mm/hugetlb: add same zone check in pfn_range_valid_gigantic()

This patchset deals with some problematic sites that iterate pfn ranges.

There is a system thats node's pfns are overlapped as follows:

  -----pfn-------->
  N0 N1 N2 N0 N1 N2

Therefore, we need to take care of this overlapping when iterating pfn
range.

I audit many iterating sites that uses pfn_valid(), pfn_valid_within(),
zone_start_pfn and etc.  and others looks safe to me.  This is a
preparation step for a new CMA implementation, ZONE_CMA
(https://lkml.org/lkml/2015/2/12/95), because it would be easily
overlapped with other zones.  But, zone overlap check is also needed for
the general case so I send it separately.

This patch (of 5):

alloc_gigantic_page() uses alloc_contig_range() and this requires that
the requested range is in a single zone.  To satisfy this requirement,
add this check to pfn_range_valid_gigantic().

Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions