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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-20 10:43:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-20 10:43:27 -0700 |
| commit | 4b65f455c787eeca1a6eb8cc8f590ade6cecb179 (patch) | |
| tree | 0a190c14dd0ac463b97fdb41e37ff6920d1d74f5 /include | |
| parent | 056ad121c26db1cfc8253222e2297fb7b7577fe8 (diff) | |
| parent | 5a817641f68a6399a5fac8b7d2da67a73698ffed (diff) | |
| download | linux-4b65f455c787eeca1a6eb8cc8f590ade6cecb179.tar.gz linux-4b65f455c787eeca1a6eb8cc8f590ade6cecb179.tar.bz2 linux-4b65f455c787eeca1a6eb8cc8f590ade6cecb179.zip | |
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two fixes to address shortcomings of the rwsem/percpu-rwsem lock
debugging code which emits false positive warnings when the rwsem is
anonymously locked and unlocked"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/percpu-rwsem: Annotate rwsem ownership transfer by setting RWSEM_OWNER_UNKNOWN
locking/rwsem: Add a new RWSEM_ANONYMOUSLY_OWNED flag
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/percpu-rwsem.h | 6 | ||||
| -rw-r--r-- | include/linux/rwsem.h | 6 |
2 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index b1f37a89e368..79b99d653e03 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -133,7 +133,7 @@ static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem, lock_release(&sem->rw_sem.dep_map, 1, ip); #ifdef CONFIG_RWSEM_SPIN_ON_OWNER if (!read) - sem->rw_sem.owner = NULL; + sem->rw_sem.owner = RWSEM_OWNER_UNKNOWN; #endif } @@ -141,6 +141,10 @@ static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem, bool read, unsigned long ip) { lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip); +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER + if (!read) + sem->rw_sem.owner = current; +#endif } #endif diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 56707d5ff6ad..ab93b6eae696 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -44,6 +44,12 @@ struct rw_semaphore { #endif }; +/* + * Setting bit 0 of the owner field with other non-zero bits will indicate + * that the rwsem is writer-owned with an unknown owner. + */ +#define RWSEM_OWNER_UNKNOWN ((struct task_struct *)-1L) + extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_down_read_failed_killable(struct rw_semaphore *sem); extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem); |