diff options
| -rw-r--r-- | mm/slab.c | 59 |
1 files changed, 48 insertions, 11 deletions
diff --git a/mm/slab.c b/mm/slab.c index 3936af34454..85c2e03098a 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1021,7 +1021,8 @@ static void drain_alien_cache(struct kmem_cache *cachep, } } -static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp, + int nesting) { struct slab *slabp = virt_to_slab(objp); int nodeid = slabp->nodeid; @@ -1039,7 +1040,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) STATS_INC_NODEFREES(cachep); if (l3->alien && l3->alien[nodeid]) { alien = l3->alien[nodeid]; - spin_lock(&alien->lock); + spin_lock_nested(&alien->lock, nesting); if (unlikely(alien->avail == alien->limit)) { STATS_INC_ACOVERFLOW(cachep); __drain_alien_cache(cachep, alien, nodeid); @@ -1068,7 +1069,8 @@ static inline void free_alien_cache(struct array_cache **ac_ptr) { } -static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) +static inline int cache_free_alien(struct kmem_cache *cachep, void *objp, + int nesting) { return 0; } @@ -1272,6 +1274,11 @@ static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list, local_irq_disable(); memcpy(ptr, list, sizeof(struct kmem_list3)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->list_lock); + MAKE_ALL_LISTS(cachep, ptr, nodeid); cachep->nodelists[nodeid] = ptr; local_irq_enable(); @@ -1398,7 +1405,7 @@ void __init kmem_cache_init(void) } /* 4) Replace the bootstrap head arrays */ { - void *ptr; + struct array_cache *ptr; ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); @@ -1406,6 +1413,11 @@ void __init kmem_cache_init(void) BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); memcpy(ptr, cpu_cache_get(&cache_cache), sizeof(struct arraycache_init)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->lock); + cache_cache.array[smp_processor_id()] = ptr; local_irq_enable(); @@ -1416,6 +1428,11 @@ void __init kmem_cache_init(void) != &initarray_generic.cache); memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), sizeof(struct arraycache_init)); + /* + * Do not assume that spinlocks can be initialized via memcpy: + */ + spin_lock_init(&ptr->lock); + malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = ptr; local_irq_enable(); @@ -1743,6 +1760,8 @@ static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp) } #endif +static void __cache_free(struct kmem_cache *cachep, void *objp, int nesting); + /** * slab_destroy - destroy and release all objects in a slab * @cachep: cache pointer being destroyed @@ -1766,8 +1785,17 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) call_rcu(&slab_rcu->head, kmem_rcu_free); } else { kmem_freepages(cachep, addr); - if (OFF_SLAB(cachep)) - kmem_cache_free(cachep->slabp_cache, slabp); + if (OFF_SLAB(cachep)) { + unsigned long flags; + + /* + * lockdep: we may nest inside an already held + * ac->lock, so pass in a nesting flag: + */ + local_irq_save(flags); + __cache_free(cachep->slabp_cache, slabp, 1); + local_irq_restore(flags); + } } } @@ -3072,7 +3100,16 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, if (slabp->inuse == 0) { if (l3->free_objects > l3->free_limit) { l3->free_objects -= cachep->num; + /* + * It is safe to drop the lock. The slab is + * no longer linked to the cache. cachep + * cannot disappear - we are using it and + * all destruction of caches must be + * serialized properly by the user. + */ + spin_unlock(&l3->list_lock); slab_destroy(cachep, slabp); + spin_lock(&l3->list_lock); } else { list_add(&slabp->list, &l3->slabs_free); } @@ -3098,7 +3135,7 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) #endif check_irq_off(); l3 = cachep->nodelists[node]; - spin_lock(&l3->list_lock); + spin_lock_nested(&l3->list_lock, SINGLE_DEPTH_NESTING); if (l3->shared) { struct array_cache *shared_array = l3->shared; int max = shared_array->limit - shared_array->avail; @@ -3141,14 +3178,14 @@ free_done: * Release an obj back to its cache. If the obj has a constructed state, it must * be in this state _before_ it is released. Called with disabled ints. */ -static inline void __cache_free(struct kmem_cache *cachep, void *objp) +static void __cache_free(struct kmem_cache *cachep, void *objp, int nesting) { struct array_cache *ac = cpu_cache_get(cachep); check_irq_off(); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); - if (cache_free_alien(cachep, objp)) + if (cache_free_alien(cachep, objp, nesting)) return; if (likely(ac->avail < ac->limit)) { @@ -3387,7 +3424,7 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp) BUG_ON(virt_to_cache(objp) != cachep); local_irq_save(flags); - __cache_free(cachep, objp); + __cache_free(cachep, objp, 0); local_irq_restore(flags); } EXPORT_SYMBOL(kmem_cache_free); @@ -3412,7 +3449,7 @@ void kfree(const void *objp) kfree_debugcheck(objp); c = virt_to_cache(objp); debug_check_no_locks_freed(objp, obj_size(c)); - __cache_free(c, (void *)objp); + __cache_free(c, (void *)objp, 0); local_irq_restore(flags); } EXPORT_SYMBOL(kfree); |