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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 9AB1EC43219 for ; Tue, 30 Apr 2019 13:27:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68DB92075E for ; Tue, 30 Apr 2019 13:27:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="MSiPsDRD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728846AbfD3N1d (ORCPT ); Tue, 30 Apr 2019 09:27:33 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:42310 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728320AbfD3NZk (ORCPT ); Tue, 30 Apr 2019 09:25:40 -0400 Received: by mail-qt1-f201.google.com with SMTP id c44so13462871qtb.9 for ; Tue, 30 Apr 2019 06:25:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=buRPOjJBA3ZIe0xT2AqduI9dnmEg9opX2ORFfRDPnW0=; b=MSiPsDRD20G5RApt1tKO2qR1lu+49IUxbNva1JnuQQuFWBLmYjGsyYMIbTfczh9PgZ LZDjXLLUSTuHLQNcWT+JZ9uqhm42MotSkIywGhSEtO5Qo/efiUjRdnETJ9HiPnIEMC0G Psfny8eMA3Hhr5M3y/dGxBagnarVCzNzCOPBE7unSjVZRyN7RZGPxN+EiQrIg6TYKayd TbH8puePOyzHgUDHu0r16X0QIZiy8sIilI5NkVuEFwagLhwm1Doy6sj5Nc20vSi1QEC6 U4ZuKp24KxWFzfXdfPQJckkIwH9zeR4BqyMjbNu7gnM8XYqQKJF/hqcaAUToZRnS5F/8 +rFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=buRPOjJBA3ZIe0xT2AqduI9dnmEg9opX2ORFfRDPnW0=; b=RBEr/+VpXBiCJ8bWvy66i7rg4UMdPmvGVDclj9olkMcVt/OENCG9ZSZTw2PBuNLjnW xmu4XR1udCpaBXmurh83eOW6LNJWNt/la041KXX7r2W/R95ndaugii7nmidkLFRsvXdy jRhXDtkeuobokHeder2RxXV+VzfGCxMxtuOE9/eg0cF2/Y1W+JUHgfcZv70nrpP5N8iS 0Xsnoc5Cbnebq0ppaFDfosACazX9il5Zs0/Lj9dmEy221uMAJFFBYk2st+zEdmBhLN5m 1LAOVkx5U8BumMcFmabQXm9caA0DorGvRdq3+9lRuyU9UCzpTGUgxYRVxJH6TYqRXnRN +yKQ== X-Gm-Message-State: APjAAAX5VMLBbZrCZ9jwyljq8lelzmc5fci1DUY3ANxqnbfJO/QB+7hx fVztMl2t6rJEXsZI48XeydT+MvU7LRtWItJt X-Google-Smtp-Source: APXvYqzAjOcf9MQ3Z/Pp48cxI+z95y8oMsVd6n1et+BqzlTkjxro8PcOOzrVkSjDVN6zaY8gkVAdj4JwROetfHnZ X-Received: by 2002:a37:78f:: with SMTP id 137mr13240464qkh.66.1556630738975; Tue, 30 Apr 2019 06:25:38 -0700 (PDT) Date: Tue, 30 Apr 2019 15:25:03 +0200 In-Reply-To: Message-Id: <373d33e4cb0087da32ad019fd212414292ce04c8.1556630205.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH v14 07/17] mm, arm64: untag user pointers in mm/gup.c From: Andrey Konovalov To: 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 , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Kuehling@google.com, Felix , Deucher@google.com, Alexander , Koenig@google.com, Christian , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. mm/gup.c provides a kernel interface that accepts user addresses and manipulates user pages directly (for example get_user_pages, that is used by the futex syscall). Since a user can provided tagged addresses, we need to handle this case. Add untagging to gup.c functions that use user addresses for vma lookups. Signed-off-by: Andrey Konovalov --- mm/gup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index 91819b8ad9cc..2f477a0a7180 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -696,6 +696,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (!nr_pages) return 0; + start = untagged_addr(start); + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); /* @@ -858,6 +860,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct *vma; vm_fault_t ret, major = 0; + address = untagged_addr(address); + if (unlocked) fault_flags |= FAULT_FLAG_ALLOW_RETRY; -- 2.21.0.593.g511ec345e18-goog