The patch titled Subject: mm/memory_hotplug: make sure the pfn is aligned to the order when onlining has been removed from the -mm tree. Its filename was mm-memory_hotplug-make-sure-the-pfn-is-aligned-to-the-order-when-onlining.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm/memory_hotplug: make sure the pfn is aligned to the order when onlining 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. akpm: warn in this situation so we get to find out if and why this ever occurs. [akpm@xxxxxxxxxxxxxxxxxxxx: add WARN_ON_ONCE()] Link: http://lkml.kernel.org/r/20190814154109.3448-5-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Arun KS <arunks@xxxxxxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Nadav Amit <namit@xxxxxxxxxx> Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/memory_hotplug.c~mm-memory_hotplug-make-sure-the-pfn-is-aligned-to-the-order-when-onlining +++ a/mm/memory_hotplug.c @@ -646,6 +646,9 @@ static int online_pages_range(unsigned l */ 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 (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) + order = 0; (*online_page_callback)(pfn_to_page(pfn), order); } _ Patches currently in -mm which might be from david@xxxxxxxxxx are