RE: [PATCH v4] eal: fix uncheck lcore ID and lcore role

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Dengdui Huang [mailto:huangdengdui@huawei.com]
> Sent: Thursday, 24 July 2025 13.26
> 
> The worker_id may come from user input. So it is necessary to verify it.
> 
> In addition, only the lcore whose role is ROLE_RTE or ROLE_SERVICE can
> be
> launched. This patch adds the lcore role check.
> 
> Fixes: a95d70547c57 ("eal: factorize lcore main loop")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Dengdui Huang <huangdengdui@huawei.com>
> ---
>  lib/eal/common/eal_common_launch.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/lib/eal/common/eal_common_launch.c
> b/lib/eal/common/eal_common_launch.c
> index a7deac6ecd..09366ea404 100644
> --- a/lib/eal/common/eal_common_launch.c
> +++ b/lib/eal/common/eal_common_launch.c
> @@ -20,6 +20,9 @@ RTE_EXPORT_SYMBOL(rte_eal_wait_lcore)
>  int
>  rte_eal_wait_lcore(unsigned worker_id)
>  {
> +	if (unlikely(worker_id >= RTE_MAX_LCORE))
> +		return -EINVAL;
> +
>  	while (rte_atomic_load_explicit(&lcore_config[worker_id].state,
>  			rte_memory_order_acquire) != WAIT)
>  		rte_pause();
> @@ -37,6 +40,18 @@ int
>  rte_eal_remote_launch(lcore_function_t *f, void *arg, unsigned int
> worker_id)
>  {
>  	int rc = -EBUSY;
> +	uint8_t role;

Use the correct type:
enum rte_lcore_role_t role;

> +
> +	if (unlikely(worker_id >= RTE_MAX_LCORE)) {
> +		rc = -EINVAL;
> +		goto finish;
> +	}
> +
> +	role = lcore_config[worker_id].core_role;
> +	if (role != ROLE_RTE && role != ROLE_SERVICE) {
> +		rc = -EINVAL;
> +		goto finish;
> +	}
> 
>  	/* Check if the worker is in 'WAIT' state. Use acquire order
>  	 * since 'state' variable is used as the guard variable.
> @@ -98,6 +113,9 @@ RTE_EXPORT_SYMBOL(rte_eal_get_lcore_state)
>  enum rte_lcore_state_t
>  rte_eal_get_lcore_state(unsigned lcore_id)
>  {
> +	if (unlikely(lcore_id >= RTE_MAX_LCORE))
> +		return -EINVAL;

The return type of this function is enum rte_lcore_state_t, so it cannot return (int)-EINVAL.

Maybe it's better to update the function's documentation instead of its implementation.
Like the documentation of the lcore_id parameter passed to rte_eal_lcore_role():
https://elixir.bootlin.com/dpdk/v25.07/source/lib/eal/include/rte_lcore.h#L44

After further consideration, updating the documentation might also be a better solution for the other functions.

If you add a new return value (-EINVAL) to a function, it must be listed in function's documentation, and in the documentation of functions calling that function.

> +
>  	return lcore_config[lcore_id].state;
>  }
> 
> --
> 2.33.0