[PATCH v1 1/3] perf mutex: Add annotations for LOCKS_EXCLUDED and LOCKS_RETURNED

From: Ian Rogers
Date: Thu Mar 13 2025 - 23:08:47 EST


Used to annotate when locks shouldn't be held for a function or if a
function returns a lock that's used by later mutex lock unlock
operations.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/mutex.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/tools/perf/util/mutex.h b/tools/perf/util/mutex.h
index 40661120cacc..62d258c71ded 100644
--- a/tools/perf/util/mutex.h
+++ b/tools/perf/util/mutex.h
@@ -33,6 +33,12 @@
/* Documents if a type is a lockable type. */
#define LOCKABLE __attribute__((lockable))

+/* Documents a function that expects a lock not to be held prior to entry. */
+#define LOCKS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
+
+/* Documents a function that returns a lock. */
+#define LOCK_RETURNED(x) __attribute__((lock_returned(x)))
+
/* Documents functions that acquire a lock in the body of a function, and do not release it. */
#define EXCLUSIVE_LOCK_FUNCTION(...) __attribute__((exclusive_lock_function(__VA_ARGS__)))

@@ -57,6 +63,8 @@
#define GUARDED_BY(x)
#define PT_GUARDED_BY(x)
#define LOCKABLE
+#define LOCKS_EXCLUDED(...)
+#define LOCK_RETURNED(x)
#define EXCLUSIVE_LOCK_FUNCTION(...)
#define UNLOCK_FUNCTION(...)
#define EXCLUSIVE_TRYLOCK_FUNCTION(...)
--
2.49.0.rc1.451.g8f38331e32-goog