diff options
| author | Thomas Hellstrom <unichrome@shipmail.org> | 2005-04-20 18:50:49 +0000 |
|---|---|---|
| committer | Thomas Hellstrom <unichrome@shipmail.org> | 2005-04-20 18:50:49 +0000 |
| commit | 699d4ad53a62e46344b672365dda0be4001edd99 (patch) | |
| tree | 1ac0e9023041d9962ad16debe48afdc0f64935b3 /linux-core/drm_lock.c | |
| parent | 2b8dc25dc549533f1567093fb7dffc06d6f55268 (diff) | |
A fix for a locking bug which is triggered when a client tries to lock with
flag DMA_QUIESCENT (typically the X server), but gets interrupted by a
signal. The locking IOCTL should then return an error, but if
DMA_QUIESCENT succeeds it returns 0, and the client falsely thinks it
has the lock. In addition The client waits for DMA_QUISCENT and
possibly DMA_READY without having the lock.
Diffstat (limited to 'linux-core/drm_lock.c')
| -rw-r--r-- | linux-core/drm_lock.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/linux-core/drm_lock.c b/linux-core/drm_lock.c index b9833724..048f084f 100644 --- a/linux-core/drm_lock.c +++ b/linux-core/drm_lock.c @@ -99,6 +99,9 @@ int drm_lock(struct inode *inode, struct file *filp, current->state = TASK_RUNNING; remove_wait_queue(&dev->lock.lock_queue, &entry); + DRM_DEBUG( "%d %s\n", lock.context, ret ? "interrupted" : "has lock" ); + if (ret) return ret; + sigemptyset(&dev->sigmask); sigaddset(&dev->sigmask, SIGSTOP); sigaddset(&dev->sigmask, SIGTSTP); @@ -111,8 +114,12 @@ int drm_lock(struct inode *inode, struct file *filp, if (dev->driver->dma_ready && (lock.flags & _DRM_LOCK_READY)) dev->driver->dma_ready(dev); - if (dev->driver->dma_quiescent && (lock.flags & _DRM_LOCK_QUIESCENT)) - return dev->driver->dma_quiescent(dev); + if (dev->driver->dma_quiescent && (lock.flags & _DRM_LOCK_QUIESCENT)) { + if (dev->driver->dma_quiescent(dev)) { + DRM_DEBUG( "%d waiting for DMA quiescent\n", lock.context); + return DRM_ERR(EBUSY); + } + } if (dev->driver->kernel_context_switch && dev->last_context != lock.context) { @@ -120,9 +127,7 @@ int drm_lock(struct inode *inode, struct file *filp, lock.context); } - DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock"); - - return ret; + return 0; } /** |