drm/nouveau: initialize chan->fence.lock before use
Fence lock needs to be initialized before any call to nouveau_channel_put
because it calls nouveau_channel_idle->nouveau_fence_update which uses
fence lock.
BUG: spinlock bad magic on CPU#0, test/24134
lock: ffff88019f90dba8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Pid: 24134, comm: test Not tainted 3.0.0-nv+ #800
Call Trace:
spin_bug+0x9c/0xa3
do_raw_spin_lock+0x29/0x13c
_raw_spin_lock+0x1e/0x22
nouveau_fence_update+0x2d/0xf1
nouveau_channel_idle+0x22/0xa0
nouveau_channel_put_unlocked+0x84/0x1bd
nouveau_channel_put+0x20/0x24
nouveau_channel_alloc+0x4ec/0x585
nouveau_ioctl_fifo_alloc+0x50/0x130
drm_ioctl+0x289/0x361
do_vfs_ioctl+0x4dd/0x52c
sys_ioctl+0x42/0x65
system_call_fastpath+0x16/0x1b
It's easily triggerable from userspace.
Additionally remove double initialization of chan->fence.pending.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
index a319d564..bb6ec9e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -158,6 +158,7 @@
INIT_LIST_HEAD(&chan->nvsw.vbl_wait);
INIT_LIST_HEAD(&chan->nvsw.flip);
INIT_LIST_HEAD(&chan->fence.pending);
+ spin_lock_init(&chan->fence.lock);
/* setup channel's memory and vm */
ret = nouveau_gpuobj_channel_init(chan, vram_handle, gart_handle);