Re: [dpdk-stable] [dpdk-dev] [PATCH v4] ethdev: fix data type for port id

[Ajit Khaparde <ajit.khaparde@broadcom.com>]

On Tue, Nov 3, 2020 at 6:58 PM wangyunjian <wangyunjian@huawei.com> wrote:
>
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> The ethdev port id is 16 bits now. This patch fixes the data type
> of the variable for 'pid', which changing from uint32_t to uint16_t.
>
> RTE_MAX_ETHPORTS is the maximum number of ports, which customized by
> the user. To avoid 16-bit unsigned integer overflow, the valid value
> of RTE_MAX_ETHPORTS should be set from 0 to UINT16_MAX, and it is
> safer to cut one more port from space.
>
> So we use RTE_BUILD_BUG_ON() to ensure that RTE_MAX_ETHPORTS is less
> to UINT16_MAX.
>
> Fixes: 5b7ba31148a8 ("ethdev: add port ownership")
> Cc: stable@dpdk.org
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>

Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

> ---
> v4:
>    remove redundant compile checks
> v3:
>    fix code styles suggested by Thomas Monjalon and Andrew Rybchenko
> v2:
>    add RTE_BUILD_BUG_ON() check for RTE_MAX_ETHPORTS validity
> ---
>  lib/librte_ethdev/rte_ethdev.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index b12bb3854d..0af8e4d76c 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -411,7 +411,9 @@ eth_dev_is_allocated(const struct rte_eth_dev *ethdev)
>  static struct rte_eth_dev *
>  eth_dev_allocated(const char *name)
>  {
> -       unsigned i;
> +       uint16_t i;
> +
> +       RTE_BUILD_BUG_ON(RTE_MAX_ETHPORTS >= UINT16_MAX);
>
>         for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
>                 if (rte_eth_devices[i].data != NULL &&
> @@ -440,7 +442,7 @@ rte_eth_dev_allocated(const char *name)
>  static uint16_t
>  eth_dev_find_free_port(void)
>  {
> -       unsigned i;
> +       uint16_t i;
>
>         for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
>                 /* Using shared name field to find a free port. */
> @@ -816,7 +818,7 @@ rte_eth_dev_get_name_by_port(uint16_t port_id, char *name)
>  int
>  rte_eth_dev_get_port_by_name(const char *name, uint16_t *port_id)
>  {
> -       uint32_t pid;
> +       uint16_t pid;
>
>         if (name == NULL) {
>                 RTE_ETHDEV_LOG(ERR, "Null pointer is specified\n");
> @@ -4290,7 +4292,7 @@ rte_eth_mirror_rule_reset(uint16_t port_id, uint8_t rule_id)
>
>  RTE_INIT(eth_dev_init_cb_lists)
>  {
> -       int i;
> +       uint16_t i;
>
>         for (i = 0; i < RTE_MAX_ETHPORTS; i++)
>                 TAILQ_INIT(&rte_eth_devices[i].link_intr_cbs);
> @@ -4303,7 +4305,7 @@ rte_eth_dev_callback_register(uint16_t port_id,
>  {
>         struct rte_eth_dev *dev;
>         struct rte_eth_dev_callback *user_cb;
> -       uint32_t next_port; /* size is 32-bit to prevent loop wrap-around */
> +       uint16_t next_port;
>         uint16_t last_port;
>
>         if (!cb_fn)
> @@ -4366,7 +4368,7 @@ rte_eth_dev_callback_unregister(uint16_t port_id,
>         int ret;
>         struct rte_eth_dev *dev;
>         struct rte_eth_dev_callback *cb, *next;
> -       uint32_t next_port; /* size is 32-bit to prevent loop wrap-around */
> +       uint16_t next_port;
>         uint16_t last_port;
>
>         if (!cb_fn)
> @@ -5507,7 +5509,7 @@ static struct rte_eth_dev_switch {
>  int
>  rte_eth_switch_domain_alloc(uint16_t *domain_id)
>  {
> -       unsigned int i;
> +       uint16_t i;
>
>         *domain_id = RTE_ETH_DEV_SWITCH_DOMAIN_ID_INVALID;
>
> --
> 2.18.1
>