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authorThomas Hellstrom <thellstrom@vmware.com>2009-03-02 11:10:56 +0100
committerDave Airlie <airlied@linux.ie>2009-03-03 09:50:20 +1000
commitfda714c29cdf360464059044b221450decb4b913 (patch)
treedc985f3c861d9490a1b5ffe82583497b6fe64236
parent171901d15deeef61aa8e1b0d0772404f39691b73 (diff)
downloadblackbird-obmc-linux-fda714c29cdf360464059044b221450decb4b913.tar.gz
blackbird-obmc-linux-fda714c29cdf360464059044b221450decb4b913.zip
drm: Avoid client deadlocks when the master disappears.
This is done by 1) Wake up lock waiters when we close the master file descriptor. Not when the master structure is removed, since the latter requires the waiters themselves to release the refcount on the master structure -> Deadlock. 2) Send a SIGTERM to all clients waiting for the lock. Normally these clients will get a SIGPIPE when the X server dies, but clients may also spin trying to grab the DRM lock, without getting any sort of notification. Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Dave Airlie <airlied@linux.ie>
-rw-r--r--drivers/gpu/drm/drm_fops.c14
-rw-r--r--drivers/gpu/drm/drm_lock.c1
-rw-r--r--drivers/gpu/drm/drm_stub.c8
3 files changed, 15 insertions, 8 deletions
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 6c020fe5431c..f52663ebe016 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -484,6 +484,7 @@ int drm_release(struct inode *inode, struct file *filp)
mutex_lock(&dev->struct_mutex);
if (file_priv->is_master) {
+ struct drm_master *master = file_priv->master;
struct drm_file *temp;
list_for_each_entry(temp, &dev->filelist, lhead) {
if ((temp->master == file_priv->master) &&
@@ -491,6 +492,19 @@ int drm_release(struct inode *inode, struct file *filp)
temp->authenticated = 0;
}
+ /**
+ * Since the master is disappearing, so is the
+ * possibility to lock.
+ */
+
+ if (master->lock.hw_lock) {
+ if (dev->sigdata.lock == master->lock.hw_lock)
+ dev->sigdata.lock = NULL;
+ master->lock.hw_lock = NULL;
+ master->lock.file_priv = NULL;
+ wake_up_interruptible_all(&master->lock.lock_queue);
+ }
+
if (file_priv->minor->master == file_priv->master) {
/* drop the reference held my the minor */
drm_master_put(&file_priv->minor->master);
diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index b03586fdabbd..e2f70a516c34 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -80,6 +80,7 @@ int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv)
__set_current_state(TASK_INTERRUPTIBLE);
if (!master->lock.hw_lock) {
/* Device has been unregistered */
+ send_sig(SIGTERM, current, 0);
ret = -EINTR;
break;
}
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index 7b251dd70811..096e2a37446d 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -146,14 +146,6 @@ static void drm_master_destroy(struct kref *kref)
drm_ht_remove(&master->magiclist);
- if (master->lock.hw_lock) {
- if (dev->sigdata.lock == master->lock.hw_lock)
- dev->sigdata.lock = NULL;
- master->lock.hw_lock = NULL;
- master->lock.file_priv = NULL;
- wake_up_interruptible_all(&master->lock.lock_queue);
- }
-
drm_free(master, sizeof(*master), DRM_MEM_DRIVER);
}
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