linux-kernel - Re: [GIT PULL] sched: Cputime update for 3.10

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:	Thu, 14 Mar 2013 13:39:35 +0100
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Stanislaw Gruszka <sgruszka@...hat.com>,
	Ingo Molnar <mingo@...nel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [GIT PULL] sched: Cputime update for 3.10

2013/3/14 Stanislaw Gruszka <sgruszka@...hat.com>:
> On Thu, Mar 14, 2013 at 08:14:27AM +0100, Ingo Molnar wrote:
>> Hm, is this a new bug? When was it introduced and is upstream affected as
>> well?
>
> Commit 0cf55e1ec08bb5a22e068309e2d8ba1180ab4239 start to use scalling
> for whole thread group, so increase chances of hitting multiplication
> overflow, depending on how many CPUs are on the system.

Yeah, it was introduced with that commit. Although problems was there
back when we started scaling cputime against precise sched runtime.
But certainly that commit 0cf55e1ec08bb5a22e068309e2d8ba1180ab4239
made the bug visible and happening in practice.

And indeed upstream is affected.
--
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/