diff options
| author | Hugh Dickins <hughd@google.com> | 2021-06-24 18:39:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-24 19:40:53 -0700 |
| commit | 448282487483d6fa5b2eeeafaa0acc681e544a9c (patch) | |
| tree | 23097bf7a0c1de1b5ce8e8035cf11365e78d32c5 | |
| parent | e2e1d4076c77b3671cf8ce702535ae7dee3acf89 (diff) | |
| download | lwn-448282487483d6fa5b2eeeafaa0acc681e544a9c.tar.gz lwn-448282487483d6fa5b2eeeafaa0acc681e544a9c.zip | |
mm: page_vma_mapped_walk(): crossing page table boundary
page_vma_mapped_walk() cleanup: adjust the test for crossing page table
boundary - I believe pvmw->address is always page-aligned, but nothing
else here assumed that; and remember to reset pvmw->pte to NULL after
unmapping the page table, though I never saw any bug from that.
Link: https://lkml.kernel.org/r/799b3f9c-2a9e-dfef-5d89-26e9f76fd97@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/page_vma_mapped.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 261fc929b08d..9c87b3090a1b 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -244,16 +244,16 @@ next_pte: if (pvmw->address >= end) return not_found(pvmw); /* Did we cross page table boundary? */ - if (pvmw->address % PMD_SIZE == 0) { - pte_unmap(pvmw->pte); + if ((pvmw->address & (PMD_SIZE - PAGE_SIZE)) == 0) { if (pvmw->ptl) { spin_unlock(pvmw->ptl); pvmw->ptl = NULL; } + pte_unmap(pvmw->pte); + pvmw->pte = NULL; goto restart; - } else { - pvmw->pte++; } + pvmw->pte++; } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) { |