Re: [PATCH bpf 1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register spilling

[Gilad Reti <gilad.reti@gmail.com>]

On Tue, Jan 12, 2021 at 3:57 PM KP Singh <kpsingh@kernel.org> wrote:
>
> On Tue, Jan 12, 2021 at 10:14 AM Gilad Reti <gilad.reti@gmail.com> wrote:
> >
> > Add support for pointer to mem register spilling, to allow the verifier
> > to track pointer to valid memory addresses. Such pointers are returned
>
> nit: pointers

Thanks

>
> > for example by a successful call of the bpf_ringbuf_reserve helper.
> >
> > This patch was suggested as a solution by Yonghong Song.
>
> You can use the "Suggested-by:" tag for this.

Thanks

>
> >
> > The patch was partially contibuted by CyberArk Software, Inc.
>
> nit: typo *contributed

Thanks. Should I submit a v2 of the patch to correct all of those?

>
> Also, I was wondering if "partially" here means someone collaborated with you
> on the patch? And, in that case:
>
> "Co-developed-by:" would be a better tag here.

No, I did it alone. I mentioned CyberArk since I work there and did some of the
coding during my daily work, so they deserve credit.

>
> Acked-by: KP Singh <kpsingh@kernel.org>
>
>
> >
> > Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier
> > support for it")
> > Signed-off-by: Gilad Reti <gilad.reti@gmail.com>
> > ---
> >  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;
> > --
> > 2.27.0
> >