From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00A96C31E48 for ; Wed, 12 Jun 2019 14:34:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D98C62082C for ; Wed, 12 Jun 2019 14:34:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731851AbfFLOej (ORCPT ); Wed, 12 Jun 2019 10:34:39 -0400 Received: from foss.arm.com ([217.140.110.172]:54596 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726840AbfFLOej (ORCPT ); Wed, 12 Jun 2019 10:34:39 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 74C632B; Wed, 12 Jun 2019 07:34:38 -0700 (PDT) Received: from [10.1.196.72] (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D68633F557; Wed, 12 Jun 2019 07:34:32 -0700 (PDT) Subject: Re: [PATCH v17 06/15] mm, arm64: untag user pointers in get_vaddr_frames To: Andrey Konovalov , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Kevin Brodsky , Szabolcs Nagy References: <4c0b9a258e794437a1c6cec97585b4b5bd2d3bba.1560339705.git.andreyknvl@google.com> From: Vincenzo Frascino Message-ID: <89b0c166-9a83-ba09-42e1-4fa478417b3d@arm.com> Date: Wed, 12 Jun 2019 15:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <4c0b9a258e794437a1c6cec97585b4b5bd2d3bba.1560339705.git.andreyknvl@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Archived-At: List-Archive: List-Post: On 12/06/2019 12:43, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > get_vaddr_frames uses provided user pointers for vma lookups, which can > only by done with untagged pointers. Instead of locating and changing > all callers of this function, perform untagging in it. > > Acked-by: Catalin Marinas > Reviewed-by: Kees Cook > Signed-off-by: Andrey Konovalov Reviewed-by: Vincenzo Frascino > --- > mm/frame_vector.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/frame_vector.c b/mm/frame_vector.c > index c64dca6e27c2..c431ca81dad5 100644 > --- a/mm/frame_vector.c > +++ b/mm/frame_vector.c > @@ -46,6 +46,8 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > if (WARN_ON_ONCE(nr_frames > vec->nr_allocated)) > nr_frames = vec->nr_allocated; > > + start = untagged_addr(start); > + > down_read(&mm->mmap_sem); > locked = 1; > vma = find_vma_intersection(mm, start, start + 1); > -- Regards, Vincenzo