Merge branch 'akpm'

Quoth Andrew:
  "Random fixes.  And a simple new LED driver which I'm trying to sneak
   in while you're not looking."

Sneaking successful.

* akpm:
  score: fix off-by-one index into syscall table
  mm: fix rss count leakage during migration
  SHM_UNLOCK: fix Unevictable pages stranded after swap
  SHM_UNLOCK: fix long unpreemptible section
  kdump: define KEXEC_NOTE_BYTES arch specific for s390x
  mm/hugetlb.c: undo change to page mapcount in fault handler
  mm: memcg: update the correct soft limit tree during migration
  proc: clear_refs: do not clear reserved pages
  drivers/video/backlight/l4f00242t03.c: return proper error in l4f00242t03_probe if regulator_get() fails
  drivers/video/backlight/adp88x0_bl.c: fix bit testing logic
  kprobes: initialize before using a hlist
  ipc/mqueue: simplify reading msgqueue limit
  leds: add led driver for Bachmann's ot200
  mm: __count_immobile_pages(): make sure the node is online
  mm: fix NULL ptr dereference in __count_immobile_pages
  mm: fix warnings regarding enum migrate_mode

1 files changed, 19 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0027d8f4a1bb..d2186ecb36f7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5413,7 +5413,25 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
 
 bool is_pageblock_removable_nolock(struct page *page)
 {
-	struct zone *zone = page_zone(page);
+	struct zone *zone;
+	unsigned long pfn;
+
+	/*
+	 * We have to be careful here because we are iterating over memory
+	 * sections which are not zone aware so we might end up outside of
+	 * the zone but still within the section.
+	 * We have to take care about the node as well. If the node is offline
+	 * its NODE_DATA will be NULL - see page_zone.
+	 */
+	if (!node_online(page_to_nid(page)))
+		return false;
+
+	zone = page_zone(page);
+	pfn = page_to_pfn(page);
+	if (zone->zone_start_pfn > pfn ||
+			zone->zone_start_pfn + zone->spanned_pages <= pfn)
+		return false;
+
 	return __count_immobile_pages(zone, page, 0);
 }