smalloc: just round alloc_size to int aligned for post redzone pointer
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/smalloc.c b/smalloc.c
index e0bc498..ac5754d 100644
--- a/smalloc.c
+++ b/smalloc.c
@@ -27,6 +27,7 @@
#define SMALLOC_POST_RED 0x5aa55aa5U
unsigned int smalloc_pool_size = INITIAL_SIZE;
+const int int_mask = sizeof(int) - 1;
struct pool {
struct fio_mutex *lock; /* protects this pool */
@@ -270,7 +271,6 @@
#ifdef SMALLOC_REDZONE
static void *postred_ptr(struct block_hdr *hdr)
{
- const int int_mask = sizeof(unsigned int) - 1;
unsigned long ptr;
ptr = (unsigned long) hdr + hdr->size - sizeof(unsigned int);
@@ -426,11 +426,12 @@
void *ptr;
/*
- * Use twice the size for good luck, we may need to adjust
- * alignment.
+ * Round to int alignment, so that the postred pointer will
+ * be naturally aligned as well.
*/
#ifdef SMALLOC_REDZONE
- alloc_size += 2 * sizeof(unsigned int);
+ alloc_size += sizeof(unsigned int);
+ alloc_size = (alloc_size + int_mask) & ~int_mask;
#endif
ptr = __smalloc_pool(pool, alloc_size);