[PATCH v2] aesni_mb: strict-aliasing rule compilation fix

[Declan Doherty <declan.doherty@intel.com>]

Fixes: 924e84f87306 ("aesni_mb: add driver for multi buffer based crypto")

When compiling the AESNI_MB PMD with GCC 4.4.7 on Centos 6.7 a "dereferencing
pointer ‘obj_p’ does break strict-aliasing rules" warning occurs in the
get_session() function.

Signed-off-by: Declan Doherty <declan.doherty@intel.com>
---
Adding "Fixes" details to patch

 drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
index d8ccf05..18ce176 100644
--- a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
+++ b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
@@ -299,7 +299,7 @@ aesni_mb_set_session_parameters(const struct aesni_mb_ops *mb_ops,
 static struct aesni_mb_session *
 get_session(struct aesni_mb_qp *qp, struct rte_crypto_op *crypto_op)
 {
-	struct aesni_mb_session *sess;
+	struct aesni_mb_session *sess = NULL;
 
 	if (crypto_op->type == RTE_CRYPTO_OP_WITH_SESSION) {
 		if (unlikely(crypto_op->session->type !=
@@ -308,16 +308,19 @@ get_session(struct aesni_mb_qp *qp, struct rte_crypto_op *crypto_op)
 
 		sess = (struct aesni_mb_session *)crypto_op->session->_private;
 	} else  {
-		struct rte_cryptodev_session *c_sess = NULL;
+		void *_sess = NULL;
 
-		if (rte_mempool_get(qp->sess_mp, (void **)&c_sess))
+		if (rte_mempool_get(qp->sess_mp, (void **)&_sess))
 			return NULL;
 
-		sess = (struct aesni_mb_session *)c_sess->_private;
+		sess = (struct aesni_mb_session *)
+			((struct rte_cryptodev_session *)_sess)->_private;
 
 		if (unlikely(aesni_mb_set_session_parameters(qp->ops,
-				sess, crypto_op->xform) != 0))
-			return NULL;
+				sess, crypto_op->xform) != 0)) {
+			rte_mempool_put(qp->sess_mp, _sess);
+			sess = NULL;
+		}
 	}
 
 	return sess;
-- 
2.5.0