drm/i915: Make i915_pipe_crc_read() oops proof
Currently i915_pipe_crc_read() will drop pipe_crc->lock for the entire duration of the copy_to_user() loop, which means it'll access pipe_crc->entries without any protection. If another thread sneaks in and frees pipe_crc->entries the code will oops. Reorganize the code to hold the lock around everything except copy_to_user(). After the copy the lock is reacquired and the the number of available entries is rechecked. Since this is a debug feature simplify the error handling a bit by consuming the crc entry even if copy_to_user() would fail. Signed-off-by:Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch>
parent
3cf54b34
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