Re: [PATCH] Signed-off-by: giladreti <gilad.reti@xxxxxxxxx>

[Daniel Borkmann]

Hello Gilad,

On 1/11/21 4:31 PM, giladreti wrote:
> Added support for pointer to mem register spilling, to allow the verifier
> to track pointer to valid memory addresses. Such pointers are returned
> for example by a successful call of the bpf_ringbuf_reserve helper.
>
> This patch was suggested as a solution by Yonghong Song.

The SoB should not be in subject line but as part of the commit message instead
and with proper name, e.g.

Signed-off-by: Gilad Reti <gilad.reti@xxxxxxxxx>

For subject line, please use a short summary that fits the patch prefixed with
the subsystem "bpf: [...]", see also [0] as an example. Thanks.

It would be good if you could also add a BPF selftest for this [1].

  [0] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=e22d7f05e445165e58feddb4e40cc9c0f94453bc
  [1] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/testing/selftests/bpf/
      https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/testing/selftests/bpf/verifier/spill_fill.c

> ---
>   kernel/bpf/verifier.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 17270b8404f1..36af69fac591 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -2217,6 +2217,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
>   	case PTR_TO_RDWR_BUF:
>   	case PTR_TO_RDWR_BUF_OR_NULL:
>   	case PTR_TO_PERCPU_BTF_ID:
> +	case PTR_TO_MEM:
> +	case PTR_TO_MEM_OR_NULL:
>   		return true;
>   	default:
>   		return false;