Commit a9cd410a3d29 ("mm/page_alloc.c: memory hotplug: free pages as higher
order") assumed that any PFN we get via memory resources is aligned to
to MAX_ORDER - 1, I am not convinced that is always true. Let's play safe,
check the alignment and fallback to single pages.Cc: Arun KS <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Pavel Tatashin <[email protected]> Cc: Dan Williams <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> --- mm/memory_hotplug.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 63b1775f7cf8..f245fb50ba7f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -646,6 +646,9 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, */ for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); + /* __free_pages_core() wants pfns to be aligned to the order */ + if (unlikely(!IS_ALIGNED(pfn, 1ul << order))) + order = 0; (*online_page_callback)(pfn_to_page(pfn), order); } -- 2.21.0
