Re: [dpdk-dev] [PATCH] pci: remove unnecessary access() check

[David Marchand <david.marchand@redhat.com>]

On Tue, Aug 13, 2019 at 5:38 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
>
> Just open the sysfs file and handle failure, rather than
> using access(). This eliminates Coverity warnings about
> "time of check versus time of use"; although for this sysfs
> file that is not really an issue anyway.
>
> Coverity ID: 347276
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

Title prefix should be "bus/pci: " (check-git-log.sh).


> ---
>  drivers/bus/pci/linux/pci.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
> index 43debaa25114..6c444aa7ae3d 100644
> --- a/drivers/bus/pci/linux/pci.c
> +++ b/drivers/bus/pci/linux/pci.c
> @@ -512,18 +512,19 @@ pci_device_iommu_support_va(const struct rte_pci_device *dev)
>                  "%s/" PCI_PRI_FMT "/iommu/intel-iommu/cap",
>                  rte_pci_get_sysfs_path(), addr->domain, addr->bus, addr->devid,
>                  addr->function);
> -       if (access(filename, F_OK) == -1) {
> -               /* We don't have an Intel IOMMU, assume VA supported*/
> -               return true;
> -       }
>
> -       /* We have an intel IOMMU */
>         fp = fopen(filename, "r");
>         if (fp == NULL) {
> -               RTE_LOG(ERR, EAL, "%s(): can't open %s\n", __func__, filename);
> +               /* We don't have an Intel IOMMU, assume VA supported*/

Nit: missing a space before closing the comment.

> +               if (errno == ENOENT)
> +                       return true;
> +
> +               RTE_LOG(ERR, EAL, "%s(): can't open %s: %s\n",
> +                       __func__, filename, strerror(errno));
>                 return false;
>         }
>
> +       /* We have an intel IOMMU */
>         if (fscanf(fp, "%" PRIx64, &vtd_cap_reg) != 1) {
>                 RTE_LOG(ERR, EAL, "%s(): can't read %s\n", __func__, filename);
>                 fclose(fp);
> --
> 2.20.1
>

Reviewed-by: David Marchand <david.marchand@redhat.com>


-- 
David Marchand