From: Mel Gorman <mgorman@suse.de>
To: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
Pekka Enberg <penberg@kernel.org>,
Paul McQuade <paulmcquad@gmail.com>,
Tang Chen <tangchen@cn.fujitsu.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] bootmem: avoid freeing to bootmem after bootmem is done
Date: Mon, 27 Jul 2015 11:59:51 +0100 [thread overview]
Message-ID: <20150727105951.GO2561@suse.de> (raw)
In-Reply-To: <1437771226-31255-1-git-send-email-cmetcalf@ezchip.com>
On Fri, Jul 24, 2015 at 04:53:46PM -0400, Chris Metcalf wrote:
> Bootmem isn't popular any more, but some architectures still use
> it, and freeing to bootmem after calling free_all_bootmem_core()
> can end up scribbling over random memory. Instead, make sure the
> kernel panics by ensuring the node_bootmem_map field is non-NULL
> when are freeing or marking bootmem.
>
> An instance of this bug was just fixed in the tile architecture
> ("tile: use free_bootmem_late() for initrd") and catching this case
> more widely seems like a good thing.
>
> Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
In general it looks fine but you could just WARN_ON, return and still
boot the kernel too. Obviously it would need to be fixed but Linus will
push back if he spots a BUG_ON when there was a recovery option.
--
Mel Gorman
SUSE Labs
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next prev parent reply other threads:[~2015-07-27 10:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-24 20:53 [PATCH] bootmem: avoid freeing to bootmem after bootmem is done Chris Metcalf
2015-07-27 10:59 ` Mel Gorman [this message]
2015-07-27 15:36 ` [PATCH v2] " Chris Metcalf
2015-07-27 16:05 ` Mel Gorman
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