Re: [PATCH 0/2] bpf: Build with -Wcast-function-type

[Andrii Nakryiko]

On Mon, Sep 27, 2021 at 11:27 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> Hi,
>
> In order to keep ahead of cases in the kernel where Control Flow Integrity
> (CFI) may trip over function call casts, enabling -Wcast-function-type
> is helpful. To that end, replace BPF_CAST_CALL() as it triggers warnings
> with this option and is now one of the last places in the kernel in need
> of fixing.
>
> Thanks,
>
> -Kees
>
> Kees Cook (2):
>   bpf: Replace "want address" users of BPF_CAST_CALL with BPF_CALL_IMM
>   bpf: Replace callers of BPF_CAST_CALL with proper function typedef
>

Both patches look good to me. For the series:

Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>

>  include/linux/bpf.h    |  4 +++-
>  include/linux/filter.h |  7 +++----
>  kernel/bpf/arraymap.c  |  7 +++----
>  kernel/bpf/hashtab.c   | 13 ++++++-------
>  kernel/bpf/helpers.c   |  5 ++---
>  kernel/bpf/verifier.c  | 26 +++++++++-----------------
>  6 files changed, 26 insertions(+), 36 deletions(-)
>
> --
> 2.30.2
>