https://bugzilla.kernel.org/show_bug.cgi?id=84041

Bug ID: 84041 Summary: I built my kernel with lockdep, and caught a possible deadlock while playing video using vdpau on radeon driver. Product: Drivers Version: 2.5 Kernel Version: Possible deadlock when using dri PRIME Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: yshuiv7@gmail.com Regression: No

dmesg:

[ 166.768423] ============================================= [ 166.768424] [ INFO: possible recursive locking detected ] [ 166.768429] 3.16.1 #7 Not tainted [ 166.768430] --------------------------------------------- [ 166.768432] Xorg.bin/319 is trying to acquire lock: [ 166.768435] (&dev->struct_mutex){+.+.+.}, at: [<ffffffff8146efb3>] i915_gem_unmap_dma_buf+0x33/0xd0 [ 166.768461] but task is already holding lock: [ 166.768462] (&dev->struct_mutex){+.+.+.}, at: [<ffffffff8143b382>] drm_gem_object_handle_unreference_unlocked+0x102/0x130 [ 166.768475] other info that might help us debug this: [ 166.768477] Possible unsafe locking scenario:

[ 166.768479] CPU0 [ 166.768480] ---- [ 166.768481] lock(&dev->struct_mutex); [ 166.768483] lock(&dev->struct_mutex); [ 166.768484] *** DEADLOCK ***

[ 166.768486] May be due to missing lock nesting notation

[ 166.768488] 1 lock held by Xorg.bin/319: [ 166.768489] #0: (&dev->struct_mutex){+.+.+.}, at: [<ffffffff8143b382>] drm_gem_object_handle_unreference_unlocked+0x102/0x130 [ 166.768493] stack backtrace: [ 166.768496] CPU: 0 PID: 319 Comm: Xorg.bin Not tainted 3.16.1-zen-v7+ #7 [ 166.768499] Hardware name: LENOVO 20347/Lenovo Y40-70, BIOS 99CN24WW(V1.07) 07/28/2014 [ 166.768500] ffffffff825f02c0 ffff880098dcfae0 ffffffff8174e942 ffff88024f065fa0 [ 166.768504] ffff880098dcfbb0 ffffffff810ca996 ffff8802553b8e88 00000000fffff200 [ 166.768506] ffff880098dcfb20 ffffffff810c8abd ffff8802553b8ea8 ffff88024f066878 [ 166.768510] Call Trace: [ 166.768520] [<ffffffff8174e942>] dump_stack+0x4d/0x6f [ 166.768528] [<ffffffff810ca996>] __lock_acquire+0x1b06/0x1fa0 [ 166.768531] [<ffffffff810c8abd>] ? trace_hardirqs_on_caller+0x15d/0x200 [ 166.768534] [<ffffffff810cb6a5>] lock_acquire+0x95/0x130 [ 166.768537] [<ffffffff8146efb3>] ? i915_gem_unmap_dma_buf+0x33/0xd0 [ 166.768542] [<ffffffff817538b3>] mutex_lock_nested+0x63/0x410 [ 166.768544] [<ffffffff8146efb3>] ? i915_gem_unmap_dma_buf+0x33/0xd0 [ 166.768546] [<ffffffff810c8935>] ? mark_held_locks+0x75/0xa0 [ 166.768549] [<ffffffff8146efb3>] i915_gem_unmap_dma_buf+0x33/0xd0 [ 166.768556] [<ffffffff814fc88c>] dma_buf_unmap_attachment+0x4c/0x70 [ 166.768564] [<ffffffff81451d82>] drm_prime_gem_destroy+0x22/0x40 [ 166.768662] [<ffffffffa02ed663>] radeon_gem_object_free+0x33/0x40 [radeon] [ 166.768665] [<ffffffff8143b267>] drm_gem_object_free+0x27/0x40 [ 166.768667] [<ffffffff8143b3a0>] drm_gem_object_handle_unreference_unlocked+0x120/0x130 [ 166.768671] [<ffffffff8143b52a>] drm_gem_handle_delete+0xba/0x110 [ 166.768674] [<ffffffff8143b8e5>] drm_gem_close_ioctl+0x25/0x30 [ 166.768676] [<ffffffff814394d7>] drm_ioctl+0x197/0x680 [ 166.768680] [<ffffffff81757525>] ? _raw_spin_unlock_irqrestore+0x55/0x70 [ 166.768682] [<ffffffff810c8abd>] ? trace_hardirqs_on_caller+0x15d/0x200 [ 166.768684] [<ffffffff810c8b6d>] ? trace_hardirqs_on+0xd/0x10 [ 166.768703] [<ffffffffa02bd04c>] radeon_drm_ioctl+0x4c/0x80 [radeon] [ 166.768708] [<ffffffff811d5a00>] do_vfs_ioctl+0x2f0/0x4f0 [ 166.768710] [<ffffffff811e0b3c>] ? __fget+0xac/0xf0 [ 166.768712] [<ffffffff811e0a95>] ? __fget+0x5/0xf0 [ 166.768714] [<ffffffff811d5c41>] SyS_ioctl+0x41/0x80 [ 166.768717] [<ffffffff8175832a>] tracesys+0xd4/0xd9