[PATCH] mm: remove broken 'kzalloc' mempool

From: Sage Weil
Date: Mon Aug 03 2009 - 16:55:19 EST


The kzalloc mempool zeros items when they are initially allocated, but
does not rezero used items that are returned to the pool. Consequently
mempool_alloc()s may return non-zeroed memory.

Since there are/were only two in-tree users for mempool_create_kzalloc_pool(),
and 'fixing' this in a way that will re-zero used (but not new) items
before first use is non-trivial, just remove it.

CC: <linux-mm@xxxxxxxxx>
Signed-off-by: Sage Weil <sage@xxxxxxxxxxxx>
---
include/linux/mempool.h | 10 ++--------
mm/mempool.c | 7 -------
2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/include/linux/mempool.h b/include/linux/mempool.h
index 9be484d..7c08052 100644
--- a/include/linux/mempool.h
+++ b/include/linux/mempool.h
@@ -47,22 +47,16 @@ mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
}

/*
- * 2 mempool_alloc_t's and a mempool_free_t to kmalloc/kzalloc and kfree
- * the amount of memory specified by pool_data
+ * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
+ * amount of memory specified by pool_data
*/
void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
-void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data);
void mempool_kfree(void *element, void *pool_data);
static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
{
return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
(void *) size);
}
-static inline mempool_t *mempool_create_kzalloc_pool(int min_nr, size_t size)
-{
- return mempool_create(min_nr, mempool_kzalloc, mempool_kfree,
- (void *) size);
-}

/*
* A mempool_alloc_t and mempool_free_t for a simple page allocator that
diff --git a/mm/mempool.c b/mm/mempool.c
index a46eb1b..eea4f7d 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -308,13 +308,6 @@ void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
}
EXPORT_SYMBOL(mempool_kmalloc);

-void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data)
-{
- size_t size = (size_t) pool_data;
- return kzalloc(size, gfp_mask);
-}
-EXPORT_SYMBOL(mempool_kzalloc);
-
void mempool_kfree(void *element, void *pool_data)
{
kfree(element);
--
1.5.6.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/