[tip: locking/core] lockdep: Fix wait-type for empty stack

From: tip-bot2 for Peter Zijlstra
Date: Wed Jun 23 2021 - 04:19:30 EST


The following commit has been merged into the locking/core branch of tip:

Commit-ID: f8b298cc39f0619544c607eaef09fd0b2afd10f3
Gitweb: https://git.kernel.org/tip/f8b298cc39f0619544c607eaef09fd0b2afd10f3
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 17 Jun 2021 20:57:18 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 22 Jun 2021 16:42:08 +02:00

lockdep: Fix wait-type for empty stack

Even the very first lock can violate the wait-context check, consider
the various IRQ contexts.

Fixes: de8f5e4f2dc1 ("lockdep: Introduce wait-type checks")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Tested-by: Joerg Roedel <jroedel@xxxxxxx>
Link: https://lore.kernel.org/r/20210617190313.256987481@xxxxxxxxxxxxx
---
kernel/locking/lockdep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 6ff1e84..0584b20 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4688,7 +4688,7 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next)
u8 curr_inner;
int depth;

- if (!curr->lockdep_depth || !next_inner || next->trylock)
+ if (!next_inner || next->trylock)
return 0;

if (!next_outer)