From 9ad6d99f189c274b42bedd6efc2b31a17ce733a7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 9 Dec 2014 21:28:32 +0200 Subject: [PATCH] drm/i915: Make i915_pipe_crc_read() oops proof MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Daniel Vetter --- Reading git-format-patch failed