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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-14 10:45:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-14 10:45:23 -0700 |
| commit | 5e5013c6b5150b8009d980d72495a55b79bf5134 (patch) | |
| tree | 72be7a1f1a5473285c15d76eaaa78aa8cfaead8f /kernel | |
| parent | c679765416705db4788902d74ca8d5edcd4cb816 (diff) | |
| parent | cba77f03f2c7b6cc0b0a44a3c679e0abade7da62 (diff) | |
| download | linux-5e5013c6b5150b8009d980d72495a55b79bf5134.tar.gz | |
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Ingo Molnar: "A single fix for a locking self-test crash" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/pvqspinlock: Fix kernel panic in locking-selftest
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/locking/qspinlock_paravirt.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 04ab18151cc8..df19ae4debd0 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -4,6 +4,7 @@ #include <linux/hash.h> #include <linux/bootmem.h> +#include <linux/debug_locks.h> /* * Implement paravirt qspinlocks; the general idea is to halt the vcpus instead @@ -286,15 +287,23 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; struct pv_node *node; + u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0); /* * We must not unlock if SLOW, because in that case we must first * unhash. Otherwise it would be possible to have multiple @lock * entries, which would be BAD. */ - if (likely(cmpxchg(&l->locked, _Q_LOCKED_VAL, 0) == _Q_LOCKED_VAL)) + if (likely(lockval == _Q_LOCKED_VAL)) return; + if (unlikely(lockval != _Q_SLOW_VAL)) { + if (debug_locks_silent) + return; + WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val)); + return; + } + /* * Since the above failed to release, this must be the SLOW path. * Therefore start by looking up the blocked node and unhashing it. |