Commit 7f82e631 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

locking/lockdep: Avoid unmatched unlock 



Commit f6f48e18 ("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: f6f48e18 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions")
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWaiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/YBfkuyIfB1+VRxXP@hirez.programming.kicks-ass.net
parent 442187f3

kernel/locking/lockdep.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

	}