Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753223AbdLDQDU (ORCPT ); Mon, 4 Dec 2017 11:03:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33562 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753187AbdLDQDR (ORCPT ); Mon, 4 Dec 2017 11:03:17 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Williams , Jan Kara , Inki Dae , Seung-Woo Kim , Joonyoung Shim , Kyungmin Park , Mauro Carvalho Chehab , Mel Gorman , Vlastimil Babka , Christoph Hellwig , Doug Ledford , Hal Rosenstock , Jason Gunthorpe , Jeff Moyer , Ross Zwisler , Sean Hefty , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 10/95] mm: fail get_vaddr_frames() for filesystem-dax mappings Date: Mon, 4 Dec 2017 16:59:34 +0100 Message-Id: <20171204160046.606167539@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171204160046.206920966@linuxfoundation.org> References: <20171204160046.206920966@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2353 Lines: 63 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams commit b7f0554a56f21fb3e636a627450a9add030889be upstream. Until there is a solution to the dma-to-dax vs truncate problem it is not safe to allow V4L2, Exynos, and other frame vector users to create long standing / irrevocable memory registrations against filesytem-dax vmas. [dan.j.williams@intel.com: add comment for vma_is_fsdax() check in get_vaddr_frames(), per Jan] Link: http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.stgit@dwillia2-desk3.amr.corp.intel.com Link: http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Dan Williams Reviewed-by: Jan Kara Cc: Inki Dae Cc: Seung-Woo Kim Cc: Joonyoung Shim Cc: Kyungmin Park Cc: Mauro Carvalho Chehab Cc: Mel Gorman Cc: Vlastimil Babka Cc: Christoph Hellwig Cc: Doug Ledford Cc: Hal Rosenstock Cc: Jason Gunthorpe Cc: Jeff Moyer Cc: Ross Zwisler Cc: Sean Hefty Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/frame_vector.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -53,6 +53,18 @@ int get_vaddr_frames(unsigned long start ret = -EFAULT; goto out; } + + /* + * While get_vaddr_frames() could be used for transient (kernel + * controlled lifetime) pinning of memory pages all current + * users establish long term (userspace controlled lifetime) + * page pinning. Treat get_vaddr_frames() like + * get_user_pages_longterm() and disallow it for filesystem-dax + * mappings. + */ + if (vma_is_fsdax(vma)) + return -EOPNOTSUPP; + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false;