svn commit: r309784 - head/sys/kern
Mark Johnston
markj at FreeBSD.org
Sat Dec 10 02:59:36 UTC 2016
Author: markj
Date: Sat Dec 10 02:59:34 2016
New Revision: 309784
URL: https://svnweb.freebsd.org/changeset/base/309784
Log:
Use a consistent snapshot of the lock state in owner_mtx().
MFC after: 2 weeks
Modified:
head/sys/kern/kern_mutex.c
Modified: head/sys/kern/kern_mutex.c
==============================================================================
--- head/sys/kern/kern_mutex.c Sat Dec 10 02:56:44 2016 (r309783)
+++ head/sys/kern/kern_mutex.c Sat Dec 10 02:59:34 2016 (r309784)
@@ -249,10 +249,13 @@ unlock_spin(struct lock_object *lock)
int
owner_mtx(const struct lock_object *lock, struct thread **owner)
{
- const struct mtx *m = (const struct mtx *)lock;
+ const struct mtx *m;
+ uintptr_t x;
- *owner = mtx_owner(m);
- return (mtx_unowned(m) == 0);
+ m = (const struct mtx *)lock;
+ x = m->mtx_lock;
+ *owner = (struct thread *)(x & ~MTX_FLAGMASK);
+ return (x != MTX_UNOWNED);
}
#endif
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