[v5,06/10] mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone()

Commit Message

David Hildenbrand Oct. 1, 2019, 2:40 p.m. UTC

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 <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Pavel Tatashin <[e-mail]>
Cc: Dan Williams <[e-mail]>
Signed-off-by: David Hildenbrand <[e-mail]>
---
 mm/memory_hotplug.c | 3 +++
 mm/memremap.c       | 2 ++
 2 files changed, 5 insertions(+)

Patch

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 {