tree d5565422ba396f70805a189a082ca5ee29cb8a53
parent e995ca0b8139c5f6807095464e969931b443f55a
author Leo (Sunpeng) Li <sunpeng.li@amd.com> 1516189868 +0100
committer Maarten Lankhorst <maarten.lankhorst@linux.intel.com> 1517308046 +0100

drm/atomic: Fix memleak on ERESTARTSYS during non-blocking commits

During a non-blocking commit, it is possible to return before the
commit_tail work is queued (-ERESTARTSYS, for example).

Since a reference on the crtc commit object is obtained for the pending
vblank event when preparing the commit, the above situation will leave
us with an extra reference.

Therefore, if the commit_tail worker has not consumed the event at the
end of a commit, release it's reference.

Changes since v1:
- Also check for state->event->base.completion being set, to
  handle the case where stall_checks() fails in setup_crtc_commit().
Changes since v2:
- Add a flag to drm_crtc_commit, to prevent dereferencing a freed event.
  i915 may unreference the state in a worker.

Fixes: 24835e442f28 ("drm: reference count event->completion")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com> #v1
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180117115108.29608-1-maarten.lankhorst@linux.intel.com
Reviewed-by: Sean Paul <seanpaul@chromium.org>