From: Andrew Morton <akpm@linux-foundation.org>
To: Lin Feng <linfeng@cn.fujitsu.com>
Cc: tj@kernel.org, mingo@kernel.org, yinghai@kernel.org,
liwanp@linux.vnet.ibm.com, benh@kernel.crashing.org,
tangchen@cn.fujitsu.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm: memblock: fix wrong memmove size in memblock_merge_regions()
Date: Mon, 7 Jan 2013 13:23:41 -0800 [thread overview]
Message-ID: <20130107132341.c8ca0060.akpm@linux-foundation.org> (raw)
In-Reply-To: <1357530096-28548-1-git-send-email-linfeng@cn.fujitsu.com>
On Mon, 7 Jan 2013 11:41:36 +0800
Lin Feng <linfeng@cn.fujitsu.com> wrote:
> The memmove span covers from (next+1) to the end of the array, and the index
> of next is (i+1), so the index of (next+1) is (i+2). So the size of remaining
> array elements is (type->cnt - (i + 2)).
What are the user-visible effects of this bug?
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -314,7 +314,8 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type)
> }
>
> this->size += next->size;
> - memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
> + /* move forward from next + 1, index of which is i + 2 */
> + memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
> type->cnt--;
> }
> }
> --
> 1.7.11.7
next prev parent reply other threads:[~2013-01-07 21:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-07 3:41 [PATCH v2] mm: memblock: fix wrong memmove size in memblock_merge_regions() Lin Feng
2013-01-07 17:01 ` Tejun Heo
2013-01-07 21:23 ` Andrew Morton [this message]
2013-01-08 1:44 ` Lin Feng
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