diff mbox series

[2/3] lockdep: add might_lock_nested()

Message ID 20191104173720.2696-2-daniel.vetter@ffwll.ch (mailing list archive)
State New, archived
Headers show
Series [1/3] drm/i915: Switch obj->mm.lock lockdep annotations on its head | expand

Commit Message

Daniel Vetter Nov. 4, 2019, 5:37 p.m. UTC 
Necessary to annotate functions where we might acquire a
mutex_lock_nested() or similar. Needed by i915.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org
---
 include/linux/lockdep.h | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index e0eca94e58c8..c4155436e6fc 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -628,6 +628,13 @@  do {									\
 	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
 	lock_release(&(lock)->dep_map, 0, _THIS_IP_);			\
 } while (0)
+# define might_lock_nested(lock, subclass) 				\
+do {									\
+	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
+	lock_acquire(&(lock)->dep_map, subclass, 0, 1, 1, NULL,		\
+		     _THIS_IP_);					\
+	lock_release(&(lock)->dep_map, 0, _THIS_IP_);		\
+} while (0)
 
 #define lockdep_assert_irqs_enabled()	do {				\
 		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
@@ -650,6 +657,7 @@  do {									\
 #else
 # define might_lock(lock) do { } while (0)
 # define might_lock_read(lock) do { } while (0)
+# define might_lock_nested(lock, subclass) do { } while (0)
 # define lockdep_assert_irqs_enabled() do { } while (0)
 # define lockdep_assert_irqs_disabled() do { } while (0)
 # define lockdep_assert_in_irq() do { } while (0)