locking/lockdep: Avoid unmatched unlock

Commit f6f48e180404 ("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: f6f48e180404 ("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

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index ad9afd8c7eb9e9ad6655a7b5d69c305bfb571699..5104db0e23e44f3674f9e7f7cb4f9dc8ea021aa6 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -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;
        }