https://github.com/torvalds/linux
Revision 39b4d07aa3583ceefe73622841303a0a3e942ca1 authored by Chris Wilson on 30 September 2010, 08:10:26 UTC, committed by Dave Airlie on 01 October 2010, 11:08:45 UTC
In order to be fully threadsafe we need to check that the drm_gem_object refcount is still 0 after acquiring the mutex in order to call the free function. Otherwise, we may encounter scenarios like: Thread A: Thread B: drm_gem_close unreference_unlocked kref_put mutex_lock ... i915_gem_evict ... kref_get -> BUG ... i915_gem_unbind ... kref_put ... i915_gem_object_free ... mutex_unlock mutex_lock i915_gem_object_free -> BUG i915_gem_object_unbind kfree mutex_unlock Note that no driver is currently using the free_unlocked vfunc and it is scheduled for removal, hasten that process. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30454 Reported-and-Tested-by: Magnus Kessler <Magnus.Kessler@gmx.net> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
1 parent 29d08b3
Tip revision: 39b4d07aa3583ceefe73622841303a0a3e942ca1 authored by Chris Wilson on 30 September 2010, 08:10:26 UTC
drm: Hold the mutex when dropping the last GEM reference (v2)
drm: Hold the mutex when dropping the last GEM reference (v2)
Tip revision: 39b4d07
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arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
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ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 936 bytes |
.mailmap | -rw-r--r-- | 3.9 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 91.8 KB |
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MAINTAINERS | -rw-r--r-- | 173.6 KB |
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README | -rw-r--r-- | 17.0 KB |
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