[dpdk-dev] [PATCH v3 2/2] eal/malloc: fix RTE malloc element free

Xueming Li xuemingl at mellanox.com
Sat Sep 9 09:33:19 CEST 2017


malloc_elem_free() is clearing(setting to 0) the trailer cookie when
RTE_MALLOC_DEBUG is enabled. In case of joining free neighbor element,
part of joined memory is not getting cleared due to missing the length
of trailer cookie in the middle.

This patch fixes calculation of free memory length to be cleared in
malloc_elem_free() by including trailer cookie.

Fixes: af75078fece3 ("first public release")

Cc: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>
Signed-off-by: Xueming Li <xuemingl at mellanox.com>
---
 lib/librte_eal/common/malloc_elem.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/common/malloc_elem.c b/lib/librte_eal/common/malloc_elem.c
index 150769057..889dffd21 100644
--- a/lib/librte_eal/common/malloc_elem.c
+++ b/lib/librte_eal/common/malloc_elem.c
@@ -275,14 +275,14 @@ malloc_elem_free(struct malloc_elem *elem)
 		return -1;
 
 	rte_spinlock_lock(&(elem->heap->lock));
-	size_t sz = elem->size - sizeof(*elem);
+	size_t sz = elem->size - sizeof(*elem) - MALLOC_ELEM_TRAILER_LEN;
 	uint8_t *ptr = (uint8_t *)&elem[1];
 	struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
 	if (next->state == ELEM_FREE){
 		/* remove from free list, join to this one */
 		elem_free_list_remove(next);
 		join_elem(elem, next);
-		sz += sizeof(*elem);
+		sz += (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
 	}
 
 	/* check if previous element is free, if so join with it and return,
@@ -291,8 +291,8 @@ malloc_elem_free(struct malloc_elem *elem)
 	if (elem->prev != NULL && elem->prev->state == ELEM_FREE) {
 		elem_free_list_remove(elem->prev);
 		join_elem(elem->prev, elem);
-		sz += sizeof(*elem);
-		ptr -= sizeof(*elem);
+		sz += (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
+		ptr -= (sizeof(*elem) + MALLOC_ELEM_TRAILER_LEN);
 		elem = elem->prev;
 	}
 	malloc_elem_free_list_insert(elem);
-- 
2.13.3



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