mm/memory_hotplug: poison memmap in remove_pfn_range_from_zone()

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.

Link: http://lkml.kernel.org/r/20191006085646.5768-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 36d8091..b2dd94f 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -490,6 +490,9 @@ 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);
+
 #ifdef CONFIG_ZONE_DEVICE
        /*
         * Zone shrinking code cannot properly deal with ZONE_DEVICE. So

diff --git a/mm/memremap.c b/mm/memremap.c
index 4c723d2..09b5b7a 100644 (file)
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -120,6 +120,8 @@ void memunmap_pages(struct dev_pagemap *pgmap)
        nid = page_to_nid(first_page);
 
        mem_hotplug_begin();
+       remove_pfn_range_from_zone(page_zone(first_page), PHYS_PFN(res->start),
+                                  PHYS_PFN(resource_size(res)));
        if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
                __remove_pages(PHYS_PFN(res->start),
                               PHYS_PFN(resource_size(res)), NULL);