Merge branch 'dev-5.10' into dev-5.10-inteldev-5.10-intel

Pull 5.10.67 stable from OpenBMC upstream.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 716990bace10..42d04607d091 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -226,15 +226,27 @@ struct drm_file {
 	/**
 	 * @master:
 	 *
-	 * Master this node is currently associated with. Only relevant if
-	 * drm_is_primary_client() returns true. Note that this only
-	 * matches &drm_device.master if the master is the currently active one.
+	 * Master this node is currently associated with. Protected by struct
+	 * &drm_device.master_mutex, and serialized by @master_lookup_lock.
+	 *
+	 * Only relevant if drm_is_primary_client() returns true. Note that
+	 * this only matches &drm_device.master if the master is the currently
+	 * active one.
+	 *
+	 * When dereferencing this pointer, either hold struct
+	 * &drm_device.master_mutex for the duration of the pointer's use, or
+	 * use drm_file_get_master() if struct &drm_device.master_mutex is not
+	 * currently held and there is no other need to hold it. This prevents
+	 * @master from being freed during use.
 	 *
 	 * See also @authentication and @is_master and the :ref:`section on
 	 * primary nodes and authentication <drm_primary_node>`.
 	 */
 	struct drm_master *master;
 
+	/** @master_lock: Serializes @master. */
+	spinlock_t master_lookup_lock;
+
 	/** @pid: Process that opened this file. */
 	struct pid *pid;