linux-kernel - Re: Candidate Linux ABI for Intel AMX and hypothetical new related features

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, 30 Mar 2021 13:01:06 -0400
From:   Len Brown <lenb@...nel.org>
To:     Andy Lutomirski <luto@...nel.org>
Cc:     Greg KH <gregkh@...uxfoundation.org>,
        "Bae, Chang Seok" <chang.seok.bae@...el.com>,
        Dave Hansen <dave.hansen@...el.com>, X86 ML <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        libc-alpha <libc-alpha@...rceware.org>,
        Florian Weimer <fweimer@...hat.com>,
        Rich Felker <dalias@...c.org>, Kyle Huey <me@...ehuey.com>,
        Keno Fischer <keno@...iacomputing.com>,
        Linux API <linux-api@...r.kernel.org>
Subject: Re: Candidate Linux ABI for Intel AMX and hypothetical new related features

Andy,

I agree, completely, with your description of the challenge,
thank you for focusing the discussion on that problem statement.

Question:

Is it required (by the "ABI") that a user program has everything
on the stack for user-space XSAVE/XRESTOR to get back
to the state of the program just before receiving the signal?

My understanding is that there are programs that do this.
However, if it is not guaranteed to work, that could greatly simplify
what we are required to put on the signal stack.

thanks,
-Len