kernel: time: posix-timers: Pass lockdep expression to RCU lists
PATCH RESEND 1/1 kernel: time: posix-timers: Pass lockdep expression to RCU lists
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.
--- kernel/time/posix-timers.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
kernel/time/posix-timers.c +3 -1
@@ -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; }
Signature · 1 line
2.24.1
[tip: timers/core] posix-timers: Pass lockdep expression to RCU lists
The following commit has been merged into the timers/core branch of tip:
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 9ea9c60fc23c35f865725ab390ca4308de919bb0 Gitweb: https://git.kernel.org/tip/9ea9c60fc23c35f865725ab390ca4308de919bb0 Author: Amol Grover <[email protected]> AuthorDate: Sun, 16 Feb 2020 13:13:30 +05:30 Committer: Thomas Gleixner <[email protected]> CommitterDate: Mon, 17 Feb 2020 16:39:28 +01:00
posix-timers: Pass lockdep expression to RCU lists
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.
[ tglx: Removed the macro and put the condition right where it's used ]
--- kernel/time/posix-timers.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
kernel/time/posix-timers.c +2 -1
@@ -121,7 +121,8 @@ 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, +lockdep_is_held (&hash_lock)) {if ((timer->it_signal == sig) && (timer->it_id == id))return timer; }
[tip: timers/core] posix-timers: Pass lockdep expression to RCU lists
In reply to Amol GroverThe following commit has been merged into the timers/core branch of tip:
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 5fb1c2a5bbf79ccca8d17cf97f66085be5808027 Gitweb: https://git.kernel.org/tip/5fb1c2a5bbf79ccca8d17cf97f66085be5808027 Author: Amol Grover <[email protected]> AuthorDate: Sun, 16 Feb 2020 13:13:30 +05:30 Committer: Thomas Gleixner <[email protected]> CommitterDate: Mon, 17 Feb 2020 20:12:19 +01:00
posix-timers: Pass lockdep expression to RCU lists
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.
[ tglx: Removed the macro and put the condition right where it's used ]
--- kernel/time/posix-timers.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
kernel/time/posix-timers.c +2 -1
@@ -121,7 +121,8 @@ 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, +lockdep_is_held (&hash_lock)) {if ((timer->it_signal == sig) && (timer->it_id == id))return timer; }