[PATCH v2 1/2] hrtimer: Add missing annotation to lock_hrtimer_base()

From: Jules Irenge
Date: Sun Jan 26 2020 - 21:30:34 EST


Sparse reports several warnings;

warning: context imbalance in lock_hrtimer_base() - wrong count at exit
warning: context imbalance in hrtimer_start_range_ns() - unexpected unlock
warning: context imbalance in hrtimer_try_to_cancel() - unexpected unlock
warning: context imbalance in __hrtimer_get_remaining() - unexpected unlock

The root cause is a missing annotation of lock_hrtimer_base()
which also causes the "unexpected unlock" warnings.
To fix these,
an __acquires(timer) annotation is added to lock_hrtimer_base().
Given that lock_hrtimer_base() does actually call READ_ONCE(timer->base),
this fixes the warnings.

Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
---
kernel/time/hrtimer.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 8de90ea31280..d149b599bdf7 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -157,9 +157,9 @@ static inline bool is_migration_base(struct hrtimer_clock_base *base)
* possible to set timer->base = &migration_base and drop the lock: the timer
* remains locked.
*/
-static
-struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
- unsigned long *flags)
+static struct hrtimer_clock_base *
+lock_hrtimer_base(const struct hrtimer *timer,
+ unsigned long *flags) __acquires(timer)
{
struct hrtimer_clock_base *base;

--
2.24.1