2024-02-16 12:55:02

by Colin Ian King

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

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 <[email protected]>
---
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



2024-02-16 13:00:45

by Eric Dumazet

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

On Fri, Feb 16, 2024 at 1:54 PM Colin Ian King <[email protected]> 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 <[email protected]>
> ---
> 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 !

2024-02-16 15:39:01

by Dmitry Safonov

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

On 2/16/24 13:00, Eric Dumazet wrote:
> On Fri, Feb 16, 2024 at 1:54 PM Colin Ian King <[email protected]> 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 <[email protected]>

LGTM,

Reviewed-by: Dmitry Safonov <[email protected]>

>> ---
>> 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


2024-02-20 10:50:48

by patchwork-bot+netdevbpf

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

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <[email protected]>:

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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