diff options
| author | Hugh Dickins <hughd@google.com> | 2021-07-07 13:11:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-11 15:05:15 -0700 |
| commit | 023e1a8dd502405ba378a7fbb1ce62beb0616708 (patch) | |
| tree | a460bbc7478c15f8cea3366785ad91607d0529fc /mm | |
| parent | d9770fcc1c0c5b3e77dfac83b47defa3981fa7cd (diff) | |
| download | linux-023e1a8dd502405ba378a7fbb1ce62beb0616708.tar.bz2 | |
mm/rmap: fix new bug: premature return from page_mlock_one()
In the unlikely race case that page_mlock_one() finds VM_LOCKED has been
cleared by the time it got page table lock, page_vma_mapped_walk_done()
must be called before returning, either explicitly, or by a final call
to page_vma_mapped_walk() - otherwise the page table remains locked.
Fixes: cd62734ca60d ("mm/rmap: split try_to_munlock from try_to_unmap")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/20210711151446.GB4070@xsang-OptiPlex-9020/
Link: https://lore.kernel.org/lkml/f71f8523-cba7-3342-40a7-114abc5d1f51@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/rmap.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 0e83c3be8568..1235368f0628 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1990,14 +1990,13 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma, * this function is never called when PageDoubleMap(). */ mlock_vma_page(page); + /* + * No need to scan further once the page is marked + * as mlocked. + */ page_vma_mapped_walk_done(&pvmw); + return false; } - - /* - * no need to continue scanning other vma's if the page has - * been locked. - */ - return false; } return true; |