Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+10
-1
+10
-1
kernel/locking/qspinlock_paravirt.h
+10
-1
kernel/locking/qspinlock_paravirt.h
···
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#include <linux/hash.h>
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#include <linux/bootmem.h>
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+
#include <linux/debug_locks.h>
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/*
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* Implement paravirt qspinlocks; the general idea is to halt the vcpus instead
···
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{
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struct __qspinlock *l = (void *)lock;
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struct pv_node *node;
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u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
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/*
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* We must not unlock if SLOW, because in that case we must first
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* unhash. Otherwise it would be possible to have multiple @lock
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* entries, which would be BAD.
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*/
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-
if (likely(cmpxchg(&l->locked, _Q_LOCKED_VAL, 0) == _Q_LOCKED_VAL))
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if (likely(lockval == _Q_LOCKED_VAL))
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return;
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+
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if (unlikely(lockval != _Q_SLOW_VAL)) {
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if (debug_locks_silent)
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return;
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WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val));
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return;
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}
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/*
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* Since the above failed to release, this must be the SLOW path.