From 7f82e631d236cafd28518b998c6d4d8dc2ef68f6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 1 Feb 2021 11:55:38 +0100 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lkml.kernel.org/r/YBfkuyIfB1+VRxXP@hirez.programming.kicks-ass.net --- kernel/locking/lockdep.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index ad9afd8c7eb9..5104db0e23e4 100644 --- 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; } -- 2.25.1