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=-17.4 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_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 953B0C76186 for ; Tue, 23 Jul 2019 18:00:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6FEB22239E for ; Tue, 23 Jul 2019 18:00:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="XwZfpnbX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727892AbfGWSAr (ORCPT ); Tue, 23 Jul 2019 14:00:47 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:47245 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391252AbfGWR7X (ORCPT ); Tue, 23 Jul 2019 13:59:23 -0400 Received: by mail-qt1-f202.google.com with SMTP id s9so39164874qtn.14 for ; Tue, 23 Jul 2019 10:59:22 -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=4Wn1GFyfxt3NCYf4PGNTFvqYM1MN1tNvgEFxNqktnk8=; b=XwZfpnbXFN1ibF12kJh4UX27GKqgHpAYVMgncvRg2XMsGuyHBAM2BbcbV2FMLG6KI2 Eail8AtVvVEkdWyRNAKDAPdYJBEXOQRcSGAF4Z+pO2ORJP6spfMGKAIf7M0K0GlZ5J+x 8yVEMOwDv+oyp2b+30vvjnV2SNVEvVcKU1T+4yjg+W1ok7J01teWzQ68jS7jmU8ro/kC Oxn9FlCYKBVtK3Jwi5MWr/zhUNuljezL1OPreJbqbiZZtnxrZ1CQ3LvL2shMV2iJ2vVT olnzEJp2mTvJs0fngbdCdc/sbDwJUI9/28M468SMn/xpTOjrRZ2LIWF7gDkmDS+GMcl9 Q1sg== 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=4Wn1GFyfxt3NCYf4PGNTFvqYM1MN1tNvgEFxNqktnk8=; b=K0EpHiwBkRsX9KIQ7+EbMFaPEMSvzoe2oG7HEshgbIfXnYbU+/kkYxaghOSRirVzoQ kA2uwLXFAZldM8pZk+LfZJ/y5nTCro9TSRkB7PrzSEc+Hvx686E1vAlK4soLw8V7/qRJ 2d7p7dTcBWdDwa2Ats43G6m8a3FdnfqBA3Mc8+pycpRyGY6vZU2ZcpXuJR9CEBPTh0rs hFj7eI0FZ4cK/gD2Sjmd1DXODZWPi1gns+OJpvfQXNJ9OK90S/F4/D6R+/p/HiTl0lhK hJOz3IYOe01DULMtsVkPuARF7uGl8E4RAsmkWGisb1QD9x/8tR14E9dZjlo7tC35V6vt vPzw== X-Gm-Message-State: APjAAAWLbWDC3sjg+yRiCRWaQlcL6mNsh289Xzi+vAYxMyIVz4l08E0J dwJgDocXjQtxCQ/LeazZdepnpx42FagelLbo X-Google-Smtp-Source: APXvYqy0Hkccu8SUSwSAcf0RwepBseg9rSnBcrNaRpXVNhE8d6jRb6uSi4vWmbN3MkxTqVVfEdk8tSl4b+EbX0xe X-Received: by 2002:a37:4f47:: with SMTP id d68mr50765232qkb.104.1563904762211; Tue, 23 Jul 2019 10:59:22 -0700 (PDT) Date: Tue, 23 Jul 2019 19:58:42 +0200 In-Reply-To: Message-Id: <4731bddba3c938658c10ff4ed55cc01c60f4c8f8.1563904656.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v19 05/15] mm: 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 , 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 , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This patch is a part of a series that extends 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. Reviewed-by: Khalid Aziz Reviewed-by: Vincenzo Frascino Reviewed-by: Kees Cook Reviewed-by: Catalin Marinas 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 98f13ab37bac..1c1c97ec63df 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -799,6 +799,8 @@ 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)); /* @@ -961,6 +963,8 @@ 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; -- 2.22.0.709.g102302147b-goog