From 4957089a23f41f31f8e7e22802a8ef9f5789c191 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 8 Sep 2025 18:00:02 -0700 Subject: locking/local_lock: Introduce local_lock_is_locked(). Introduce local_lock_is_locked() that returns true when given local_lock is locked by current cpu (in !PREEMPT_RT) or by current task (in PREEMPT_RT). The goal is to detect a deadlock by the caller. Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: Alexei Starovoitov Signed-off-by: Vlastimil Babka --- include/linux/local_lock_internal.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/local_lock_internal.h') diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index 949de37700db..a4dc479157b5 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -165,6 +165,9 @@ do { \ !!tl; \ }) +/* preemption or migration must be disabled before calling __local_lock_is_locked */ +#define __local_lock_is_locked(lock) READ_ONCE(this_cpu_ptr(lock)->acquired) + #define __local_lock_release(lock) \ do { \ local_trylock_t *tl; \ @@ -285,4 +288,8 @@ do { \ __local_trylock(lock); \ }) +/* migration must be disabled before calling __local_lock_is_locked */ +#define __local_lock_is_locked(__lock) \ + (rt_mutex_owner(&this_cpu_ptr(__lock)->lock) == current) + #endif /* CONFIG_PREEMPT_RT */ -- cgit v1.2.3