From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: David Rientjes <rientjes@google.com>
Cc: kosaki.motohiro@jp.fujitsu.com,
Dave Hansen <dave@linux.vnet.ibm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Nazarewicz <mina86@mina86.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/2] break out page allocation warning code
Date: Wed, 20 Apr 2011 09:39:00 +0900 (JST) [thread overview]
Message-ID: <20110420093900.45F6.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1104191419470.510@chino.kir.corp.google.com>
> On Tue, 19 Apr 2011, KOSAKI Motohiro wrote:
>
> > The rule is,
> >
> > 1) writing comm
> > need task_lock
> > 2) read _another_ thread's comm
> > need task_lock
> > 3) read own comm
> > no need task_lock
> >
>
> That was true a while ago, but you now need to protect every thread's
> ->comm with get_task_comm() or ensuring task_lock() is held to protect
> against /proc/pid/comm which can change other thread's ->comm. That was
> different before when prctl(PR_SET_NAME) would only operate on current, so
> no lock was needed when reading current->comm.
Right. /proc/pid/comm is evil. We have to fix it. otherwise we need change
all of current->comm user. It's very lots!
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next prev parent reply other threads:[~2011-04-20 0:39 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-15 17:04 Dave Hansen
2011-04-15 17:04 ` [PATCH 2/2] print vmalloc() state after allocation failures Dave Hansen
2011-04-15 17:20 ` Michal Nazarewicz
2011-04-15 17:44 ` Dave Hansen
2011-04-17 0:03 ` David Rientjes
2011-04-18 15:21 ` Dave Hansen
2011-04-17 0:02 ` [PATCH 1/2] break out page allocation warning code David Rientjes
2011-04-18 15:10 ` Dave Hansen
2011-04-18 20:25 ` David Rientjes
2011-04-18 20:57 ` Dave Hansen
2011-04-19 21:23 ` David Rientjes
2011-04-18 21:03 ` Dave Hansen
2011-04-18 21:22 ` Dave Hansen
2011-04-19 0:44 ` KOSAKI Motohiro
2011-04-19 21:21 ` David Rientjes
2011-04-20 0:39 ` KOSAKI Motohiro [this message]
2011-04-20 20:24 ` David Rientjes
2011-04-20 20:34 ` john stultz
2011-04-21 1:29 ` KOSAKI Motohiro
2011-04-25 4:21 ` KOSAKI Motohiro
2011-04-26 19:27 ` john stultz
2011-04-27 23:51 ` David Rientjes
2011-04-28 0:32 ` john stultz
2011-04-28 1:29 ` john stultz
2011-04-28 22:48 ` David Rientjes
2011-04-28 23:48 ` john stultz
2011-04-29 0:04 ` john stultz
2011-04-26 21:25 ` john stultz
2011-04-28 3:05 ` KOSAKI Motohiro
2011-04-20 1:41 ` Dave Hansen
2011-04-20 1:50 ` KOSAKI Motohiro
2011-04-20 2:19 ` KOSAKI Motohiro
2011-04-20 2:46 ` Dave Hansen
-- strict thread matches above, loose matches on Subject: below --
2011-04-19 16:21 Dave Hansen
2011-04-08 20:22 Dave Hansen
2011-04-08 20:37 ` David Rientjes
2011-04-08 20:43 ` Dave Hansen
2011-04-08 20:54 ` Michał Nazarewicz
2011-04-08 21:02 ` Dave Hansen
2011-04-11 10:20 ` Michal Nazarewicz
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