Let's poison the pages similar to when adding new memory in sparse_add_section(). Also call remove_pfn_range_from_zone() from memunmap_pages(), so we can poison the memmap from there as well.
While at it, calculate the pfn in memunmap_pages() only once. Cc: Andrew Morton <[email protected]> Cc: David Hildenbrand <[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 +++ mm/memremap.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index cef909ebd807..640309236a58 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -464,6 +464,9 @@ void __ref remove_pfn_range_from_zone(struct zone *zone, struct pglist_data *pgdat = zone->zone_pgdat; unsigned long flags; + /* Poison struct pages because they are now uninitialized again. */ + page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); + /* * Zone shrinking code cannot properly deal with ZONE_DEVICE. So * we will not try to shrink the zones - which is okay as diff --git a/mm/memremap.c b/mm/memremap.c index 734afeaad811..371939f92b69 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -139,6 +139,8 @@ void memunmap_pages(struct dev_pagemap *pgmap) nid = page_to_nid(pfn_to_page(start_pfn)); mem_hotplug_begin(); + remove_pfn_range_from_zone(page_zone(pfn_to_page(start_pfn)), + start_pfn, nr_pages); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { __remove_pages(start_pfn, nr_pages, NULL); } else { -- 2.21.0

