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authorByungchul Park <byungchul.park@lge.com>2017-08-07 10:12:56 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:29:10 +0300
commitcd8084f91c02c1afd256a39aa833bff737631304 (patch)
treea2eb7a1ce13798602affca1f244dbccc583b3952 /include/linux/completion.h
parent383a4bc88849b804385162e81bf704f8f9690a87 (diff)
downloadlinux-cd8084f91c02c1afd256a39aa833bff737631304.tar.xz
locking/lockdep: Apply crossrelease to completions
Although wait_for_completion() and its family can cause deadlock, the lock correctness validator could not be applied to them until now, because things like complete() are usually called in a different context from the waiting context, which violates lockdep's assumption. Thanks to CONFIG_LOCKDEP_CROSSRELEASE, we can now apply the lockdep detector to those completion operations. Applied it. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-10-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/completion.h')
-rw-r--r--include/linux/completion.h45
1 files changed, 44 insertions, 1 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 5d5aaae3af43..9bcebf509b4d 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -9,6 +9,9 @@
*/
#include <linux/wait.h>
+#ifdef CONFIG_LOCKDEP_COMPLETE
+#include <linux/lockdep.h>
+#endif
/*
* struct completion - structure used to maintain state for a "completion"
@@ -25,10 +28,50 @@
struct completion {
unsigned int done;
wait_queue_head_t wait;
+#ifdef CONFIG_LOCKDEP_COMPLETE
+ struct lockdep_map_cross map;
+#endif
};
+#ifdef CONFIG_LOCKDEP_COMPLETE
+static inline void complete_acquire(struct completion *x)
+{
+ lock_acquire_exclusive((struct lockdep_map *)&x->map, 0, 0, NULL, _RET_IP_);
+}
+
+static inline void complete_release(struct completion *x)
+{
+ lock_release((struct lockdep_map *)&x->map, 0, _RET_IP_);
+}
+
+static inline void complete_release_commit(struct completion *x)
+{
+ lock_commit_crosslock((struct lockdep_map *)&x->map);
+}
+
+#define init_completion(x) \
+do { \
+ static struct lock_class_key __key; \
+ lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \
+ "(complete)" #x, \
+ &__key, 0); \
+ __init_completion(x); \
+} while (0)
+#else
+#define init_completion(x) __init_completion(x)
+static inline void complete_acquire(struct completion *x) {}
+static inline void complete_release(struct completion *x) {}
+static inline void complete_release_commit(struct completion *x) {}
+#endif
+
+#ifdef CONFIG_LOCKDEP_COMPLETE
+#define COMPLETION_INITIALIZER(work) \
+ { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait), \
+ STATIC_CROSS_LOCKDEP_MAP_INIT("(complete)" #work, &(work)) }
+#else
#define COMPLETION_INITIALIZER(work) \
{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+#endif
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
@@ -70,7 +113,7 @@ struct completion {
* This inline function will initialize a dynamically created completion
* structure.
*/
-static inline void init_completion(struct completion *x)
+static inline void __init_completion(struct completion *x)
{
x->done = 0;
init_waitqueue_head(&x->wait);