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authorJ. R. Okajima <hooanon05g@gmail.com>2017-02-03 01:38:17 +0900
committerIngo Molnar <mingo@kernel.org>2017-03-16 09:57:07 +0100
commit6419c4af777a773a45a1b1af735de0fcd9a7dcc7 (patch)
tree0f7d44f45b63043b15904ac5f755bbb0abddb7bc /kernel/locking/rwsem.c
parente969970be033841d4c16b2e8ec8a3608347db861 (diff)
locking/lockdep: Add new check to lock_downgrade()
Commit: f8319483f57f ("locking/lockdep: Provide a type check for lock_is_held") didn't fully cover rwsems as downgrade_write() was left out. Introduce lock_downgrade() and use it to add new checks. See-also: http://marc.info/?l=linux-kernel&m=148581164003149&w=2 Originally-written-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1486053497-9948-3-git-send-email-hooanon05g@gmail.com [ Rewrote the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/rwsem.c')
-rw-r--r--kernel/locking/rwsem.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 90a74ccd85a4..4d48b1c4870d 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -124,10 +124,8 @@ EXPORT_SYMBOL(up_write);
*/
void downgrade_write(struct rw_semaphore *sem)
{
- /*
- * lockdep: a downgraded write will live on as a write
- * dependency.
- */
+ lock_downgrade(&sem->dep_map, _RET_IP_);
+
rwsem_set_reader_owned(sem);
__downgrade_write(sem);
}