Re: [PATCH] mm/hotplug: Verify hotplug memory range

From: KOSAKI Motohiro
Date: Thu Aug 08 2013 - 15:54:16 EST

On Thu, Aug 8, 2013 at 12:47 PM, Toshi Kani <toshi.kani@xxxxxx> wrote:
> add_memory() and remove_memory() can only handle a memory range aligned
> with section. There are problems when an unaligned range is added and
> then deleted as follows:
> - add_memory() with an unaligned range succeeds, but __add_pages()
> called from add_memory() adds a whole section of pages even though
> a given memory range is less than the section size.
> - remove_memory() to the added unaligned range hits BUG_ON() in
> __remove_pages().
> This patch changes add_memory() and remove_memory() to check if a given
> memory range is aligned with section at the beginning. As the result,
> add_memory() fails with -EINVAL when a given range is unaligned, and
> does not add such memory range. This prevents remove_memory() to be
> called with an unaligned range as well. Note that remove_memory() has
> to use BUG_ON() since this function cannot fail.
> Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
> ---
> mm/memory_hotplug.c | 22 ++++++++++++++++++++++

memory_hotplug.c is maintained by me and kamezawa-san. Please cc us
if you have a subsequent patch.

Acked-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
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