[dpdk-dev] [PATCH v13 02/19] bus/pci: fix PCI address compare

[Burakov, Anatoly]

On 12-Jul-18 2:14 AM, Qi Zhang wrote:
> When use memcmp to compare two PCI address, sizeof(struct rte_pci_addr)
> is 4 bytes aligned, and it is 8. While only 7 byte of struct rte_pci_addr
> is valid. So compare the 8th byte will cause the unexpected result, which
> happens when repeatedly attach/detach a device.
> 
> Fixes: c752998b5e2e ("pci: introduce library and driver")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> ---
>   drivers/bus/pci/linux/pci_vfio.c | 13 ++++++++++++-
>   1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
> index aeeaa9ed8..dd25c3542 100644
> --- a/drivers/bus/pci/linux/pci_vfio.c
> +++ b/drivers/bus/pci/linux/pci_vfio.c
> @@ -43,6 +43,17 @@ static struct rte_tailq_elem rte_vfio_tailq = {
>   };
>   EAL_REGISTER_TAILQ(rte_vfio_tailq)
>   
> +/* Compair two pci address */
> +static int pci_addr_cmp(struct rte_pci_addr *addr1, struct rte_pci_addr *addr2)
> +{
> +	if (addr1->domain == addr2->domain &&
> +		addr1->bus == addr2->bus &&
> +		addr1->devid == addr2->devid &&
> +		addr1->function == addr2->function)
> +		return 0;
> +	return 1;
> +}

Generally, change looks OK to me, but I think we already have this 
function in PCI library - rte_pci_addr_cmp(). Is there a specific reason 
to reimplement it here?

> +
>   int
>   pci_vfio_read_config(const struct rte_intr_handle *intr_handle,
>   		    void *buf, size_t len, off_t offs)
> @@ -642,7 +653,7 @@ pci_vfio_unmap_resource(struct rte_pci_device *dev)
>   	vfio_res_list = RTE_TAILQ_CAST(rte_vfio_tailq.head, mapped_pci_res_list);
>   	/* Get vfio_res */
>   	TAILQ_FOREACH(vfio_res, vfio_res_list, next) {
> -		if (memcmp(&vfio_res->pci_addr, &dev->addr, sizeof(dev->addr)))
> +		if (pci_addr_cmp(&vfio_res->pci_addr, &dev->addr))
>   			continue;
>   		break;
>   	}
> 


-- 
Thanks,
Anatoly