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authorHugh Dickins <hughd@google.com>2021-06-25 04:39:14 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-25 05:40:53 +0300
commit448282487483d6fa5b2eeeafaa0acc681e544a9c (patch)
tree23097bf7a0c1de1b5ce8e8035cf11365e78d32c5
parente2e1d4076c77b3671cf8ce702535ae7dee3acf89 (diff)
downloadlinux-448282487483d6fa5b2eeeafaa0acc681e544a9c.tar.xz
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.c8
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) {