linux-kernel - Re: [GIT PULL] First batch of KVM changes for 4.1

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:	Mon, 20 Apr 2015 13:27:58 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Paolo Bonzini <pbonzini@...hat.com>
Cc:	Marcelo Tosatti <mtosatti@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Gleb Natapov <gleb@...nel.org>, kvm list <kvm@...r.kernel.org>,
	Ralf Baechle <ralf@...ux-mips.org>,
	Andrew Lutomirski <luto@...nel.org>
Subject: Re: [GIT PULL] First batch of KVM changes for 4.1

On Mon, Apr 20, 2015 at 9:59 AM, Paolo Bonzini <pbonzini@...hat.com> wrote:
>
>
> On 17/04/2015 22:18, Marcelo Tosatti wrote:
>> The bug which this is fixing is very rare, have no memory of a report.
>>
>> In fact, its even difficult to create a synthetic reproducer.
>
> But then why was the task migration notifier even in Jeremy's original
> code for Xen?  Was it supposed to work even on non-synchronized TSC?
>
> If that's the case, then it could be reverted indeed; but then why did
> you commit this patch to 4.1?  Did you think of something that would
> cause the seqcount-like protocol to fail, and that turned out not to be
> the case later?  I was only following the mailing list sparsely in March.

I don't think anyone ever tried that hard to test this stuff.  There
was an infinte loop that Firefox was triggering as a KVM guest
somewhat reliably until a couple months ago in the same vdso code.  :(

--Andy
--
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/