[06/26] drm/nouveau: initialize chan->fence.lock before use

Greg KH
2011-11-19T00:09:10Z

From: Marcin Slusarz <marcin.slusarz@gmail.com>

commit 5e60ee780e792efe6dce97eceb110b1d30bab850 upstream.

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>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/gpu/drm/nouveau/nouveau_channel.c | 1 +
drivers/gpu/drm/nouveau/nouveau_fence.c | 2 --
2 files changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -159,6 +159,7 @@ nouveau_channel_alloc(struct drm_device
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);

/* Allocate DMA push buffer */
chan->pushbuf_bo = nouveau_channel_user_pushbuf_alloc(dev);
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -542,8 +542,6 @@ nouveau_fence_channel_init(struct nouvea
return ret;
}

- INIT_LIST_HEAD(&chan->fence.pending);
- spin_lock_init(&chan->fence.lock);
atomic_set(&chan->fence.last_sequence_irq, 0);
return 0;
}