From: Thomas Gleixner tglx@linutronix.de
[ Upstream commit d8bbd97ad0b99a9394f2cd8410b884c48e218cf0 ]
If CONFIG_DEBUG_LOCK_ALLOC=y is enabled then local_lock_t has an 'owner' member which is checked for consistency, but nothing initialized it to zero explicitly.
The static initializer does so implicit, and the run time allocated per CPU storage is usually zero initialized as well, but relying on that is not really good practice.
Fixes: 91710728d172 ("locking: Introduce local_lock()") Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/20210815211301.969975279@linutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/local_lock_internal.h | 42 ++++++++++++++++------------- 1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index ded90b097e6e..3f02b818625e 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -14,29 +14,14 @@ typedef struct { } local_lock_t;
#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define LL_DEP_MAP_INIT(lockname) \ +# define LOCAL_LOCK_DEBUG_INIT(lockname) \ .dep_map = { \ .name = #lockname, \ .wait_type_inner = LD_WAIT_CONFIG, \ - .lock_type = LD_LOCK_PERCPU, \ - } -#else -# define LL_DEP_MAP_INIT(lockname) -#endif - -#define INIT_LOCAL_LOCK(lockname) { LL_DEP_MAP_INIT(lockname) } - -#define __local_lock_init(lock) \ -do { \ - static struct lock_class_key __key; \ - \ - debug_check_no_locks_freed((void *)lock, sizeof(*lock));\ - lockdep_init_map_type(&(lock)->dep_map, #lock, &__key, 0, \ - LD_WAIT_CONFIG, LD_WAIT_INV, \ - LD_LOCK_PERCPU); \ -} while (0) + .lock_type = LD_LOCK_PERCPU, \ + }, \ + .owner = NULL,
-#ifdef CONFIG_DEBUG_LOCK_ALLOC static inline void local_lock_acquire(local_lock_t *l) { lock_map_acquire(&l->dep_map); @@ -51,11 +36,30 @@ static inline void local_lock_release(local_lock_t *l) lock_map_release(&l->dep_map); }
+static inline void local_lock_debug_init(local_lock_t *l) +{ + l->owner = NULL; +} #else /* CONFIG_DEBUG_LOCK_ALLOC */ +# define LOCAL_LOCK_DEBUG_INIT(lockname) static inline void local_lock_acquire(local_lock_t *l) { } static inline void local_lock_release(local_lock_t *l) { } +static inline void local_lock_debug_init(local_lock_t *l) { } #endif /* !CONFIG_DEBUG_LOCK_ALLOC */
+#define INIT_LOCAL_LOCK(lockname) { LOCAL_LOCK_DEBUG_INIT(lockname) } + +#define __local_lock_init(lock) \ +do { \ + static struct lock_class_key __key; \ + \ + debug_check_no_locks_freed((void *)lock, sizeof(*lock));\ + lockdep_init_map_type(&(lock)->dep_map, #lock, &__key, \ + 0, LD_WAIT_CONFIG, LD_WAIT_INV, \ + LD_LOCK_PERCPU); \ + local_lock_debug_init(lock); \ +} while (0) + #define __local_lock(lock) \ do { \ preempt_disable(); \