diff options
Diffstat (limited to 'mm/mempool.c')
| -rw-r--r-- | mm/mempool.c | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/mm/mempool.c b/mm/mempool.c index 204a216b6418..1c38e873e546 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -136,7 +136,7 @@ static void kasan_unpoison_element(mempool_t *pool, void *element) static __always_inline void add_element(mempool_t *pool, void *element) { - BUG_ON(pool->curr_nr >= pool->min_nr); + BUG_ON(pool->min_nr != 0 && pool->curr_nr >= pool->min_nr); poison_element(pool, element); if (kasan_poison_element(pool, element)) pool->elements[pool->curr_nr++] = element; @@ -202,16 +202,20 @@ int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn, pool->alloc = alloc_fn; pool->free = free_fn; init_waitqueue_head(&pool->wait); - - pool->elements = kmalloc_array_node(min_nr, sizeof(void *), + /* + * max() used here to ensure storage for at least 1 element to support + * zero minimum pool + */ + pool->elements = kmalloc_array_node(max(1, min_nr), sizeof(void *), gfp_mask, node_id); if (!pool->elements) return -ENOMEM; /* - * First pre-allocate the guaranteed number of buffers. + * First pre-allocate the guaranteed number of buffers, + * also pre-allocate 1 element for zero minimum pool. */ - while (pool->curr_nr < pool->min_nr) { + while (pool->curr_nr < max(1, pool->min_nr)) { void *element; element = pool->alloc(gfp_mask, pool->pool_data); @@ -555,20 +559,12 @@ void mempool_free(void *element, mempool_t *pool) * wake-up path of previous test. This explicit check ensures the * allocation of element when both min_nr and curr_nr are 0, and * any active waiters are properly awakened. - * - * Inline the same logic as previous test, add_element() cannot be - * directly used here since it has BUG_ON to deny if min_nr equals - * curr_nr, so here picked rest of add_element() to use without - * BUG_ON check. */ if (unlikely(pool->min_nr == 0 && READ_ONCE(pool->curr_nr) == 0)) { spin_lock_irqsave(&pool->lock, flags); if (likely(pool->curr_nr == 0)) { - /* Inline the logic of add_element() */ - poison_element(pool, element); - if (kasan_poison_element(pool, element)) - pool->elements[pool->curr_nr++] = element; + add_element(pool, element); spin_unlock_irqrestore(&pool->lock, flags); if (wq_has_sleeper(&pool->wait)) wake_up(&pool->wait); |