Re: [PATCH net-next] selftests: net: tcp_ao: make the netstat column pointer const

[Hangbin Liu <hangbin.liu@linux.dev>]

On Tue, Nov 03, 2026 at 11:54:19AM -0500, Sasha Levin wrote:
> lookup_get_column() stores the result of strchr() on a const string in
> a plain char pointer. Since glibc 2.43, strchr() returns a const char
> pointer for a const argument when C23 features are enabled, as they
> are with _GNU_SOURCE, so gcc and clang warn:
> 
>   lib/proc.c:61:16: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
> 
> The pointer is only used to compute the length, so make it const.
> 
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> Found with gcc 16 and clang 21 on glibc 2.43; KernelCI's gcc 15 builds
> show the same warning.
> 
>  tools/testing/selftests/net/tcp_ao/lib/proc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/net/tcp_ao/lib/proc.c b/tools/testing/selftests/net/tcp_ao/lib/proc.c
> index 8b984fa042869..50062b527a393 100644
> --- a/tools/testing/selftests/net/tcp_ao/lib/proc.c
> +++ b/tools/testing/selftests/net/tcp_ao/lib/proc.c
> @@ -56,7 +56,7 @@ static struct netstat *lookup_get(struct netstat *ns,
>  
>  static struct netstat *lookup_get_column(struct netstat *ns, const char *line)
>  {
> -	char *column;
> +	const char *column;
>  
>  	column = strchr(line, ':');
>  	if (!column)
> -- 
> 2.53.0
> 

Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn>