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From: Dave Hansen <haveblue@us.ibm.com>
To: Kirill Korotaev <dev@sw.ru>
Cc: Andrew Morton <akpm@osdl.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	alan@lxorguk.ukuu.org.uk, muli@il.ibm.com, B.Steinbrink@gmx.de,
	stable@kernel.org
Subject: Re: [PATCH] sys_getppid oopses on debug kernel (v2)
Date: Tue, 08 Aug 2006 09:09:21 -0700	[thread overview]
Message-ID: <1155053361.19249.60.camel@localhost.localdomain> (raw)
In-Reply-To: <44D8B2C5.1080905@sw.ru>

On Tue, 2006-08-08 at 19:50 +0400, Kirill Korotaev wrote:
> sys_getppid() optimization can access a freed memory.
> On kernels with DEBUG_SLAB turned ON, this results in Oops.
> As Dave Hansen noted, this optimization is also unsafe
> for memory hotplug. 

Yeah, I just tried coding up something to do a seqlock to note when
tasks are freed, but it doesn't work.  Unless somebody is really going
crazy with getppid() on a very large system, this should be just fine.

-- Dave



  reply	other threads:[~2006-08-08 16:09 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-08 15:50 Kirill Korotaev
2006-08-08 16:09 ` Dave Hansen [this message]
2006-08-09 14:38 Oleg Nesterov
2006-08-09 12:08 ` Kirill Korotaev
2006-08-09 16:54   ` Oleg Nesterov
2006-08-09 13:02     ` Kirill Korotaev

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