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authorSean Paul <seanpaul@chromium.org>2017-05-18 09:24:30 -0400
committerSean Paul <seanpaul@chromium.org>2017-05-18 09:24:30 -0400
commit6b7781b42dc9bc9bcd1523b6c24b876cdda0bef3 (patch)
treeee55c67e4ea30b9eb44f301ba0bde2e631a26162 /kernel/rcu/srcu.c
parent52d9d38c183bf0e09601d875ea31bb53c05dd8cf (diff)
parente98c58e55f68f8785aebfab1f8c9a03d8de0afe1 (diff)
Merge remote-tracking branch 'airlied/drm-next' into drm-misc-next
Picking up drm-next @ 4.12-rc1 in order to apply Michal Hocko's vmalloc patch set Signed-off-by: Sean Paul <seanpaul@chromium.org>
Diffstat (limited to 'kernel/rcu/srcu.c')
-rw-r--r--kernel/rcu/srcu.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c
index ef3bcfb15b39..584d8a983883 100644
--- a/kernel/rcu/srcu.c
+++ b/kernel/rcu/srcu.c
@@ -22,7 +22,7 @@
* Lai Jiangshan <laijs@cn.fujitsu.com>
*
* For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU/ *.txt
+ * Documentation/RCU/ *.txt
*
*/
@@ -243,8 +243,14 @@ static bool srcu_readers_active(struct srcu_struct *sp)
* cleanup_srcu_struct - deconstruct a sleep-RCU structure
* @sp: structure to clean up.
*
- * Must invoke this after you are finished using a given srcu_struct that
- * was initialized via init_srcu_struct(), else you leak memory.
+ * Must invoke this only after you are finished using a given srcu_struct
+ * that was initialized via init_srcu_struct(). This code does some
+ * probabalistic checking, spotting late uses of srcu_read_lock(),
+ * synchronize_srcu(), synchronize_srcu_expedited(), and call_srcu().
+ * If any such late uses are detected, the per-CPU memory associated with
+ * the srcu_struct is simply leaked and WARN_ON() is invoked. If the
+ * caller frees the srcu_struct itself, a use-after-free crash will likely
+ * ensue, but at least there will be a warning printed.
*/
void cleanup_srcu_struct(struct srcu_struct *sp)
{