This patch adds lock_class_is_held(), which can be used to assert that a particular type of lock is not held.
Signed-off-by: Kent Overstreet <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Will Deacon <[email protected]> Cc: Waiman Long <[email protected]> Cc: Boqun Feng <[email protected]> --- include/linux/lockdep.h | 4 ++++ kernel/locking/lockdep.c | 20 ++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index dc2844b071c2..fc86557d2a21 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -344,6 +344,8 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c)) #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c)) +int lock_class_is_held(struct lock_class_key *key); + /* * Must use lock_map_aquire_try() with override maps to avoid * lockdep thinking they participate in the block chain. @@ -442,6 +444,8 @@ extern int lockdep_is_held(const void *); #define lockdep_repin_lock(l, c) do { (void)(l); (void)(c); } while (0) #define lockdep_unpin_lock(l, c) do { (void)(l); (void)(c); } while (0) +static inline int lock_class_is_held(struct lock_class_key *key) { return 0; } + #define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \ struct lockdep_map __maybe_unused _name = {} diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e85b5ad3e206..38924d90da85 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -6599,6 +6599,26 @@ void debug_check_no_locks_held(void) } EXPORT_SYMBOL_GPL(debug_check_no_locks_held); +#ifdef CONFIG_LOCKDEP +int lock_class_is_held(struct lock_class_key *key) +{ + struct task_struct *curr = current; + struct held_lock *hlock; + + if (unlikely(!debug_locks)) + return 0; + + for (hlock = curr->held_locks; + hlock < curr->held_locks + curr->lockdep_depth; + hlock++) + if (hlock->instance->key == key) + return 1; + + return 0; +} +EXPORT_SYMBOL_GPL(lock_class_is_held); +#endif + #ifdef __KERNEL__ void debug_show_all_locks(void) { -- 2.42.0
