linux-kernel - Re: [PATCH] x86/MCE: Remove MCP

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: <20161108210819.gx7bfw7pfx4e6tf4@pd.tnic>
Date:   Tue, 8 Nov 2016 22:08:20 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     "Luck, Tony" <tony.luck@...el.com>,
        linux-edac <linux-edac@...r.kernel.org>, X86 ML <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/MCE: Remove MCP_TIMESTAMP

On Tue, Nov 08, 2016 at 09:39:02PM +0100, Thomas Gleixner wrote:
> That does not make any sense. Where is m.tsc initialized? I couldn't find
> any place which does, except this and the conditional clear farther down in
> that function.

mce_gather_info->mce_setup does

m->tsc = rdtsc();

And we do that *everytime* but then we go and clear the damn thing. I
know, I know, I wanted to flip that logic too and read the TSC *only*
when we want a precise timestamp but that would require more changes as
mce_setup() is used at a bunch of places.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.