Re: [RFC PATCH v2] efi: const correct EFI functions

[Jan Beulich <jbeulich@xxxxxxxx>]

On 15.09.2020 12:02, Trammell Hudson wrote:
> @@ -149,10 +150,23 @@ static struct file __initdata cfg;
>  static struct file __initdata kernel;
>  static struct file __initdata ramdisk;
>  static struct file __initdata xsm;
> -static CHAR16 __initdata newline[] = L"\r\n";
> -
> -#define PrintStr(s) StdOut->OutputString(StdOut, s)
> -#define PrintErr(s) StdErr->OutputString(StdErr, s)
> +static const CHAR16 __initconst newline[] = L"\r\n";
> +
> +/* Cast away const-ness on EFI entry points */
> +#define PrintStr(s) StdOut->OutputString(StdOut, (CHAR16 *)(s))
> +#define PrintErr(s) StdErr->OutputString(StdErr, (CHAR16 *)(s))
> +#define efi_file_open(file,handle,name,mode,attr) \
> +    (file)->Open(file, handle, (CHAR16 *)(name), mode, attr)
> +#define efi_handle_protocol(handle, protocol, interface) \
> +    efi_bs->HandleProtocol(handle, (EFI_GUID *)(protocol), interface)
> +#define efi_locate_protocol(protocol, registration, interface) \
> +    efi_bs->LocateProtocol((EFI_GUID *)(protocol), (void *)(registration), \
> +                           interface)
> +#define efi_locate_handle(type, protocol, key, size, buffer) \
> +    efi_bs->LocateHandle(type, (EFI_GUID *)(protocol), (void *)(key), \
> +                         size, buffer)
> +#define shim_verify(shim, ptr, len) \
> +    (shim)->Verify((void *)(ptr), len)

In order for these casts to be halfway safe, they need to happen in
inline functions, not macros. That way it'll be sufficiently clear
and certain that it's really _only_ the const which gets changed,
but not e.g. also the pointed-to type.

Apart from this I think the whole change wants splitting up, to
(about) one basic change at a time.

Jan