Re: [PATCH][bpf-next] bpf: verifier: add a break statement in switch

From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Lawrence Brakmo <brakmo@fb.com>,
	Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH][bpf-next] bpf: verifier: add a break statement in switch
Date: Wed, 19 Jun 2019 10:44:30 -0700	[thread overview]
Message-ID: <CAEf4BzbVWSd=xVHdbM1R_u_V_HA7DESdF=gL9aH76VC25oq1dg@mail.gmail.com> (raw)
In-Reply-To: <20190619160708.GA30356@embeddedor>

On Wed, Jun 19, 2019 at 9:07 AM Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
>
> Notice that in this case, it's much clearer to explicitly add a break
> rather than letting the code to fall through. It also avoid potential
> future fall-through warnings[1].
>
> This patch is part of the ongoing efforts to enable
> -Wimplicit-fallthrough.
>
> [1] https://lore.kernel.org/patchwork/patch/1087056/
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---

Acked-by: Andrii Nakryiko <andriin@fb.com>

>  kernel/bpf/verifier.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 709ce4cef8ba..0b38cc917d21 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -6066,6 +6066,7 @@ static int check_return_code(struct bpf_verifier_env *env)
>                         range = tnum_range(0, 3);
>                         enforce_attach_type_range = tnum_range(2, 3);
>                 }
> +               break;
>         case BPF_PROG_TYPE_CGROUP_SOCK:
>         case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
>         case BPF_PROG_TYPE_SOCK_OPS:
> --
> 2.21.0
>