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| author |   Peter Zijlstra <peterz@infradead.org> | 2016-11-30 14:32:25 +1100 |
|---|---|---|
| committer |   Dave Chinner <david@fromorbit.com> | 2016-11-30 14:32:25 +1100 |
| commit | f8319483f57f1ca22370f4150bb990aca7728a67 (patch) | |
| tree | 348cff60f15f3282e5489fba4dfd46b6c958e533 /include/linux/lockdep.h | |
| parent | block: add bio_iov_iter_get_pages() (diff) | |
| download | linux-dev-f8319483f57f1ca22370f4150bb990aca7728a67.tar.xz linux-dev-f8319483f57f1ca22370f4150bb990aca7728a67.zip | |
locking/lockdep: Provide a type check for lock_is_held
Christoph requested lockdep_assert_held() variants that distinguish
between held-for-read or held-for-write.
Provide:
int lock_is_held_type(struct lockdep_map *lock, int read)
which takes the same argument as lock_acquire(.read) and matches it to
the held_lock instance.
Use of this function should be gated by the debug_locks variable. When
that is 0 the return value of the lock_is_held_type() function is
undefined. This is done to allow both negative and positive tests for
holding locks.
By default we provide (positive) lockdep_assert_held{,_exclusive,_read}()
macros.
Requested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'include/linux/lockdep.h')
| -rw-r--r-- | include/linux/lockdep.h | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index c1458fede1f9..1e327bb80838 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -338,9 +338,18 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass, extern void lock_release(struct lockdep_map *lock, int nested, unsigned long ip); -#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map) +/* + * Same "read" as for lock_acquire(), except -1 means any. + */ +extern int lock_is_held_type(struct lockdep_map *lock, int read); + +static inline int lock_is_held(struct lockdep_map *lock) +{ + return lock_is_held_type(lock, -1); +} -extern int lock_is_held(struct lockdep_map *lock); +#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map) +#define lockdep_is_held_type(lock, r) lock_is_held_type(&(lock)->dep_map, (r)) extern void lock_set_class(struct lockdep_map *lock, const char *name, struct lock_class_key *key, unsigned int subclass, @@ -372,6 +381,14 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); WARN_ON(debug_locks && !lockdep_is_held(l)); \ } while (0) +#define lockdep_assert_held_exclusive(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ + } while (0) + +#define lockdep_assert_held_read(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held_type(l, 1)); \ + } while (0) + #define lockdep_assert_held_once(l) do { \ WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \ } while (0) @@ -428,7 +445,11 @@ struct lock_class_key { }; #define lockdep_depth(tsk) (0) +#define lockdep_is_held_type(l, r) (1) + #define lockdep_assert_held(l) do { (void)(l); } while (0) +#define lockdep_assert_held_exclusive(l) do { (void)(l); } while (0) +#define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) #define lockdep_recursing(tsk) (0) |