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 <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> --- mm/memory_hotplug.c | 3 +++ mm/memremap.c | 7 ++++--- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 4da59ec14dbb..5bfca690a922 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 cb90c3e8804a..48f573502f88 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -125,7 +125,7 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) void memunmap_pages(struct dev_pagemap *pgmap) { struct resource *res = &pgmap->res; - unsigned long pfn; + unsigned long pfn = PHYS_PFN(res->start); int nid; dev_pagemap_kill(pgmap); @@ -134,11 +134,12 @@ void memunmap_pages(struct dev_pagemap *pgmap) dev_pagemap_cleanup(pgmap); /* pages are dead and unused, undo the arch mapping */ - nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start))); + nid = page_to_nid(pfn_to_page(pfn)); mem_hotplug_begin(); + remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, + PHYS_PFN(resource_size(res))); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { - pfn = PHYS_PFN(res->start); __remove_pages(pfn, PHYS_PFN(resource_size(res)), NULL); } else { arch_remove_memory(nid, res->start, resource_size(res), -- 2.21.0