Commit 48db54ee authored Feb 01, 2011 by Minchan Kim Committed by Linus Torvalds Feb 02, 2011

mm/migration: fix page corruption during hugepage migration



If migrate_huge_page by memory-failure fails , it calls put_page in itself
to decrease page reference and caller of migrate_huge_page also calls
putback_lru_pages.  It can do double free of page so it can make page
corruption on page holder.

In addtion, clean of pages on caller is consistent behavior with
migrate_pages by cf608ac1 ("mm: compaction: fix COMPACTPAGEFAILED
counting").

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 57fc4a5e

mm/memory-failure.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -1295,7 +1295,10 @@ static int soft_offline_huge_page(struct page *page, int flags)
		ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0,
		true);
		if (ret) {
		putback_lru_pages(&pagelist);
		struct page page1, page2;
		list_for_each_entry_safe(page1, page2, &pagelist, lru)
		put_page(page1);

		pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
		pfn, ret, page->flags);
		if (ret > 0)

mm/migrate.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -980,10 +980,6 @@ int migrate_huge_pages(struct list_head *from,
		}
		rc = 0;
		out:

		list_for_each_entry_safe(page, page2, from, lru)
		put_page(page);

		if (rc)
		return rc;

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