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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-07 14:33:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-07 14:33:11 -0800
commit500e1af25209a048daa1f1f86083d4849d5c555b (patch)
tree81dd69220be55d3458f846cd0e1f2c4df116cb66
parent26db8f992444a87465fc01b264b0317a3943e2b6 (diff)
parent857811a37129f5d2ba162d7be3986eff44724014 (diff)
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()
-rw-r--r--kernel/locking/lockdep.c11
-rw-r--r--kernel/locking/test-ww_mutex.c6
-rw-r--r--lib/refcount.c14
3 files changed, 19 insertions, 12 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 12e38c213b70..a95e5d1f4a9c 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -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;
}
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index da6c9a34f62f..6b7abb334ca6 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -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;
diff --git a/lib/refcount.c b/lib/refcount.c
index 1d33366189d1..aa09ad3c30b0 100644
--- a/lib/refcount.c
+++ b/lib/refcount.c
@@ -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;
}