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| author | Davidlohr Bueso <dave@stgolabs.net> | 2019-07-28 21:47:35 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2019-08-06 12:49:15 +0200 |
| commit | fce45cd41101f1a9620267146b21f09b3454d8db (patch) | |
| tree | ff8142e67c6ec7cb5d6ed8aa0a7e662bfe57ce1a /include/linux/rwsem.h | |
| parent | 91d2a812dfb98b3b4dad661529c33bc38d303461 (diff) | |
| download | lwn-fce45cd41101f1a9620267146b21f09b3454d8db.tar.gz lwn-fce45cd41101f1a9620267146b21f09b3454d8db.zip | |
locking/rwsem: Check for operations on an uninitialized rwsem
Currently rwsems is the only locking primitive that lacks this
debug feature. Add it under CONFIG_DEBUG_RWSEMS and do the magic
checking in the locking fastpath (trylock) operation such that
we cover all cases. The unlocking part is pretty straightforward.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: mingo@kernel.org
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lkml.kernel.org/r/20190729044735.9632-1-dave@stgolabs.net
Diffstat (limited to 'include/linux/rwsem.h')
| -rw-r--r-- | include/linux/rwsem.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 9d9c663987d8..00d6054687dd 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -45,6 +45,9 @@ struct rw_semaphore { #endif raw_spinlock_t wait_lock; struct list_head wait_list; +#ifdef CONFIG_DEBUG_RWSEMS + void *magic; +#endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif @@ -73,6 +76,12 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) # define __RWSEM_DEP_MAP_INIT(lockname) #endif +#ifdef CONFIG_DEBUG_RWSEMS +# define __DEBUG_RWSEM_INITIALIZER(lockname) , .magic = &lockname +#else +# define __DEBUG_RWSEM_INITIALIZER(lockname) +#endif + #ifdef CONFIG_RWSEM_SPIN_ON_OWNER #define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED #else @@ -85,6 +94,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) .wait_list = LIST_HEAD_INIT((name).wait_list), \ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \ __RWSEM_OPT_INIT(name) \ + __DEBUG_RWSEM_INITIALIZER(name) \ __RWSEM_DEP_MAP_INIT(name) } #define DECLARE_RWSEM(name) \ |