[dpdk-dev] [PATCH] net/netvsc: replace compiler builtin overflow check

[Ferruh Yigit <ferruh.yigit@intel.com>]

'__builtin_add_overflow' added to gcc in version 5, earlier versions
causing build error, like gcc 4.8.5 in RHEL7.

Replaced compiler builtin check with arithmetic check.

Fixes: cabb3c0f29f1 ("net/netvsc: check for overflow on packet info from host")

Reported-by: Raslan Darawsheh <rasland@mellanox.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 drivers/net/netvsc/hn_rxtx.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index d8d3f07f56..3e8d3b407d 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -666,7 +666,7 @@ static void hn_rndis_rx_data(struct hn_rx_queue *rxq,
 			     struct hn_rx_bufinfo *rxb,
 			     void *data, uint32_t dlen)
 {
-	unsigned int data_off, data_len, total_len;
+	unsigned int data_off, data_len;
 	unsigned int pktinfo_off, pktinfo_len;
 	const struct rndis_packet_msg *pkt = data;
 	struct hn_rxinfo info = {
@@ -712,8 +712,8 @@ static void hn_rndis_rx_data(struct hn_rx_queue *rxq,
 			goto error;
 	}
 
-	if (__builtin_add_overflow(data_off, data_len, &total_len) ||
-	    total_len > pkt->len)
+	/* overflow check */
+	if (data_len > data_len + data_off || data_len + data_off > pkt->len)
 		goto error;
 
 	if (unlikely(data_len < RTE_ETHER_HDR_LEN))
-- 
2.25.4