onlining/offlining code works on whole sections, so let's enforce that. Existing code only allows to add memory in memory block size. And only whole memory blocks can be onlined/offlined. Memory blocks are always aligned to sections, so this should not break anything. online_pages/offline_pages will implicitly mark whole sections online/offline, so the code really can only handle such granularities. (especially offlining code cannot deal with pageblock_nr_pages but theoretically only MAX_ORDER-1) Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> --- mm/memory_hotplug.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 090cf474de87..30d2fa42b0bb 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -897,6 +897,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ struct memory_notify arg; struct memory_block *mem; + if (!IS_ALIGNED(pfn, PAGES_PER_SECTION)) + return -EINVAL; + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) + return -EINVAL; + /* * We can't use pfn_to_nid() because nid might be stored in struct page * which is not yet initialized. Instead, we find nid from memory block. @@ -1600,10 +1605,9 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) struct zone *zone; struct memory_notify arg; - /* at least, alignment against pageblock is necessary */ - if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) + if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) return -EINVAL; - if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) return -EINVAL; /* This makes hotplug much easier...and readable. we assume this for now. .*/ -- 2.17.1
