Commit 500e1af2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking fixes from Ingo Molnar:

 - Change the new refcount_t warnings from WARN() to WARN_ONCE()

 - two ww_mutex fixes

 - plus a new lockdep self-consistency check for a bug that triggered in
   practice

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/ww_mutex: Adjust the lock number for stress test
  locking/lockdep: Add nest_lock integrity test
  locking/ww_mutex: Replace cpu_relax() with cond_resched() for tests
  locking/refcounts: Change WARN() to WARN_ONCE()
parents 26db8f99 857811a3

kernel/locking/lockdep.c

+9 −2
Original line number Diff line number Diff line
@@ -3262,10 +3262,17 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, 
	if (depth) {

		hlock = curr->held_locks + depth - 1;

		if (hlock->class_idx == class_idx && nest_lock) {

			if (hlock->references)

			if (hlock->references) {

				/*

				 * Check: unsigned int references:12, overflow.

				 */

				if (DEBUG_LOCKS_WARN_ON(hlock->references == (1 << 12)-1))

					return 0;



				hlock->references++;

			else

			} else {

				hlock->references = 2;

			}



			return 1;

		}

kernel/locking/test-ww_mutex.c

+3 −3
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ static void test_mutex_work(struct work_struct *work) 


	if (mtx->flags & TEST_MTX_TRY) {

		while (!ww_mutex_trylock(&mtx->mutex))

			cpu_relax();

			cond_resched();

	} else {

		ww_mutex_lock(&mtx->mutex, NULL);

	}
@@ -88,7 +88,7 @@ static int __test_mutex(unsigned int flags) 
				ret = -EINVAL;

				break;

			}

			cpu_relax();

			cond_resched();

		} while (time_before(jiffies, timeout));

	} else {

		ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
@@ -627,7 +627,7 @@ static int __init test_ww_mutex_init(void) 
	if (ret)

		return ret;



	ret = stress(4096, hweight32(STRESS_ALL)*ncpus, 1<<12, STRESS_ALL);

	ret = stress(4095, hweight32(STRESS_ALL)*ncpus, 1<<12, STRESS_ALL);

	if (ret)

		return ret;

lib/refcount.c

+7 −7
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ bool refcount_add_not_zero(unsigned int i, refcount_t *r) 
		val = old;

	}



	WARN(new == UINT_MAX, "refcount_t: saturated; leaking memory.\n");

	WARN_ONCE(new == UINT_MAX, "refcount_t: saturated; leaking memory.\n");



	return true;

}
@@ -66,7 +66,7 @@ EXPORT_SYMBOL_GPL(refcount_add_not_zero); 


void refcount_add(unsigned int i, refcount_t *r)

{

	WARN(!refcount_add_not_zero(i, r), "refcount_t: addition on 0; use-after-free.\n");

	WARN_ONCE(!refcount_add_not_zero(i, r), "refcount_t: addition on 0; use-after-free.\n");

}

EXPORT_SYMBOL_GPL(refcount_add);
@@ -97,7 +97,7 @@ bool refcount_inc_not_zero(refcount_t *r) 
		val = old;

	}



	WARN(new == UINT_MAX, "refcount_t: saturated; leaking memory.\n");

	WARN_ONCE(new == UINT_MAX, "refcount_t: saturated; leaking memory.\n");



	return true;

}
@@ -111,7 +111,7 @@ EXPORT_SYMBOL_GPL(refcount_inc_not_zero); 
 */

void refcount_inc(refcount_t *r)

{

	WARN(!refcount_inc_not_zero(r), "refcount_t: increment on 0; use-after-free.\n");

	WARN_ONCE(!refcount_inc_not_zero(r), "refcount_t: increment on 0; use-after-free.\n");

}

EXPORT_SYMBOL_GPL(refcount_inc);
@@ -125,7 +125,7 @@ bool refcount_sub_and_test(unsigned int i, refcount_t *r) 


		new = val - i;

		if (new > val) {

			WARN(new > val, "refcount_t: underflow; use-after-free.\n");

			WARN_ONCE(new > val, "refcount_t: underflow; use-after-free.\n");

			return false;

		}
@@ -164,7 +164,7 @@ EXPORT_SYMBOL_GPL(refcount_dec_and_test); 


void refcount_dec(refcount_t *r)

{

	WARN(refcount_dec_and_test(r), "refcount_t: decrement hit 0; leaking memory.\n");

	WARN_ONCE(refcount_dec_and_test(r), "refcount_t: decrement hit 0; leaking memory.\n");

}

EXPORT_SYMBOL_GPL(refcount_dec);
@@ -204,7 +204,7 @@ bool refcount_dec_not_one(refcount_t *r) 


		new = val - 1;

		if (new > val) {

			WARN(new > val, "refcount_t: underflow; use-after-free.\n");

			WARN_ONCE(new > val, "refcount_t: underflow; use-after-free.\n");

			return true;

		}

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