Received-SPF: pass (google.com: domain of linux-kernel+bounces-68605-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <20240216125443.2107244-1-colin.i.king@gmail.com>
In-Reply-To: <20240216125443.2107244-1-colin.i.king@gmail.com>
From: Eric Dumazet <edumazet@google.com>
Date: Fri, 16 Feb 2024 14:00:04 +0100
Message-ID: <CANn89iJM=fVSkzz9HRU+HXYm+R+owKqah0TT8sY-soEXf2HiNA@mail.gmail.com>
Subject: Re: [PATCH][next] net: tcp: Remove redundant initialization of
 variable len
To: Colin Ian King <colin.i.king@gmail.com>, Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "David S . Miller" <davem@davemloft.net>, David Ahern <dsahern@kernel.org>, 
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org, 
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Fri, Feb 16, 2024 at 1:54=E2=80=AFPM Colin Ian King <colin.i.king@gmail.=
com> wrote:
>
> The variable len being initialized with a value that is never read, an
> if statement is initializing it in both paths of the if statement.
> The initialization is redundant and can be removed.
>
> Cleans up clang scan build warning:
> net/ipv4/tcp_ao.c:512:11: warning: Value stored to 'len' during its
> initialization is never read [deadcode.DeadStores]
>
> Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
> ---
>  net/ipv4/tcp_ao.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
> index 87db432c6bb4..3afeeb68e8a7 100644
> --- a/net/ipv4/tcp_ao.c
> +++ b/net/ipv4/tcp_ao.c
> @@ -509,9 +509,9 @@ static int tcp_ao_hash_header(struct tcp_sigpool *hp,
>                               bool exclude_options, u8 *hash,
>                               int hash_offset, int hash_len)
>  {
> -       int err, len =3D th->doff << 2;
>         struct scatterlist sg;
>         u8 *hdr =3D hp->scratch;
> +       int err, len;
>
>         /* We are not allowed to change tcphdr, make a local copy */
>         if (exclude_options) {
> --
> 2.39.2
>

Cc Dmitry Safonov

Dmitry, can you take a look ?

Thanks !