Hi
> -----Original Message-----
> From: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
> Sent: Friday, July 2, 2021 10:23 PM
> To: Matan Azrad <ma...@nvidia.com>; Shahaf Shuler <shah...@nvidia.com>; Slava
> Ovsiienko <viachesl...@nvidia.com>; NBU-
> Contact-Thomas Monjalon <tho...@monjalon.net>; Ferruh Yigit
> <ferruh.yi...@intel.com>; Xueming(Steven) Li
> <xuemi...@nvidia.com>
> Cc: dev@dpdk.org; Viacheslav Galaktionov
> <viacheslav.galaktio...@oktetlabs.ru>; sta...@dpdk.org
> Subject: [PATCH] ethdev: keep count of allocated and used representor ranges
>
> From: Viacheslav Galaktionov <viacheslav.galaktio...@oktetlabs.ru>
>
> In its current state, the API can overflow the user-passed buffer if a new
> representor range appears between function calls.
>
> In order to solve this problem, augment the representor info structure with
> the numbers of allocated and initialized ranges. This way
> the users of this structure can be sure they will not overrun the buffer.
Thanks for making this api more robust!
>
> Fixes: 85e1588ca72f ("ethdev: add API to get representor info")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Viacheslav Galaktionov <viacheslav.galaktio...@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
> ---
> drivers/net/mlx5/mlx5_ethdev.c | 15 +++++++++++++++
> lib/ethdev/rte_ethdev.c | 6 ++++--
> lib/ethdev/rte_ethdev.h | 9 ++++++++-
> 3 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
> index 90baee5aa4..61b1c0e75c 100644
> --- a/drivers/net/mlx5/mlx5_ethdev.c
> +++ b/drivers/net/mlx5/mlx5_ethdev.c
> @@ -413,9 +413,15 @@ mlx5_representor_info_get(struct rte_eth_dev *dev,
> int n_type = 4; /* Representor types, VF, HPF@VF, SF and HPF@SF. */
> int n_pf = 2; /* Number of PFs. */
> int i = 0, pf;
> + int n_entries;
>
> if (info == NULL)
> goto out;
> +
> + n_entries = n_type * n_pf;
> + if ((uint32_t)n_entries > info->nb_ranges_alloc)
> + n_entries = info->nb_ranges_alloc;
> +
> info->controller = 0;
> info->pf = priv->pf_bond >= 0 ? priv->pf_bond : 0;
> for (pf = 0; pf < n_pf; ++pf) {
> @@ -431,6 +437,8 @@ mlx5_representor_info_get(struct rte_eth_dev *dev,
> snprintf(info->ranges[i].name,
> sizeof(info->ranges[i].name), "pf%dvf", pf);
> i++;
> + if (i == n_entries)
> + break;
> /* HPF range of VF type. */
> info->ranges[i].type = RTE_ETH_REPRESENTOR_VF;
> info->ranges[i].controller = 0;
> @@ -443,6 +451,8 @@ mlx5_representor_info_get(struct rte_eth_dev *dev,
> snprintf(info->ranges[i].name,
> sizeof(info->ranges[i].name), "pf%dvf", pf);
> i++;
> + if (i == n_entries)
> + break;
> /* SF range. */
> info->ranges[i].type = RTE_ETH_REPRESENTOR_SF;
> info->ranges[i].controller = 0;
> @@ -455,6 +465,8 @@ mlx5_representor_info_get(struct rte_eth_dev *dev,
> snprintf(info->ranges[i].name,
> sizeof(info->ranges[i].name), "pf%dsf", pf);
> i++;
> + if (i == n_entries)
> + break;
> /* HPF range of SF type. */
> info->ranges[i].type = RTE_ETH_REPRESENTOR_SF;
> info->ranges[i].controller = 0;
> @@ -467,8 +479,11 @@ mlx5_representor_info_get(struct rte_eth_dev *dev,
> snprintf(info->ranges[i].name,
> sizeof(info->ranges[i].name), "pf%dsf", pf);
> i++;
> + if (i == n_entries)
> + break;
> }
> out:
> + info->nb_ranges = i;
Here info maybe NULL.
> return n_type * n_pf;
> }
>
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c index
> c607eabb5b..30abc93b18 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -5987,7 +5987,8 @@ rte_eth_representor_id_get(const struct rte_eth_dev
> *ethdev,
> int controller, int pf, int representor_port,
> uint16_t *repr_id)
> {
> - int ret, n, i, count;
> + int ret, n, count;
> + uint32_t i;
> struct rte_eth_representor_info *info = NULL;
> size_t size;
>
> @@ -6011,6 +6012,7 @@ rte_eth_representor_id_get(const struct rte_eth_dev
> *ethdev,
> info = calloc(1, size);
> if (info == NULL)
> return -ENOMEM;
> + info->nb_ranges_alloc = n;
> ret = rte_eth_representor_info_get(ethdev->data->port_id, info);
> if (ret < 0)
> goto out;
> @@ -6023,7 +6025,7 @@ rte_eth_representor_id_get(const struct rte_eth_dev
> *ethdev,
>
> /* Locate representor ID. */
> ret = -ENOENT;
> - for (i = 0; i < n; ++i) {
> + for (i = 0; i < info->nb_ranges; ++i) {
> if (info->ranges[i].type != type)
> continue;
> if (info->ranges[i].controller != controller) diff --git
> a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index
> faf3bd901d..d2b27c351f 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -4856,6 +4856,8 @@ struct rte_eth_representor_range { struct
> rte_eth_representor_info {
> uint16_t controller; /**< Controller ID of caller device. */
> uint16_t pf; /**< Physical function ID of caller device. */
> + uint32_t nb_ranges_alloc; /**< Size of the ranges array. */
> + uint32_t nb_ranges; /**< Number of initialized ranges. */
How about rte_eth_representor_info_get(info) return max ranges size if info is
NULL,
return real initialized ranges if info not NULL?
> struct rte_eth_representor_range ranges[];/**< Representor ID range. */
> };
>
> @@ -4871,11 +4873,16 @@ struct rte_eth_representor_info {
> * A pointer to a representor info structure.
> * NULL to return number of range entries and allocate memory
> * for next call to store detail.
> + * The number of ranges that were written into this structure
> + * will be placed into its nb_ranges field. This number cannot be
> + * larger than the nb_ranges_alloc that by the user before calling
> + * this function. It can be smaller than the value returned by the
> + * function, however.
> * @return
> * - (-ENOTSUP) if operation is not supported.
> * - (-ENODEV) if *port_id* invalid.
> * - (-EIO) if device is removed.
> - * - (>=0) number of representor range entries supported by device.
> + * - (>=0) number of available representor range entries.
> */
> __rte_experimental
> int rte_eth_representor_info_get(uint16_t port_id,
> --
> 2.30.2
