2021-06-15 10:56:50

by Jiapeng Chong

Subject: [PATCH] mptcp: Remove redundant assignment to remaining

Variable remaining is assigned, but this value is never read as it is
not used later on, hence it is a redundant assignment and can be
removed.

Clean up the following clang-analyzer warning:

net/mptcp/options.c:779:3: warning: Value stored to 'remaining' is never
read [clang-analyzer-deadcode.DeadStores].

net/mptcp/options.c:547:3: warning: Value stored to 'remaining' is never
read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
net/mptcp/options.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 9b263f2..f99272f 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -544,7 +544,6 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,

map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64;

- remaining -= map_size;
dss_size = map_size;
if (mpext)
opts->ext_copy = *mpext;
@@ -776,7 +775,6 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,

if (mptcp_established_options_mp_prio(sk, &opt_size, remaining, opts)) {
*size += opt_size;
- remaining -= opt_size;
ret = true;
}

--
1.8.3.1

2021-06-15 23:54:41

by Mat Martineau

Subject: Re: [PATCH] mptcp: Remove redundant assignment to remaining

On Tue, 15 Jun 2021, Jiapeng Chong wrote:

> Variable remaining is assigned, but this value is never read as it is
> not used later on, hence it is a redundant assignment and can be
> removed.
>
> Clean up the following clang-analyzer warning:
>
> net/mptcp/options.c:779:3: warning: Value stored to 'remaining' is never
> read [clang-analyzer-deadcode.DeadStores].
>
> net/mptcp/options.c:547:3: warning: Value stored to 'remaining' is never
> read [clang-analyzer-deadcode.DeadStores].
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> net/mptcp/options.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/net/mptcp/options.c b/net/mptcp/options.c
> index 9b263f2..f99272f 100644
> --- a/net/mptcp/options.c
> +++ b/net/mptcp/options.c
> @@ -544,7 +544,6 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb,
>
> map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64;
>
> - remaining -= map_size;

Hi Jiapeng, thank you for your MPTCP patch!

This change in mptcp_established_options_dss() removes the only reference
to 'remaining' in that function, so the variable should also be removed
from the function parameters. It also appears to be unused in
mptcp_established_options_mp().

I'd like to handle this patch through the MPTCP tree so we can manage
conflicts with other in-progress patches. This patch does apply to
net-next cleanly but not our subsystem branch. You can find our git repo
at https://github.com/multipath-tcp/mptcp_net-next, and develop patches
using the 'export' branch. If you email a v2 patch to
[email protected] (no need to cc other lists), Matthieu and I can make
sure it is integrated in the MPTCP repository and handle sending it to
netdev along with other patches from the MPTCP community.

> dss_size = map_size;
> if (mpext)
> opts->ext_copy = *mpext;
> @@ -776,7 +775,6 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
>
> if (mptcp_established_options_mp_prio(sk, &opt_size, remaining, opts)) {
> *size += opt_size;
> - remaining -= opt_size;
> ret = true;
> }
>
> --
> 1.8.3.1

Best regards,

--
Mat Martineau
Intel