Re: [PATCH v1 1/1] ACPI: processor: idle: Replace strlcat() with better alternative

[Kees Cook]

On Mon, Mar 16, 2026 at 06:01:58PM +0100, Andy Shevchenko wrote:
> strlcpy() and strlcat() are confusing APIs and the former one already gone
> from the kernel. In preparation to kill strlcat() replace it with the better
> alternative.

Yes please. There are a few places I looked at in the past that might
benefit from being changed to seq_buf or similar (where snprintf doesn't
cut it), but otherwise the removal of strlcat should be straight forward
and would be well appreciated. :)

> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Reviewed-by: Kees Cook <kees@xxxxxxxxxx>

-Kees

> ---
>  drivers/acpi/processor_idle.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 45b5d17443cf..498d88f5d5c9 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1010,9 +1010,7 @@ static bool combine_lpi_states(struct acpi_lpi_state *local,
>  	result->arch_flags = parent->arch_flags;
>  	result->index = parent->index;
>  
> -	strscpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
> -	strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
> -	strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
> +	snprintf(result->desc, ACPI_CX_DESC_LEN, "%s+%s", local->desc, parent->desc);
>  	return true;
>  }
>  
> -- 
> 2.50.1
> 

-- 
Kees Cook