From: Miaohe Lin linmiaohe@huawei.com
[ Upstream commit 5d5d19eda6b0ee790af89c45e3f678345be6f50f ]
For PMD-mapped page (usually THP), pvmw->pte is NULL. For PTE-mapped THP, pvmw->pte is mapped. But for HugeTLB pages, pvmw->pte is not mapped and set to the relevant page table entry. So in page_vma_mapped_walk_done(), we may do pte_unmap() for HugeTLB pte which is not mapped. Fix this by checking pvmw->page against PageHuge before trying to do pte_unmap().
Link: https://lkml.kernel.org/r/20210127093349.39081-1-linmiaohe@huawei.com Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hongxiang Lou louhongxiang@huawei.com Signed-off-by: Miaohe Lin linmiaohe@huawei.com Tested-by: Sedat Dilek sedat.dilek@gmail.com Cc: Kees Cook keescook@chromium.org Cc: Nathan Chancellor natechancellor@gmail.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Shakeel Butt shakeelb@google.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Vlastimil Babka vbabka@suse.cz Cc: Michel Lespinasse walken@google.com Cc: Nick Desaulniers ndesaulniers@google.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Wei Yang richard.weiyang@linux.alibaba.com Cc: Dmitry Safonov 0x7f454c46@gmail.com Cc: Brian Geffon bgeffon@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/rmap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 70085ca1a3fc9..def5c62c93b3b 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -213,7 +213,8 @@ struct page_vma_mapped_walk {
static inline void page_vma_mapped_walk_done(struct page_vma_mapped_walk *pvmw) { - if (pvmw->pte) + /* HugeTLB pte is set to the relevant page table entry without pte_mapped. */ + if (pvmw->pte && !PageHuge(pvmw->page)) pte_unmap(pvmw->pte); if (pvmw->ptl) spin_unlock(pvmw->ptl);