Re: [PATCH v12 06/19] x86: Add early SHA-256 support for Secure Launch early measurements

[Jarkko Sakkinen <jarkko@kernel.org>]

On Thu, Dec 19, 2024 at 11:42:03AM -0800, Ross Philipson wrote:
> From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
> 
> The SHA-256 algorithm is necessary to measure configuration information into
> the TPM as early as possible before using the values. This implementation
> uses the established approach of #including the SHA-256 libraries directly in
> the code since the compressed kernel is not uncompressed at this point.
> 
> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
> Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
> ---
>  arch/x86/boot/compressed/Makefile | 2 +-
>  arch/x86/boot/compressed/sha256.c | 6 ++++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
>  create mode 100644 arch/x86/boot/compressed/sha256.c
> 
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index 7eb03afb841b..40dc0b9babd5 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -107,7 +107,7 @@ vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
>  vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_mixed.o
>  vmlinux-libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
>  
> -vmlinux-objs-$(CONFIG_SECURE_LAUNCH) += $(obj)/sha1.o
> +vmlinux-objs-$(CONFIG_SECURE_LAUNCH) += $(obj)/sha1.o $(obj)/sha256.o
>  
>  $(obj)/vmlinux: $(vmlinux-objs-y) $(vmlinux-libs-y) FORCE
>  	$(call if_changed,ld)
> diff --git a/arch/x86/boot/compressed/sha256.c b/arch/x86/boot/compressed/sha256.c
> new file mode 100644
> index 000000000000..293742a90ddc
> --- /dev/null
> +++ b/arch/x86/boot/compressed/sha256.c
> @@ -0,0 +1,6 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2024 Apertus Solutions, LLC
> + */
> +
> +#include "../../../../lib/crypto/sha256.c"
> -- 
> 2.39.3
> 

Ditto, nothing particular on this at this point of time. Probably 80-90%
what it should be. 

BR, Jarkko