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=ham 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 5E5C0C31E47 for ; Wed, 12 Jun 2019 14:33:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2344C2082C for ; Wed, 12 Jun 2019 14:33:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2344C2082C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C5BEB6B000D; Wed, 12 Jun 2019 10:33:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BE5286B000E; Wed, 12 Jun 2019 10:33:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A85126B0010; Wed, 12 Jun 2019 10:33:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by kanga.kvack.org (Postfix) with ESMTP id 5A7B36B000D for ; Wed, 12 Jun 2019 10:33:47 -0400 (EDT) Received: by mail-ed1-f69.google.com with SMTP id k22so26209272ede.0 for ; Wed, 12 Jun 2019 07:33:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:to:cc :references:from:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=eQY+hXskG9MfrsSCk8NQ023zNMoKAQxNRyn6p8EG3ks=; b=K6LHxdsIhd1L59svH32c+SNI75RLCbyeSRs/4YtKQNIWBo73brNDvy1qttcGO8bK81 3CKMMhXvRqNQnRRiYRuhwekOItHXvP5r81ptN/S3favvyXp0UfK7eZFFILtgLc3CNttH hTOm+cWzViLeuPaT5Je4PK7K+HHQk0xSdWIr/VKFYaTFkx7Z/i4WVn33auoqFiS9Tbur Qw4OOLtk460DrA6hiCshbGjAnulKSmM0pZa6QEffyiuaFt8TpastgeU3PtUMlfxdX0vs g3aFGEz5yYBO3DyuBwqd73ygH6IXyNEt/GkqaK1ZcpfpZw1lUv6ACkI7GAKeX7XWmqSy 4v3Q== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of vincenzo.frascino@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=vincenzo.frascino@arm.com X-Gm-Message-State: APjAAAXrj1MRcl+CukGuEzT0VvGr8rWya63aTuAki8pMICpfcsw+av/i w1QsCMNe+7O0edyQT3Lx7yMUmvZAc3AHkY7CvOCm5o40VYIPZEdQQ7YaGjAiqULqg6dK4VmQFCi QZw/Qe9NSjoW6l6BTYXYYTomWbEXIShtAqlHKWmMdavbfF5gwPnp9/h+D2Je5Mdj6uA== X-Received: by 2002:a50:cb04:: with SMTP id g4mr76723977edi.181.1560350026926; Wed, 12 Jun 2019 07:33:46 -0700 (PDT) X-Google-Smtp-Source: APXvYqyXdG5LaJJ84QML2Wl4qhPK3Zks2K2S9cPuYUXuNvADnQTQNBgh9lxwW2wxBgAr6Kl+8/x6 X-Received: by 2002:a50:cb04:: with SMTP id g4mr76723900edi.181.1560350026235; Wed, 12 Jun 2019 07:33:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1560350026; cv=none; d=google.com; s=arc-20160816; b=IybslSAMfi1CAkAH68musSpGzeOhH1BBDDjaqycBKIN2w3WVXe4HNhmNRt7UHdH6NO NKbXDKD+/1dXI4U8sH+91x77se8/iUPw/gPoMEc/ZSAjG650x0X/qqrHoIh3HIJujBxv EeqOrg8zEN3cMq/JENeUp2+ExCvluocXdMzksDOddPnBeQlsfUeGW8akmBranaDem9oh Xbv9y2teB4jKxdlb0GT74gSgI/h4B7a1LvPvFvNKlSNwi7GBF1bvd7nRZm6FHKBdwsp+ o6InG3Iy/+jGeCoHEVZIKfGOMcnnjSz+V/VK+j2UhQNQjBTH7CB07HKNlDh2L+X6Xdsu d8hQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject; bh=eQY+hXskG9MfrsSCk8NQ023zNMoKAQxNRyn6p8EG3ks=; b=Do6NTxaPeaoMrw7ydkgrg5/bWGXtRkueFby4eNCsAQlCHMRDIEK7rpSp8CWhUFIg/S i58e7uIk2F4l3WN/hcgGwmtznvgZJ2YD2CdBqiQ8AVyZA55GKkeCX+iTHP2csCvgyBBt iHC+ur+BrGKHoSQsbuUDCPCcfiWge1dtrUfMECcaHYWhD1H/sPJDEfxzZKS2dWpHj7UO Z+IrpxjCo63m8NwVImr1dyd95bQdVYwuTId/2uxojxR/TWC+MiwoiQEpW5hbi87kT4gs 70EJUm4Z3Djmj3YxVIfi6aqx3DPLmp2ivOWGM5NFwBs0jwkc8IVIfIbEDM6JUnHjGF/S dGCw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of vincenzo.frascino@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=vincenzo.frascino@arm.com Received: from foss.arm.com (foss.arm.com. [217.140.110.172]) by mx.google.com with ESMTP id a14si72555ejr.135.2019.06.12.07.33.45 for ; Wed, 12 Jun 2019 07:33:46 -0700 (PDT) Received-SPF: pass (google.com: domain of vincenzo.frascino@arm.com designates 217.140.110.172 as permitted sender) client-ip=217.140.110.172; Authentication-Results: mx.google.com; spf=pass (google.com: domain of vincenzo.frascino@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=vincenzo.frascino@arm.com 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 38A462B; Wed, 12 Jun 2019 07:33:45 -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 C1F953F557; Wed, 12 Jun 2019 07:33:39 -0700 (PDT) Subject: Re: [PATCH v17 05/15] mm, arm64: untag user pointers in mm/gup.c 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: <8f65548bef8544d49980a92d221b74440d544c1e.1560339705.git.andreyknvl@google.com> From: Vincenzo Frascino Message-ID: <8b74a24e-4fe0-3fdd-e66a-d04c359b6104@arm.com> Date: Wed, 12 Jun 2019 15:33:38 +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: <8f65548bef8544d49980a92d221b74440d544c1e.1560339705.git.andreyknvl@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. > > 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: Kees Cook > Reviewed-by: Catalin Marinas > Signed-off-by: Andrey Konovalov Reviewed-by: Vincenzo Frascino > --- > mm/gup.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/gup.c b/mm/gup.c > index ddde097cf9e4..c37df3d455a2 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -802,6 +802,8 @@ 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)); > > /* > @@ -964,6 +966,8 @@ 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; > > -- Regards, Vincenzo