Re: [PATCH] x86/platform/uv: refactor deprecated strcpy and strncpy

[Andy Shevchenko]

On Wed, Aug 23, 2023 at 1:32 AM Justin Stitt <justinstitt@xxxxxxxxxx> wrote:
>
> Both `strncpy` and `strcpy` are deprecated for use on NUL-terminated
> destination strings [1].
>
> A suitable replacement is `strscpy` [2] due to the fact that it
> guarantees NUL-termination on its destination buffer argument which is
> _not_ the case for `strncpy` or `strcpy`!
>
> In this case, we can drop both the forced NUL-termination and the `... -1` from:
> |       strncpy(arg, val, ACTION_LEN - 1);
> as `strscpy` implicitly has this behavior.

...

>         char arg[ACTION_LEN], *p;
>
>         /* (remove possible '\n') */
> -       strncpy(arg, val, ACTION_LEN - 1);
> -       arg[ACTION_LEN - 1] = '\0';
> +       strscpy(arg, val, ACTION_LEN);
>         p = strchr(arg, '\n');
>         if (p)
>                 *p = '\0';

https://lore.kernel.org/all/202212091545310085328@xxxxxxxxxx/

...

> +               strscpy(uv_nmi_action, arg, strlen(uv_nmi_action));

strlen() on the destination?!

...

> -                       strncpy(uv_nmi_action, "dump", strlen(uv_nmi_action));
> +                       strscpy(uv_nmi_action, "dump", strlen(uv_nmi_action));

Again, this is weird.

-- 
With Best Regards,
Andy Shevchenko