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locking/lockdep: Avoid unmatched unlock

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Commit f6f48e1804 ("lockdep: Teach lockdep about "USED" <- "IN-NMI"
inversions") overlooked that print_usage_bug() releases the graph_lock
and called it without the graph lock held.

Fixes: f6f48e1804 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/YBfkuyIfB1+VRxXP@hirez.programming.kicks-ass.net
This commit is contained in:
Peter Zijlstra 2021-02-01 11:55:38 +01:00
parent 442187f3c2
commit 7f82e631d2
1 changed files with 2 additions and 1 deletions
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3
kernel/locking/lockdep.c
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@ -3773,7 +3773,7 @@ static void
print_usage_bug(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
{
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
if (!debug_locks_off() || debug_locks_silent)
return;
pr_warn("\n");
@ -3814,6 +3814,7 @@ valid_state(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
{
if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) {
graph_unlock();
print_usage_bug(curr, this, bad_bit, new_bit);
return 0;
}