Re: [PATCH v5 1/2] ACPI: utils: Add api to read _SUB from ACPI

[Andy Shevchenko]

On Thu, Jun 30, 2022 at 5:17 PM Stefan Binding
<sbinding@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Add a wrapper function to read the _SUB string from ACPI.

...

> +       if (obj->type == ACPI_TYPE_STRING) {
> +               if (strlen(obj->string.pointer) < ACPI_MAX_SUB_BUF_SIZE &&
> +                   strlen(obj->string.pointer) > 0) {
> +                       sub = kstrdup(obj->string.pointer, GFP_KERNEL);
> +                       if (!sub)
> +                               sub = ERR_PTR(-ENOMEM);
> +               } else {
> +                       acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n",
> +                                       strlen(obj->string.pointer));

Three times to evaluate strlen()... Can we do better, please?

> +                       sub = ERR_PTR(-EINVAL);
> +               }
> +       } else {
> +               acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
> +               sub = ERR_PTR(-EINVAL);
> +       }

-- 
With Best Regards,
Andy Shevchenko