Messages in this thread Patch in this message | | | Date | Sun, 16 Feb 2020 13:13:30 +0530 | From | Amol Grover <> | Subject | [PATCH RESEND] kernel: time: posix-timers: Pass lockdep expression to RCU lists |
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head is traversed using hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of hash_lock.
Hence, add corresponding lockdep expression to silence false-positive lockdep warnings, and harden RCU lists.
Add macro for the corresponding lockdep expression.
Signed-off-by: Amol Grover <frextrite@gmail.com> --- kernel/time/posix-timers.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 0ec5b7a1d769..2ccce00af177 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -50,6 +50,8 @@ static struct kmem_cache *posix_timers_cache; static DEFINE_HASHTABLE(posix_timers_hashtable, 9); static DEFINE_SPINLOCK(hash_lock); +#define hash_lock_held() \ + lockdep_is_held(&hash_lock) static const struct k_clock * const posix_clocks[]; static const struct k_clock *clockid_to_kclock(const clockid_t id); @@ -120,7 +122,7 @@ static struct k_itimer *__posix_timers_find(struct hlist_head *head, { struct k_itimer *timer; - hlist_for_each_entry_rcu(timer, head, t_hash) { + hlist_for_each_entry_rcu(timer, head, t_hash, hash_lock_held()) { if ((timer->it_signal == sig) && (timer->it_id == id)) return timer; } -- 2.24.1
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