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From:   Gilad Reti <gilad.reti@gmail.com>
Date:   Mon, 11 Jan 2021 18:03:58 +0200
Message-ID: <CANaYP3FiB-+Zs3C27VgPW+4Ltg8b9dErYAoX7Gu2WqkczcC8vw@mail.gmail.com>
Subject: Re: [PATCH] Signed-off-by: giladreti <gilad.reti@gmail.com>
To:     Daniel Borkmann <daniel@iogearbox.net>
Cc:     bpf <bpf@vger.kernel.org>, Yonghong Song <yhs@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Networking <netdev@vger.kernel.org>, linux-kernel@vger.kernel.org
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On Mon, Jan 11, 2021, 17:55 Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> 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@gmail.com>
>
> 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
>

Sure. Thanks for your guidance. As you can probably tell, I am new to
kernel code contribution (in fact this is a first time for me).
Should I try to submit this patch again?

Sorry in advance for all the overhead I may be causing to you...

> > ---
> >   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;
> >
>