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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-08-11 07:30:21 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-08-11 07:30:21 (GMT) |
commit | 64aa348edc617dea17bbd01ddee4e47886d5ec8c (patch) | |
tree | 002b5fa796aff225d0cb9d0c32bb3ba96da6eaaf /kernel/lockdep.c | |
parent | 5e710e37bde120bb069f691bee68e69ef4393173 (diff) | |
download | linux-fsl-qoriq-64aa348edc617dea17bbd01ddee4e47886d5ec8c.tar.xz |
lockdep: lock_set_subclass - reset a held lock's subclass
this can be used to reset a held lock's subclass, for arbitrary-depth
iterated data structures such as trees or lists which have per-node
locks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/lockdep.c')
-rw-r--r-- | kernel/lockdep.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 6999e64..e14d383 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2660,6 +2660,55 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock, return 1; } +static int +__lock_set_subclass(struct lockdep_map *lock, + unsigned int subclass, unsigned long ip) +{ + struct task_struct *curr = current; + struct held_lock *hlock, *prev_hlock; + struct lock_class *class; + unsigned int depth; + int i; + + depth = curr->lockdep_depth; + if (DEBUG_LOCKS_WARN_ON(!depth)) + return 0; + + prev_hlock = NULL; + for (i = depth-1; i >= 0; i--) { + hlock = curr->held_locks + i; + /* + * We must not cross into another context: + */ + if (prev_hlock && prev_hlock->irq_context != hlock->irq_context) + break; + if (hlock->instance == lock) + goto found_it; + prev_hlock = hlock; + } + return print_unlock_inbalance_bug(curr, lock, ip); + +found_it: + class = register_lock_class(lock, subclass, 0); + hlock->class = class; + + curr->lockdep_depth = i; + curr->curr_chain_key = hlock->prev_chain_key; + + for (; i < depth; i++) { + hlock = curr->held_locks + i; + if (!__lock_acquire(hlock->instance, + hlock->class->subclass, hlock->trylock, + hlock->read, hlock->check, hlock->hardirqs_off, + hlock->acquire_ip)) + return 0; + } + + if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth)) + return 0; + return 1; +} + /* * Remove the lock to the list of currently held locks in a * potentially non-nested (out of order) manner. This is a @@ -2824,6 +2873,26 @@ static void check_flags(unsigned long flags) #endif } +void +lock_set_subclass(struct lockdep_map *lock, + unsigned int subclass, unsigned long ip) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + current->lockdep_recursion = 1; + check_flags(flags); + if (__lock_set_subclass(lock, subclass, ip)) + check_chain_key(current); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} + +EXPORT_SYMBOL_GPL(lock_set_subclass); + /* * We are not always called with irqs disabled - do that here, * and also avoid lockdep recursion: |