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authorIngo Molnar <mingo@kernel.org>2016-02-09 12:03:15 +0100
committerIngo Molnar <mingo@kernel.org>2016-02-09 12:03:15 +0100
commit3aa6b46c6d6d0f89395ec3811a77fe22e57fa0d3 (patch)
tree12f0563b9b4915ad1b43488df21709dfac287f37 /kernel
parent975db45e9cc561bf8a7eddfa0705d3a078ec184f (diff)
parent8a5fd56431fe1682e870bd6ab0c276e74befbeb9 (diff)
downloadblackbird-op-linux-3aa6b46c6d6d0f89395ec3811a77fe22e57fa0d3.tar.gz
blackbird-op-linux-3aa6b46c6d6d0f89395ec3811a77fe22e57fa0d3.zip
Merge branch 'locking/urgent' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/locking/lockdep.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 60ace56618f6..c7710e4092ef 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1822,7 +1822,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
*/
static int
check_prev_add(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next, int distance, int trylock_loop)
+ struct held_lock *next, int distance, int *stack_saved)
{
struct lock_list *entry;
int ret;
@@ -1883,8 +1883,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
}
}
- if (!trylock_loop && !save_trace(&trace))
- return 0;
+ if (!*stack_saved) {
+ if (!save_trace(&trace))
+ return 0;
+ *stack_saved = 1;
+ }
/*
* Ok, all validations passed, add the new lock
@@ -1907,6 +1910,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
* Debugging printouts:
*/
if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
+ /* We drop graph lock, so another thread can overwrite trace. */
+ *stack_saved = 0;
graph_unlock();
printk("\n new dependency: ");
print_lock_name(hlock_class(prev));
@@ -1929,7 +1934,7 @@ static int
check_prevs_add(struct task_struct *curr, struct held_lock *next)
{
int depth = curr->lockdep_depth;
- int trylock_loop = 0;
+ int stack_saved = 0;
struct held_lock *hlock;
/*
@@ -1956,7 +1961,7 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
*/
if (hlock->read != 2 && hlock->check) {
if (!check_prev_add(curr, hlock, next,
- distance, trylock_loop))
+ distance, &stack_saved))
return 0;
/*
* Stop after the first non-trylock entry,
@@ -1979,7 +1984,6 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
if (curr->held_locks[depth].irq_context !=
curr->held_locks[depth-1].irq_context)
break;
- trylock_loop = 1;
}
return 1;
out_bug:
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