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ng_pktbuf: fix alignment overwrite issue

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Currently it can happen if there is a spot of size `n` free that a chunk
of size `n + 1` is inserted, if `n` is devisable by the word length of
the platform. This patch fixes this issue.
This commit is contained in:
Martine Lenders 2015-07-05 00:22:49 +02:00
parent 057ad18f22
commit 3b133811d6
1 changed files with 15 additions and 6 deletions
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21
sys/net/crosslayer/ng_pktbuf/_pktbuf_static.c
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@ -88,12 +88,10 @@ static inline size_t __total_sz(_used_t *node)
}
/**
* @brief aligned size with metadata
* @brief aligns @p size to the next word alignment.
*/
static inline size_t __al_total_sz(_used_t *node)
static inline size_t _al_sz(size_t size)
{
size_t size = __total_sz(node);
if (size % _PKTBUF_ALIGN_BYTES) {
return size + (_PKTBUF_ALIGN_BYTES - (size % _PKTBUF_ALIGN_BYTES));
}
@ -102,6 +100,14 @@ static inline size_t __al_total_sz(_used_t *node)
}
}
/**
* @brief aligned size with metadata
*/
static inline size_t __al_total_sz(_used_t *node)
{
return _al_sz(__total_sz(node));
}
/**
* @brief Index of an allocation's first byte in buffer
*/
@ -141,6 +147,9 @@ static _used_t *_find(_used_t **prev_ptr, _used_t **node_ptr, const void *ptr)
return NULL;
}
/**
* @brief Allocate chunk of @p size in _buf
*/
void *_pktbuf_internal_alloc(size_t size)
{
_used_t *node = _head(), *old_next, *new_next;
@ -163,9 +172,9 @@ void *_pktbuf_internal_alloc(size_t size)
}
}
while ((node->next != NULL)
while ((node->next != NULL) /* while not last chunk allocation */
/* and if space between current and next allocation is not big enough */
&& ((_start_idx(node->next) - _end_idx(node)) < _total_sz(size))) {
&& ((_start_idx(node->next) - _end_idx(node)) < _al_sz(_total_sz(size)))) {
node = node->next;
}