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

Ajit Khaparde ajit.khaparde at broadcom.com
Thu Sep 10 00:05:01 CEST 2020


On Tue, Sep 8, 2020 at 3:07 AM Ferruh Yigit <ferruh.yigit at intel.com> wrote:

> '__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 at mellanox.com>
> Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
>
Tested-by: Ajit Khaparde <ajit.khaparde at broadcom.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
>
>


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