Re: [RFC PATCH 2/2] efi: remove deprecated 'efivars' sysfs interface

Kees Cook
2022-06-16T16:20:57Z

On Thu, Jun 16, 2022 at 02:47:40PM +0200, Ard Biesheuvel wrote:
> Commit 5d9db883761a ("efi: Add support for a UEFI variable filesystem")
> dated Oct 5, 2012, introduced a new efivarfs pseudo-filesystem to
> replace the efivars sysfs interface that was used up to that point to
> expose EFI variables to user space.
>
> The main problem with the sysfs interface was that it only supported up
> to 1024 bytes of payload per file, whereas the underlying variables
> themselves are only bounded by a platform specific per-variable and
> global limit that is typically much higher than 1024 bytes.
>
> The deprecated sysfs interface is only enabled on x86 and Itanium, other
> EFI enabled architectures only support the efivarfs pseudo-filesystem.

Does anything still use the sysfs interface? (e.g. do paths to it exist
in anything meaningful in, say, a Debian code search?)

--
Kees Cook