls(dev); v4l2_device_unregister(&dev->v4l2_dev); +#ifdef CONFIG_MEDIA_CONTROLLER + media_device_cleanup(&dev->mdev); +#endif vfree(dev->scaled_line); vfree(dev->blended_line); vfree(dev->edid); @@ -1755,7 +1758,6 @@ static int vivid_remove(struct platform_device *pdev) #ifdef CONFIG_MEDIA_CONTROLLER media_device_unregister(&dev->mdev); - media_device_cleanup(&dev->mdev); #endif if (dev->has_vid_cap) {