[PATCH 10/10] checkpatch: suggest nonnull attribute conversion

[Joe Perches]

On Wed, 2026-10-28 at 08:19 +0000, Dmitry Ilvokhin wrote:
> The kernel provides the __nonnull_args() macro as the preferred form for
> marking pointer arguments as non-NULL. Add a check suggesting the macro
> over the raw __attribute__((nonnull)) spelling, consistent with the
> existing attribute conversion suggestions.
> 
> Examples:
> 
>   WARNING: Prefer __nonnull_args(1, 2) over __attribute__((nonnull(1, 2)))
>   #11: FILE: drivers/soc/aspeed/aspeed-lpc-snoop.c:230:
>   +__attribute__((nonnull(1, 2)))
> 
>   WARNING: Prefer __nonnull_args() over __attribute__((nonnull))
>   #11: FILE: drivers/soc/aspeed/aspeed-lpc-snoop.c:283:
>   +__attribute__((nonnull))
> 
> Signed-off-by: Dmitry Ilvokhin <[d at ilvokhin.com](mailto:d at ilvokhin.com)>

Seems sensible, thanks.

> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -6856,6 +6856,7 @@ sub process {
>  				"no_caller_saved_registers"	=> "__no_caller_saved_registers",
>  				"noclone"			=> "__noclone",
>  				"noinline"			=> "noinline",
> +				"nonnull"			=> "__nonnull_args",
>  				"nonstring"			=> "__nonstring",
>  				"noreturn"			=> "__noreturn",
>  				"packed"			=> "__packed",
> @@ -6876,6 +6877,8 @@ sub process {
>  					if ($curr_attr eq "format" && $params) {
>  						$params =~ /^\s*\(\s*(\w+)\s*,\s*(.*)/;
>  						$new = "__$1\($2";
> +					} elsif ($curr_attr eq "nonnull" && $params eq "") {
> +						$new = "$new()";
>  					} else {
>  						$new = "$new$params";
>  					}
>