linux-kernel - Re: random insta-reboots on AMD Phenom II

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:   Sat, 30 Sep 2017 14:47:11 +0200
From:   Markus Trippelsdorf <markus@...ppelsdorf.de>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Adam Borowski <kilobyte@...band.pl>, linux-kernel@...r.kernel.org,
        Andy Lutomirski <luto@...nel.org>, x86-ml <x86@...nel.org>
Subject: Re: random insta-reboots on AMD Phenom II

On 2017.09.30 at 13:53 +0200, Borislav Petkov wrote:
> On Sat, Sep 30, 2017 at 01:29:03PM +0200, Adam Borowski wrote:
> > On Sat, Sep 30, 2017 at 01:11:37PM +0200, Borislav Petkov wrote:
> > > On Sat, Sep 30, 2017 at 04:05:16AM +0200, Adam Borowski wrote:
> > > > Any hints how to debug this?
> > > 
> > > Do
> > > rdmsr -a 0xc0010015
> > > as root and paste it here.
> > 
> > 1000010
> > 1000010
> > 1000010
> > 1000010
> > 1000010
> > 1000010
> > 
> > on both 4.13.4 and 4.14-rc2+.
> 
> Boot into -rc2+ and do as root:
> 
> # wrmsr -a 0xc0010015 0x1000018
> 
> If the issue gets fixed then Mr. Luto better revert the new lazy TLB
> flushing fun'n'games for 4.14 before it is too late and that kernel
> releases b0rked.

The issue does get fixed by setting TlbCacheDis to 1. I have been
running it for the last few weeks without any problems. 
Performance is not affected at all. So it might by easier to just set
the bit for older AMD processors as a boot quirk.
Changing the TLB code so late might not be a good idea...

-- 
Markus