[PATCH][next] net: tcp: Remove redundant initialization of variable len

[PATCH][next] net: tcp: Remove redundant initialization of variable len

[Colin Ian King]

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 = th->doff << 2;
 	struct scatterlist sg;
 	u8 *hdr = hp->scratch;
+	int err, len;
 
 	/* We are not allowed to change tcphdr, make a local copy */
 	if (exclude_options) {
-- 
2.39.2

Re: [PATCH][next] net: tcp: Remove redundant initialization of variable len

[Eric Dumazet]

On Fri, Feb 16, 2024 at 1:54 PM 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 = th->doff << 2;
>         struct scatterlist sg;
>         u8 *hdr = 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 !

Re: [PATCH][next] net: tcp: Remove redundant initialization of variable len

[Dmitry Safonov]

On 2/16/24 13:00, Eric Dumazet wrote:
> On Fri, Feb 16, 2024 at 1:54 PM 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>

LGTM,

Reviewed-by: Dmitry Safonov <0x7f454c46@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 = th->doff << 2;
>>         struct scatterlist sg;
>>         u8 *hdr = 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 for Cc'ing!

> 
> Thanks !

Thanks,
             Dmitry

Re: [PATCH][next] net: tcp: Remove redundant initialization of variable len

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Fri, 16 Feb 2024 12:54:43 +0000 you 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]
> 
> [...]

Here is the summary with links:
  - [next] net: tcp: Remove redundant initialization of variable len
    https://git.kernel.org/netdev/net-next/c/465c1abcb644

You are awesome, thank you!
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