2021-07-31 08:29:03

by Desmond Cheong Zhi Xi

[permalink] [raw]
Subject: [PATCH v2 1/2] locking/lockdep: Provide lockdep_assert{,_once}() helpers

From: Peter Zijlstra <[email protected]>

Extract lockdep_assert{,_once}() helpers to more easily write composite
assertions like, for example:

lockdep_assert(lockdep_is_held(&drm_device.master_mutex) ||
lockdep_is_held(&drm_file.master_lookup_lock));

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Desmond Cheong Zhi Xi <[email protected]>
Acked-by: Boqun Feng <[email protected]>
Acked-by: Waiman Long <[email protected]>
---
include/linux/lockdep.h | 41 +++++++++++++++++++++--------------------
1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 5cf387813754..9fe165beb0f9 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -306,31 +306,29 @@ 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) == LOCK_STATE_NOT_HELD); \
- } while (0)
+#define lockdep_assert(cond) \
+ do { WARN_ON(debug_locks && !(cond)); } while (0)

-#define lockdep_assert_not_held(l) do { \
- WARN_ON(debug_locks && \
- lockdep_is_held(l) == LOCK_STATE_HELD); \
- } while (0)
+#define lockdep_assert_once(cond) \
+ do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)

-#define lockdep_assert_held_write(l) do { \
- WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \
- } while (0)
+#define lockdep_assert_held(l) \
+ lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)

-#define lockdep_assert_held_read(l) do { \
- WARN_ON(debug_locks && !lockdep_is_held_type(l, 1)); \
- } while (0)
+#define lockdep_assert_not_held(l) \
+ lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)

-#define lockdep_assert_held_once(l) do { \
- WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \
- } while (0)
+#define lockdep_assert_held_write(l) \
+ lockdep_assert(lockdep_is_held_type(l, 0))

-#define lockdep_assert_none_held_once() do { \
- WARN_ON_ONCE(debug_locks && current->lockdep_depth); \
- } while (0)
+#define lockdep_assert_held_read(l) \
+ lockdep_assert(lockdep_is_held_type(l, 1))
+
+#define lockdep_assert_held_once(l) \
+ lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
+
+#define lockdep_assert_none_held_once() \
+ lockdep_assert_once(!current->lockdep_depth)

#define lockdep_recursing(tsk) ((tsk)->lockdep_recursion)

@@ -407,6 +405,9 @@ extern int lock_is_held(const void *);
extern int lockdep_is_held(const void *);
#define lockdep_is_held_type(l, r) (1)

+#define lockdep_assert(c) do { } while (0)
+#define lockdep_assert_once(c) do { } while (0)
+
#define lockdep_assert_held(l) do { (void)(l); } while (0)
#define lockdep_assert_not_held(l) do { (void)(l); } while (0)
#define lockdep_assert_held_write(l) do { (void)(l); } while (0)
--
2.25.1



2021-08-02 09:51:49

by Maarten Lankhorst

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] locking/lockdep: Provide lockdep_assert{,_once}() helpers

Op 31-07-2021 om 10:24 schreef Desmond Cheong Zhi Xi:
> From: Peter Zijlstra <[email protected]>
>
> Extract lockdep_assert{,_once}() helpers to more easily write composite
> assertions like, for example:
>
> lockdep_assert(lockdep_is_held(&drm_device.master_mutex) ||
> lockdep_is_held(&drm_file.master_lookup_lock));
>
> Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
> Signed-off-by: Desmond Cheong Zhi Xi <[email protected]>
> Acked-by: Boqun Feng <[email protected]>
> Acked-by: Waiman Long <[email protected]>
> ---
> include/linux/lockdep.h | 41 +++++++++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 20 deletions(-)
>
> diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
> index 5cf387813754..9fe165beb0f9 100644
> --- a/include/linux/lockdep.h
> +++ b/include/linux/lockdep.h
> @@ -306,31 +306,29 @@ 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) == LOCK_STATE_NOT_HELD); \
> - } while (0)
> +#define lockdep_assert(cond) \
> + do { WARN_ON(debug_locks && !(cond)); } while (0)
>
> -#define lockdep_assert_not_held(l) do { \
> - WARN_ON(debug_locks && \
> - lockdep_is_held(l) == LOCK_STATE_HELD); \
> - } while (0)
> +#define lockdep_assert_once(cond) \
> + do { WARN_ON_ONCE(debug_locks && !(cond)); } while (0)
>
> -#define lockdep_assert_held_write(l) do { \
> - WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \
> - } while (0)
> +#define lockdep_assert_held(l) \
> + lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
>
> -#define lockdep_assert_held_read(l) do { \
> - WARN_ON(debug_locks && !lockdep_is_held_type(l, 1)); \
> - } while (0)
> +#define lockdep_assert_not_held(l) \
> + lockdep_assert(lockdep_is_held(l) != LOCK_STATE_HELD)
>
> -#define lockdep_assert_held_once(l) do { \
> - WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \
> - } while (0)
> +#define lockdep_assert_held_write(l) \
> + lockdep_assert(lockdep_is_held_type(l, 0))
>
> -#define lockdep_assert_none_held_once() do { \
> - WARN_ON_ONCE(debug_locks && current->lockdep_depth); \
> - } while (0)
> +#define lockdep_assert_held_read(l) \
> + lockdep_assert(lockdep_is_held_type(l, 1))
> +
> +#define lockdep_assert_held_once(l) \
> + lockdep_assert_once(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
> +
> +#define lockdep_assert_none_held_once() \
> + lockdep_assert_once(!current->lockdep_depth)
>
> #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion)
>
> @@ -407,6 +405,9 @@ extern int lock_is_held(const void *);
> extern int lockdep_is_held(const void *);
> #define lockdep_is_held_type(l, r) (1)
>
> +#define lockdep_assert(c) do { } while (0)
> +#define lockdep_assert_once(c) do { } while (0)
> +
> #define lockdep_assert_held(l) do { (void)(l); } while (0)
> #define lockdep_assert_not_held(l) do { (void)(l); } while (0)
> #define lockdep_assert_held_write(l) do { (void)(l); } while (0)

All other macros seem to do (void)(c); in this case?


Otherwise looks good.