Re: [PATCH v3 RESEND] checkpatch: suppress strscpy warnings for userspace tools

[Joe Perches <joe@perches.com>]

On Tue, 2025-09-23 at 22:47 +0530, Suchit Karunakaran wrote:
> The checkpatch.pl script currently warns against the use of strcpy,
> strlcpy, and strncpy, recommending strscpy as a safer alternative.
> However, these warnings are also triggered for code under tools/ and
> scripts/, which are userspace utilities where strscpy is not available.
> This patch suppresses these warnings for files in tools/ and scripts/.
> 
> Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.com>

Acked-by: Joe Perches <joe@perches.com>

> ---
> 
> Changes since v1:
> - Create is_userspace function to check if the file is in userspace
>   directories
> 
> Changes since v2:
> - Change regex pattern to match top level directories only
> 
>  scripts/checkpatch.pl | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index e722dd6fa8ef..fe580b0810f9 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2636,6 +2636,11 @@ sub exclude_global_initialisers {
>  		$realfile =~ m@/bpf/.*\.bpf\.c$@;
>  }
>  
> +sub is_userspace {
> +    my ($realfile) = @_;
> +    return ($realfile =~ m@^tools/@ || $realfile =~ m@^scripts/@);
> +}
> +
>  sub process {
>  	my $filename = shift;
>  
> @@ -7018,21 +7023,20 @@ sub process {
>  #				}
>  #			}
>  #		}
> -
>  # strcpy uses that should likely be strscpy
> -		if ($line =~ /\bstrcpy\s*\(/) {
> +		if ($line =~ /\bstrcpy\s*\(/ && !is_userspace($realfile)) {
>  			WARN("STRCPY",
>  			     "Prefer strscpy over strcpy - see: https://github.com/KSPP/linux/issues/88\n" . $herecurr);
>  		}
>  
>  # strlcpy uses that should likely be strscpy
> -		if ($line =~ /\bstrlcpy\s*\(/) {
> +		if ($line =~ /\bstrlcpy\s*\(/ && !is_userspace($realfile)) {
>  			WARN("STRLCPY",
>  			     "Prefer strscpy over strlcpy - see: https://github.com/KSPP/linux/issues/89\n" . $herecurr);
>  		}
>  
>  # strncpy uses that should likely be strscpy or strscpy_pad
> -		if ($line =~ /\bstrncpy\s*\(/) {
> +		if ($line =~ /\bstrncpy\s*\(/ && !is_userspace($realfile)) {
>  			WARN("STRNCPY",
>  			     "Prefer strscpy, strscpy_pad, or __nonstring over strncpy - see: https://github.com/KSPP/linux/issues/90\n" . $herecurr);
>  		}