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=-15.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 0AC8AC433E0 for ; Fri, 5 Feb 2021 19:54:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB7FA64FBA for ; Fri, 5 Feb 2021 19:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233226AbhBESLq (ORCPT ); Fri, 5 Feb 2021 13:11:46 -0500 Received: from foss.arm.com ([217.140.110.172]:36748 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233109AbhBEPU3 (ORCPT ); Fri, 5 Feb 2021 10:20:29 -0500 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 081A9106F; Fri, 5 Feb 2021 08:54:43 -0800 (PST) Received: from [10.37.8.15] (unknown [10.37.8.15]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3202E3F718; Fri, 5 Feb 2021 08:54:41 -0800 (PST) Subject: Re: [PATCH v11 0/5] arm64: ARMv8.5-A: MTE: Add async mode support To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Cc: Andrew Morton , Catalin Marinas , Will Deacon , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Branislav Rankov , Andrey Konovalov References: <20210130165225.54047-1-vincenzo.frascino@arm.com> From: Vincenzo Frascino Message-ID: <1477c6da-a0fe-903c-4257-84c45908c836@arm.com> Date: Fri, 5 Feb 2021 16:58:42 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210130165225.54047-1-vincenzo.frascino@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/30/21 4:52 PM, Vincenzo Frascino wrote: > This patchset implements the asynchronous mode support for ARMv8.5-A > Memory Tagging Extension (MTE), which is a debugging feature that allows > to detect with the help of the architecture the C and C++ programmatic > memory errors like buffer overflow, use-after-free, use-after-return, etc. > > MTE is built on top of the AArch64 v8.0 virtual address tagging TBI > (Top Byte Ignore) feature and allows a task to set a 4 bit tag on any > subset of its address space that is multiple of a 16 bytes granule. MTE > is based on a lock-key mechanism where the lock is the tag associated to > the physical memory and the key is the tag associated to the virtual > address. > When MTE is enabled and tags are set for ranges of address space of a task, > the PE will compare the tag related to the physical memory with the tag > related to the virtual address (tag check operation). Access to the memory > is granted only if the two tags match. In case of mismatch the PE will raise > an exception. > > The exception can be handled synchronously or asynchronously. When the > asynchronous mode is enabled: > - Upon fault the PE updates the TFSR_EL1 register. > - The kernel detects the change during one of the following: > - Context switching > - Return to user/EL0 > - Kernel entry from EL1 > - Kernel exit to EL1 > - If the register has been updated by the PE the kernel clears it and > reports the error. > > The series is based on linux-next/akpm. > We are suspecting an issue with with the kernel access nofault functions triggering async faults that impacts Android init process. Please do not merge this series until this is sorted. > To simplify the testing a tree with the new patches on top has been made > available at [1]. > > [1] https://git.gitlab.arm.com/linux-arm/linux-vf.git mte/v10.async.akpm > > Changes: > -------- > v11: > - Added patch that disables KUNIT tests in async mode > v10: > - Rebase on the latest linux-next/akpm > - Address review comments. > v9: > - Rebase on the latest linux-next/akpm > - Address review comments. > v8: > - Address review comments. > v7: > - Fix a warning reported by kernel test robot. This > time for real. > v6: > - Drop patches that forbid KASAN KUNIT tests when async > mode is enabled. > - Fix a warning reported by kernel test robot. > - Address review comments. > v5: > - Rebase the series on linux-next/akpm. > - Forbid execution for KASAN KUNIT tests when async > mode is enabled. > - Dropped patch to inline mte_assign_mem_tag_range(). > - Address review comments. > v4: > - Added support for kasan.mode (sync/async) kernel > command line parameter. > - Addressed review comments. > v3: > - Exposed kasan_hw_tags_mode to convert the internal > KASAN represenetation. > - Added dsb() for kernel exit paths in arm64. > - Addressed review comments. > v2: > - Fixed a compilation issue reported by krobot. > - General cleanup. > > Cc: Andrew Morton > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Dmitry Vyukov > Cc: Andrey Ryabinin > Cc: Alexander Potapenko > Cc: Marco Elver > Cc: Evgenii Stepanov > Cc: Branislav Rankov > Cc: Andrey Konovalov > Signed-off-by: Vincenzo Frascino > > Andrey Konovalov (1): > kasan: don't run tests in async mode > > Vincenzo Frascino (4): > arm64: mte: Add asynchronous mode support > kasan: Add KASAN mode kernel parameter > kasan: Add report for async mode > arm64: mte: Enable async tag check fault > > Documentation/dev-tools/kasan.rst | 9 +++++ > arch/arm64/include/asm/memory.h | 3 +- > arch/arm64/include/asm/mte-kasan.h | 9 ++++- > arch/arm64/include/asm/mte.h | 32 ++++++++++++++++ > arch/arm64/kernel/entry-common.c | 6 +++ > arch/arm64/kernel/mte.c | 60 +++++++++++++++++++++++++++++- > include/linux/kasan.h | 6 +++ > lib/test_kasan.c | 6 ++- > mm/kasan/hw_tags.c | 51 ++++++++++++++++++++++++- > mm/kasan/kasan.h | 7 +++- > mm/kasan/report.c | 17 ++++++++- > 11 files changed, 196 insertions(+), 10 deletions(-) > -- Regards, Vincenzo