linux-kernel - Re: [PATCH v4 1/3] x86/boot: Drop unused sev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2c500636-ba5a-4266-8be2-a13529aa7704@amd.com>
Date: Thu, 11 Sep 2025 16:35:28 -0500
From: Tom Lendacky <thomas.lendacky@....com>
To: Ard Biesheuvel <ardb+git@...gle.com>, linux-efi@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, x86@...nel.org,
 Ard Biesheuvel <ardb@...nel.org>, Borislav Petkov <bp@...en8.de>
Subject: Re: [PATCH v4 1/3] x86/boot: Drop unused sev_enable() fallback

On 9/9/25 03:06, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@...nel.org>
> 
> The misc.h header is not included by the EFI stub, which is the only C
> caller of sev_enable(). This means the fallback for cases where
> CONFIG_AMD_MEM_ENCRYPT is not set is never used, so it can be dropped.
> 
> Signed-off-by: Ard Biesheuvel <ardb@...nel.org>

Reviewed-by: Tom Lendacky <thomas.lendacky@....com>

> ---
>  arch/x86/boot/compressed/misc.h | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index db1048621ea2..fd855e32c9b9 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -152,17 +152,6 @@ bool insn_has_rep_prefix(struct insn *insn);
>  void sev_insn_decode_init(void);
>  bool early_setup_ghcb(void);
>  #else
> -static inline void sev_enable(struct boot_params *bp)
> -{
> -	/*
> -	 * bp->cc_blob_address should only be set by boot/compressed kernel.
> -	 * Initialize it to 0 unconditionally (thus here in this stub too) to
> -	 * ensure that uninitialized values from buggy bootloaders aren't
> -	 * propagated.
> -	 */
> -	if (bp)
> -		bp->cc_blob_address = 0;
> -}
>  static inline void snp_check_features(void) { }
>  static inline void sev_es_shutdown_ghcb(void) { }
>  static inline bool sev_es_check_ghcb_fault(unsigned long address)