| commit | f0fed8283deb13d36ff8285f4c93bd012dae554d | [log] [tgz] |
|---|---|---|
| author | Ralph Campbell <[email protected]> | Tue Aug 13 15:37:11 2019 -0700 |
| committer | Greg Kroah-Hartman <[email protected]> | Sun Aug 25 10:47:43 2019 +0200 |
| tree | 6087c39600c63bffb0265fc7e9805e15892f6d25 | |
| parent | 3858cca150c69ea8dbc1f1b03fd444d99fb747b7 [diff] |
mm/hmm: fix bad subpage pointer in try_to_unmap_one commit 1de13ee59225dfc98d483f8cce7d83f97c0b31de upstream. When migrating an anonymous private page to a ZONE_DEVICE private page, the source page->mapping and page->index fields are copied to the destination ZONE_DEVICE struct page and the page_mapcount() is increased. This is so rmap_walk() can be used to unmap and migrate the page back to system memory. However, try_to_unmap_one() computes the subpage pointer from a swap pte which computes an invalid page pointer and a kernel panic results such as: BUG: unable to handle page fault for address: ffffea1fffffffc8 Currently, only single pages can be migrated to device private memory so no subpage computation is needed and it can be set to "page". [[email protected]: add comment] Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Fixes: a5430dda8a3a1c ("mm/migrate: support un-addressable ZONE_DEVICE page in migration") Signed-off-by: Ralph Campbell <[email protected]> Cc: "Jérôme Glisse" <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: John Hubbard <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Ira Weiny <[email protected]> Cc: Jan Kara <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Logan Gunthorpe <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>