From: Jue Wang juew@google.com Subject: mm/thp: fix page_address_in_vma() on file THP tails
Anon THP tails were already supported, but memory-failure may need to use page_address_in_vma() on file THP tails, which its page->mapping check did not permit: fix it.
hughd adds: no current usage is known to hit the issue, but this does fix a subtle trap in a general helper: best fixed in stable sooner than later.
Link: https://lkml.kernel.org/r/a0d9b53-bf5d-8bab-ac5-759dc61819c1@google.com Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Signed-off-by: Jue Wang juew@google.com Signed-off-by: Hugh Dickins hughd@google.com Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Reviewed-by: Yang Shi shy828301@gmail.com Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: Alistair Popple apopple@nvidia.com Cc: Jan Kara jack@suse.cz Cc: Miaohe Lin linmiaohe@huawei.com Cc: Minchan Kim minchan@kernel.org Cc: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Oscar Salvador osalvador@suse.de Cc: Peter Xu peterx@redhat.com Cc: Ralph Campbell rcampbell@nvidia.com Cc: Shakeel Butt shakeelb@google.com Cc: Wang Yugui wangyugui@e16-tech.com Cc: Zi Yan ziy@nvidia.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/rmap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/mm/rmap.c~mm-thp-fix-page_address_in_vma-on-file-thp-tails +++ a/mm/rmap.c @@ -716,11 +716,11 @@ unsigned long page_address_in_vma(struct if (!vma->anon_vma || !page__anon_vma || vma->anon_vma->root != page__anon_vma->root) return -EFAULT; - } else if (page->mapping) { - if (!vma->vm_file || vma->vm_file->f_mapping != page->mapping) - return -EFAULT; - } else + } else if (!vma->vm_file) { + return -EFAULT; + } else if (vma->vm_file->f_mapping != compound_head(page)->mapping) { return -EFAULT; + }
return vma_address(page, vma); } _