diff options
| -rw-r--r-- | include/linux/percpu-refcount.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index d5c89e0dd0e6..51ce60c35f4c 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -133,7 +133,13 @@ static inline bool __ref_is_percpu(struct percpu_ref *ref, /* paired with smp_store_release() in percpu_ref_reinit() */ smp_read_barrier_depends(); - if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC)) + /* + * Theoretically, the following could test just ATOMIC; however, + * then we'd have to mask off DEAD separately as DEAD may be + * visible without ATOMIC if we race with percpu_ref_kill(). DEAD + * implies ATOMIC anyway. Test them together. + */ + if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC_DEAD)) return false; *percpu_countp = (unsigned long __percpu *)percpu_ptr; |