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authorDavidlohr Bueso2019-07-28 21:47:35 -0700
committerPeter Zijlstra2019-08-06 12:49:15 +0200
commitfce45cd41101f1a9620267146b21f09b3454d8db (patch)
treeff8142e67c6ec7cb5d6ed8aa0a7e662bfe57ce1a /include/linux/rwsem.h
parent91d2a812dfb98b3b4dad661529c33bc38d303461 (diff)
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.h10
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) \