[PATCH 3.16 20/86] jump_label: make static_key_enabled() work on static_key_true/false types too

Ben Hutchings
2019-05-16T15:58:56Z

From: Tejun Heo <tj@kernel.org>

commit fa128fd735bd236b6b04d3fedfed7a784137c185 upstream.

static_key_enabled() can be used on struct static_key but not on its
wrapper types static_key_true and static_key_false. The function is
useful for debugging and management of static keys. Update it so that
it can be used for the wrapper types too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
include/linux/jump_label.h | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -214,11 +214,6 @@ static inline int jump_label_apply_nops(
#define STATIC_KEY_INIT STATIC_KEY_INIT_FALSE
#define jump_label_enabled static_key_enabled

-static inline bool static_key_enabled(struct static_key *key)
-{
- return static_key_count(key) > 0;
-}
-
static inline void static_key_enable(struct static_key *key)
{
int count = static_key_count(key);
@@ -265,6 +260,17 @@ struct static_key_false {
#define DEFINE_STATIC_KEY_FALSE(name) \
struct static_key_false name = STATIC_KEY_FALSE_INIT

+extern bool ____wrong_branch_error(void);
+
+#define static_key_enabled(x) \
+({ \
+ if (!__builtin_types_compatible_p(typeof(*x), struct static_key) && \
+ !__builtin_types_compatible_p(typeof(*x), struct static_key_true) &&\
+ !__builtin_types_compatible_p(typeof(*x), struct static_key_false)) \
+ ____wrong_branch_error(); \
+ static_key_count((struct static_key *)x) > 0; \
+})
+
#ifdef HAVE_JUMP_LABEL

/*
@@ -323,8 +329,6 @@ struct static_key_false {
* See jump_label_type() / jump_label_init_type().
*/

-extern bool ____wrong_branch_error(void);
-
#define static_branch_likely(x) \
({ \
bool branch; \