linux-kernel - Re: [PATCH -v2] x86/sev: Make the #VC exception stacks part of the default stacks storage

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]

Date:   Tue, 5 Oct 2021 11:28:01 -0500
From:   Tom Lendacky <thomas.lendacky@....com>
To:     Borislav Petkov <bp@...en8.de>, Joerg Roedel <jroedel@...e.de>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Brijesh Singh <brijesh.singh@....com>
Subject: Re: [PATCH -v2] x86/sev: Make the #VC exception stacks part of the
 default stacks storage

On 10/4/21 4:41 PM, Borislav Petkov wrote:
> Yap,
> 
> here's v2, now tested. It seems we do need that optional_stack_size
> second arg to ESTACKS_MEMBERS(), thx Tom.
> 
> ---
> From: Borislav Petkov <bp@...e.de>

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

> 
> The size of the exception stacks was increased by the commit in Fixes,
> resulting in stack sizes greater than a page in size. The #VC exception
> handling was only mapping the first (bottom) page, resulting in an
> SEV-ES guest failing to boot.
> 
> Make the #VC exception stacks part of the default exception stacks
> storage and allocate them with a CONFIG_AMD_MEM_ENCRYPT=y .config. Map
> them only when a SEV-ES guest has been detected.
> 
> Rip out the custom VC stacks mapping and storage code.
> 
>   [ bp: Steal and adapt Tom's commit message. ]
> 
> Fixes: 7fae4c24a2b8 ("x86: Increase exception stack sizes")
> Signed-off-by: Borislav Petkov <bp@...e.de>