[PATCH 1/2] mem: zero out memory on free

[PATCH 1/2] mem: zero out memory on free

[Sergio Gonzalez Monroy]

Since [1] memzones are not guaranteed to be zeroed out.
This could potentially cause issues as applications might have been
relying on the allocated memory being zeroed out.

On init all allocated memory is zeroed by the kernel, so by zeroing out
memory on free, all available dpdk memory is always zeroed.

[1] fafcc11985a2 ("mem: rework memzone to be allocated by malloc")

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---
 lib/librte_eal/common/malloc_elem.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/librte_eal/common/malloc_elem.c b/lib/librte_eal/common/malloc_elem.c
index 27e9925..42568e1 100644
--- a/lib/librte_eal/common/malloc_elem.c
+++ b/lib/librte_eal/common/malloc_elem.c
@@ -275,11 +275,14 @@ malloc_elem_free(struct malloc_elem *elem)
 		return -1;
 
 	rte_spinlock_lock(&(elem->heap->lock));
+	size_t sz = elem->size - sizeof(*elem);
+	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);
 	}
 
 	/* check if previous element is free, if so join with it and return,
@@ -288,15 +291,17 @@ 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);
-		malloc_elem_free_list_insert(elem->prev);
-	}
-	/* otherwise add ourselves to the free list */
-	else {
-		malloc_elem_free_list_insert(elem);
-		elem->pad = 0;
+		sz += sizeof(*elem);
+		ptr -= sizeof(*elem);
+		elem = elem->prev;
 	}
+	malloc_elem_free_list_insert(elem);
+
 	/* decrease heap's count of allocated elements */
 	elem->heap->alloc_count--;
+
+	memset(ptr, 0, sz);
+
 	rte_spinlock_unlock(&(elem->heap->lock));
 
 	return 0;
-- 
2.4.11

[PATCH 2/2] malloc: no need to zero out memory on zmalloc

[Sergio Gonzalez Monroy]

Zeroing out memory on rte_zmalloc_socket is not required anymore since all
allocated memory is already zeroed.

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---
 lib/librte_eal/common/rte_malloc.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/lib/librte_eal/common/rte_malloc.c b/lib/librte_eal/common/rte_malloc.c
index 47deb00..f4a8835 100644
--- a/lib/librte_eal/common/rte_malloc.c
+++ b/lib/librte_eal/common/rte_malloc.c
@@ -123,11 +123,7 @@ rte_malloc(const char *type, size_t size, unsigned align)
 void *
 rte_zmalloc_socket(const char *type, size_t size, unsigned align, int socket)
 {
-	void *ptr = rte_malloc_socket(type, size, align, socket);
-
-	if (ptr != NULL)
-		memset(ptr, 0, size);
-	return ptr;
+	return rte_malloc_socket(type, size, align, socket);
 }
 
 /*
-- 
2.4.11

Re: [PATCH 2/2] malloc: no need to zero out memory on zmalloc

[Thomas Monjalon]

2016-07-05 12:01, Sergio Gonzalez Monroy:
> Zeroing out memory on rte_zmalloc_socket is not required anymore since all
> allocated memory is already zeroed.
> 
> Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>

Series applied, thanks

This patch will need special attention when validating this release.