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Date: Thu, 13 Jul 2006 00:14:33 -0700
From: Andrew Morton <akpm@osdl.org>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: fix oom roll-back of __vmalloc_area_node
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On Tue, 11 Jul 2006 21:37:08 +0200
Jan Kiszka <jan.kiszka@web.de> wrote:

> __vunmap must not rely on area->nr_pages when picking the
> release methode for area->pages. It may be too small when
> __vmalloc_area_node failed early due to lacking memory.
> Instead, use a flag in vmstruct to differentiate.

So you mean that when this:

		if (unlikely(!area->pages[i])) {
			/* Successfully allocated i pages, free them in __vunmap() */
			area->nr_pages = i;
			goto fail;

happens, it could be that i <= PAGE_SIZE/sizeof(struct page *) and __vunmap
kfree()s something which it should have vfree()d, yes?

That sounds like a dead box, or worse.

I think the change would be a good one even if it didn't fix a bug, thanks.