diff options
| author | Hugh Dickins <hughd@google.com> | 2014-03-20 21:52:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-03-20 22:09:09 -0700 |
| commit | 7e09e738afd21ef99f047425fc0b0c9be8b03254 (patch) | |
| tree | 423cb848a7d6875509b99720d4afcfa208bac078 /include | |
| parent | 3fb725c48b93c0a152174b6dbbc1029b5e734c7b (diff) | |
mm: fix swapops.h:131 bug if remap_file_pages raced migration
Add remove_linear_migration_ptes_from_nonlinear(), to fix an interesting
little include/linux/swapops.h:131 BUG_ON(!PageLocked) found by trinity:
indicating that remove_migration_ptes() failed to find one of the
migration entries that was temporarily inserted.
The problem comes from remap_file_pages()'s switch from vma_interval_tree
(good for inserting the migration entry) to i_mmap_nonlinear list (no good
for locating it again); but can only be a problem if the remap_file_pages()
range does not cover the whole of the vma (zap_pte() clears the range).
remove_migration_ptes() needs a file_nonlinear method to go down the
i_mmap_nonlinear list, applying linear location to look for migration
entries in those vmas too, just in case there was this race.
The file_nonlinear method does need rmap_walk_control.arg to do this;
but it never needed vma passed in - vma comes from its own iteration.
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rmap.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 1da693d5125..b66c2110cb1 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -250,8 +250,7 @@ struct rmap_walk_control { int (*rmap_one)(struct page *page, struct vm_area_struct *vma, unsigned long addr, void *arg); int (*done)(struct page *page); - int (*file_nonlinear)(struct page *, struct address_space *, - struct vm_area_struct *vma); + int (*file_nonlinear)(struct page *, struct address_space *, void *arg); struct anon_vma *(*anon_lock)(struct page *page); bool (*invalid_vma)(struct vm_area_struct *vma, void *arg); }; |