[PATCH dpdk] mbuf: fix strict aliasing error in allocator

[Robin Jarry]

When building an application with -fstrict-aliasing -Wstrict-aliasing=2,
we get errors triggered by rte_mbuf_raw_alloc() which is called inline
from rte_pktmbuf_alloc().

 ../dpdk/lib/mbuf/rte_mbuf.h: In function ‘rte_mbuf_raw_alloc’:
 ../dpdk/lib/mbuf/rte_mbuf.h:600:42: error: dereferencing type-punned
 pointer might break strict-aliasing rules [-Werror=strict-aliasing]
   600 |         if (rte_mempool_get(mp, (void **)&m) < 0)
       |                                          ^~

Avoid incorrect casting by changing the type of the returned variable.

Signed-off-by: Robin Jarry <rja...@redhat.com>
---
 lib/mbuf/rte_mbuf.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/mbuf/rte_mbuf.h b/lib/mbuf/rte_mbuf.h
index babe16c72ccb..bab1fb94d41d 100644
--- a/lib/mbuf/rte_mbuf.h
+++ b/lib/mbuf/rte_mbuf.h
@@ -595,9 +595,9 @@ __rte_mbuf_raw_sanity_check(__rte_unused const struct 
rte_mbuf *m)
  */
 static inline struct rte_mbuf *rte_mbuf_raw_alloc(struct rte_mempool *mp)
 {
-       struct rte_mbuf *m;
+       void *m;
 
-       if (rte_mempool_get(mp, (void **)&m) < 0)
+       if (rte_mempool_get(mp, &m) < 0)
                return NULL;
        __rte_mbuf_raw_sanity_check(m);
        return m;
-- 
2.46.1