linux-kernel - Re: x86, vmi: TSC going backwards check in vmi clocksource

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: <20090219181132.GA11477@elte.hu>
Date:	Thu, 19 Feb 2009 19:11:32 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Alok Kataria <akataria@...are.com>
Cc:	the arch/x86 maintainers <x86@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Zach Amsden <zach@...are.com>
Subject: Re: x86, vmi: TSC going backwards check in vmi clocksource


* Alok Kataria <akataria@...are.com> wrote:

> On Thu, 2009-02-19 at 03:18 -0800, Ingo Molnar wrote:
> > * Alok Kataria <akataria@...are.com> wrote:
> > 
> > > From: Alok N Kataria <akataria@...are.com>
> > > 
> > > Similar to the check for TSC going backwards in the TSC 
> > > clocksource, we also need this check for VMI clocksource.
> > 
> > ok. Precisely what kind of bug/symptoms does this fix?
> 
> If the read CYCLES_REAL counter value is less than the cycle_last value,
> it may result in time jumps.
> I also saw some messages about  process being stuck for more than
> 120sec, which was traced back to this.

Applied to tip:x86/urgent, thanks Alok!

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/