locking/lockdep: Add nest_lock integrity test
[ Upstream commit 7fb4a2cea6
]
Boqun reported that hlock->references can overflow. Add a debug test
for that to generate a clear error when this happens.
Without this, lockdep is likely to report a mysterious failure on
unlock.
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
steinar/wifi_calib_4_9_kernel
parent
43588be073
commit
8b0be545de
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@ -3260,10 +3260,17 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
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if (depth) {
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hlock = curr->held_locks + depth - 1;
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if (hlock->class_idx == class_idx && nest_lock) {
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if (hlock->references)
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if (hlock->references) {
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/*
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* Check: unsigned int references:12, overflow.
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*/
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if (DEBUG_LOCKS_WARN_ON(hlock->references == (1 << 12)-1))
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return 0;
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hlock->references++;
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else
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} else {
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hlock->references = 2;
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}
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return 1;
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}
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