Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held()
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2021-02-15 13:14:10
Also in:
linux-wireless, lkml
On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote:
I think something like so will work, but please double check.
Yeah, that looks better.
quoted hunk
+++ b/include/linux/lockdep.h@@ -294,11 +294,15 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) -#define lockdep_assert_held(l) do { \ - WARN_ON(debug_locks && !lockdep_is_held(l)); \ +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ } while (0)
That doesn't really need to change? It's the same.
quoted hunk
-#define lockdep_assert_held_write(l) do { \ +#define lockdep_assert_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ + } while (0) + +#define lockdep_assert_held_write(l) do { \ WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ } while (0)diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c1418b47f625..983ba206f7b2 100644 --- a/kernel/locking/lockdep. +++ b/kernel/locking/lockdep.c@@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) int ret = 0; if (unlikely(!lockdep_enabled())) - return 1; /* avoid false negative lockdep_assert_held() */ + return -1; /* avoid false negative lockdep_assert_held() */
Maybe add lockdep_assert_not_held() to the comment, to explain the -1 (vs non-zero)? johannes