linux-kernel - Re: [PATCH] posixtimers: Fix posix clock monotonicity v2

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:	Wed, 18 Mar 2009 11:58:07 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
Cc:	linux-kernel@...r.kernel.org, stable@...nel.org,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH] posixtimers: Fix posix clock monotonicity v2

On Wed, 2009-03-18 at 19:41 +0900, Hidetoshi Seto wrote:
> Impact: Regression fix (against clock_gettime() backwarding bug)
> 
> This patch re-introduces a couple of function, task_sched_runtime
> and thread_group_sched_runtime, which was once removed at the
> time of 2.6.28-rc1.
> 
> These functions protect the sampling of thread/process clock with
> rq lock.  This rq lock is required not to update rq->clock durling
> the sampling.
> i.e.
>   The clock_gettime() may return
>    ((accounted runtime before update) + (delta after update))
>   that is less than what it should be.
> 
> v1 -> v2:
> 	- Revises comments for functions and patch description.
> 	- Add note about accuracy of thread group's runtime.
> 
> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Ingo Molnar <mingo@...e.hu>
> Cc: stable@...nel.org	[2.6.28.x]

Acked-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>

Thanks Hidetoshi-san.

--
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/