Re: [PATCH v1 1/4] mm/memory_hotplug: use "unsigned long" for PFN in zone_for_pfn_range()

From: Heiko Carstens
Date: Wed Jul 14 2021 - 16:14:52 EST


On Mon, Jul 12, 2021 at 02:40:49PM +0200, David Hildenbrand wrote:
> Checkpatch complained on a follow-up patch that we are using "unsigned"
> here, which defaults to "unsigned int" and checkpatch is correct.
>
> Use "unsigned long" instead, just as we do in other places when handling
> PFNs. This can bite us once we have physical addresses in the range of
> multiple TB.
>
> Fixes: e5e689302633 ("mm, memory_hotplug: display allowed zones in the preferred ordering")
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> include/linux/memory_hotplug.h | 4 ++--
> mm/memory_hotplug.c | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)

I'd propose to add Cc: <stable@xxxxxxxxxxxxxxx> since I actually had
the fun to try to debug something like this a couple of years ago:
6cdb18ad98a4 ("mm/vmstat: fix overflow in mod_zone_page_state()")