[PATCH 02/14] cleanup: Disable context analysis for __free() helpers

[Bart Van Assche]

The __free_##_name() helper functions defined by DEFINE_FREE() call the
free expression that has been passed to DEFINE_FREE(). If that
expression releases a lock, e.g. because it is a call to an unlock
function, the Clang thread-safety analyzer complains because it cannot
know that the variable that is passed to the helper function holds a
lock. Hence, disable context analysis for the __free() helper
functions.

Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 include/linux/cleanup.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index 1fb8058b897d..f6afe80781a4 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -207,8 +207,10 @@
  * Without the NULL test it turns into a mess and the compiler can't help us.
  */
 
-#define DEFINE_FREE(_name, _type, _free) \
-	static __always_inline void __free_##_name(void *p) { _type _T = *(_type *)p; _free; }
+#define DEFINE_FREE(_name, _type, _free)				\
+	static __always_inline void __free_##_name(void *p)		\
+		__context_unsafe(/* _free may release a lock */)		\
+	{ _type _T = *(_type *)p; _free; }
 
 #define __free(_name)	__cleanup(__free_##_name)