Re: [dpdk-dev] [PATCH] bpf: fix to allow ptr stack program type

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

Hi Jerin,

> 
> bpf_validate does not allow to execute
> RTE_BPF_ARG_PTR_STACK for no reason.

I believe there is a reason,
ARG_PTR_STACK is reserved for memory within BPF program internal stack only.
User that calls BPF program should never pass parameter with that type.
If the user allocates parameter for bpf function on the stack, he can
still use RTE_BPF_ARG_PTR for it.
Konstantin

> Fix it by enhancing the prog_arg.type check.
> 
> Fixes: 6e12ec4c4d6d ("bpf: add more checks")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Jerin Jacob <jerinj@marvell.com>
> ---
>  lib/librte_bpf/bpf_validate.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/librte_bpf/bpf_validate.c b/lib/librte_bpf/bpf_validate.c
> index 0cf41fa27..c75777b6d 100644
> --- a/lib/librte_bpf/bpf_validate.c
> +++ b/lib/librte_bpf/bpf_validate.c
> @@ -2216,6 +2216,7 @@ bpf_validate(struct rte_bpf *bpf)
> 
>  	/* check input argument type, don't allow mbuf ptr on 32-bit */
>  	if (bpf->prm.prog_arg.type != RTE_BPF_ARG_RAW &&
> +			bpf->prm.prog_arg.type != RTE_BPF_ARG_PTR_STACK &&
>  			bpf->prm.prog_arg.type != RTE_BPF_ARG_PTR &&
>  			(sizeof(uint64_t) != sizeof(uintptr_t) ||
>  			bpf->prm.prog_arg.type != RTE_BPF_ARG_PTR_MBUF)) {
> --
> 2.22.0