Re: [PATCH bpf-next 02/13] bpf: generalize is_scalar_branch_taken() logic

Andrii Nakryiko
2023-11-03T20:59:26Z

On Fri, Nov 3, 2023 at 9:47 AM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> On Thu, 2023-11-02 at 17:08 -0700, Andrii Nakryiko wrote:
> > Generalize is_branch_taken logic for SCALAR_VALUE register to handle
> > cases when both registers are not constants. Previously supported
> > <range> vs <scalar> cases are a natural subset of more generic <range>
> > vs <range> set of cases.
> >
> > Generalized logic relies on straightforward segment intersection checks.
> >
> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
>
> Acked-by: Eduard Zingerman <eddyz87@gmail.com>
>
> (With the same nitpick that '<' cases could be converted to '>' cases).
>

Ok.

> > ---
> > kernel/bpf/verifier.c | 103 ++++++++++++++++++++++++++----------------
> > 1 file changed, 63 insertions(+), 40 deletions(-)
> > …