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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 2CB00C282D7 for ; Wed, 30 Jan 2019 16:17:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E69E420870 for ; Wed, 30 Jan 2019 16:17:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731779AbfA3QRF (ORCPT ); Wed, 30 Jan 2019 11:17:05 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:56942 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727546AbfA3QRE (ORCPT ); Wed, 30 Jan 2019 11:17:04 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DBF60EBD; Wed, 30 Jan 2019 08:17:03 -0800 (PST) Received: from [10.1.197.45] (e112298-lin.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5F2F33F589; Wed, 30 Jan 2019 08:17:02 -0800 (PST) Subject: Re: [PATCH v3 0/4] uaccess: Add unsafe accessors for arm64 To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mingo@redhat.com, peterz@infradead.org, hpa@zytor.com Cc: catalin.marinas@arm.com, will.deacon@arm.com, james.morse@arm.com, valentin.schneider@arm.com References: <1547560709-56207-1-git-send-email-julien.thierry@arm.com> From: Julien Thierry Message-ID: <3bb671a6-a7df-9c96-e4d3-09167df6dab1@arm.com> Date: Wed, 30 Jan 2019 16:17:00 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <1547560709-56207-1-git-send-email-julien.thierry@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Gentle ping for patches 3 and 4. Thanks, Julien On 15/01/2019 13:58, Julien Thierry wrote: > Hi, > > First version of this series[1] was briefly in linux-next but had to be > reverted due to a bug where schedule would end up being called while > user_access was active[2]. > > After clarifications[3], rescheduling while in a user_access region is not > allowed. > > * Patches 1 and 2 implement the unsafe accessors for arm64 > * Patches 3 and 4 clarify this restriction in the API and attempts to > check against violations of the restriction. > > Changes since v2[4]: > - Rebase on v5.0-rc2 > - access_ok() is now done in user_access_begin(), so rework accessors > so access_ok() is not called in unsafe_get/put_user() > - Split addition of unsafe accessors and the user_access_region check > into separate patches > - Avoid reading SCTLR_EL1 in user_access_region check > - Add build option for user_access_region checking > - Reword clarifications on unsafe accessors API > > Changes since v1[1]: > - Add a way to detect code calling schedule within a user_access region > - Make sure put_user/get_user arguments are evaluated before disabling PAN > > [1] https://www.spinics.net/lists/arm-kernel/msg674925.html > [2] https://patchwork.kernel.org/patch/10634783/ > [3] https://lkml.org/lkml/2018/11/28/50 > [4] http://lists.infradead.org/pipermail/linux-arm-kernel/2018-December/617080.html > > Cheers, > > Julien > > --> > > Julien Thierry (4): > arm64: uaccess: Cleanup get/put_user() > arm64: uaccess: Implement unsafe accessors > uaccess: Check no rescheduling function is called in unsafe region > arm64: uaccess: Implement user_access_region_active > > arch/arm64/include/asm/sysreg.h | 2 + > arch/arm64/include/asm/uaccess.h | 123 ++++++++++++++++++++++++++------------- > include/linux/kernel.h | 11 +++- > include/linux/uaccess.h | 13 +++++ > kernel/sched/core.c | 22 +++++++ > lib/Kconfig.debug | 8 +++ > 6 files changed, 135 insertions(+), 44 deletions(-) > > -- > 1.9.1 > -- Julien Thierry