posix-timers: Annotate lock_timer()

lock_timer() conditionally grabs it_lock in case of returning non-NULL
but unlock_timer() releases it unconditionally. This leads sparse to
complain about the lock context imbalance. Rename and wrap lock_timer
using __cond_lock() macro to make sparse happy.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 2 deletions

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 9ca4973f736d..93bd2eb2bc53 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -145,7 +145,13 @@ static int common_timer_del(struct k_itimer *timer);
 
 static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
 
-static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);
+static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
+
+#define lock_timer(tid, flags)                                             \
+({      struct k_itimer *__timr;                                           \
+        __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags));  \
+        __timr;                                                            \
+})
 
 static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
 {
@@ -619,7 +625,7 @@ out:
  * the find to the timer lock.  To avoid a dead lock, the timer id MUST
  * be release with out holding the timer lock.
  */
-static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags)
+static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
 {
         struct k_itimer *timr;
         /*