Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9073FC433EF for ; Thu, 2 Dec 2021 14:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347244AbhLBO0Z (ORCPT ); Thu, 2 Dec 2021 09:26:25 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:32869 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240661AbhLBO0W (ORCPT ); Thu, 2 Dec 2021 09:26:22 -0500 Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4J4dTQ0nd5zcbmH; Thu, 2 Dec 2021 22:22:50 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 2 Dec 2021 22:22:57 +0800 Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 2 Dec 2021 22:22:57 +0800 From: Kefeng Wang To: Marco Elver , Catalin Marinas , Will Deacon , , CC: , Kefeng Wang Subject: [PATCH v3] arm64: Enable KCSAN Date: Thu, 2 Dec 2021 22:33:31 +0800 Message-ID: <20211202143331.15259-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch enables KCSAN for arm64, with updates to build rules to not use KCSAN for several incompatible compilation units. Resent GCC version(at least GCC10) made outline-atomics as the default option(unlike Clang), which will cause linker errors for kernel/kcsan/core.o. Disables the out-of-line atomics by no-outline-atomics to fix the linker errors. Meanwhile, as Mark said[1], there is a specific issue on arm64 about ARM64_BTI with Clang 11 if KCSAN enabled, which is fixed by Clang 12, add CLANG_VERSION check. And also some latent issues are need to be fixed which isn't just a KCSAN problem, we make the KCSAN depends on EXPERT for now. Tested selftest and kcsan_test(built with GCC11 and Clang 13), and all passed. [1] https://lkml.org/lkml/2021/12/1/354 Signed-off-by: Kefeng Wang --- Tested on Qemu with clang 13 / gcc 11, based on 5.16-rc3. [ 0.221518] kcsan: enabled early [ 0.222422] kcsan: strict mode configured ... [ 5.839223] kcsan: selftest: 3/3 tests passed ... [ 517.895102] # kcsan: pass:24 fail:0 skip:0 total:24 [ 517.896393] # Totals: pass:168 fail:0 skip:0 total:168 [ 517.897502] ok 1 - kcsan v3: - add EXPERT and CLANG_VERSION depends suggested by Mark Rutland v2: - tested on GCC11 and disable outline-atomics for kernel/kcsan/core.c suggested by Marco Elver arch/arm64/Kconfig | 1 + arch/arm64/kernel/vdso/Makefile | 1 + arch/arm64/kvm/hyp/nvhe/Makefile | 1 + kernel/kcsan/Makefile | 1 + 4 files changed, 4 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4ff73299f8a9..3a7b17742cde 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -150,6 +150,7 @@ config ARM64 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) + select HAVE_ARCH_KCSAN if EXPERT && (CC_IS_GCC || CLANG_VERSION >= 120000) select HAVE_ARCH_KFENCE select HAVE_ARCH_KGDB select HAVE_ARCH_MMAP_RND_BITS diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 700767dfd221..60813497a381 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -32,6 +32,7 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS) \ $(CC_FLAGS_LTO) KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y KCOV_INSTRUMENT := n diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index c3c11974fa3b..24b2c2425b38 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -89,6 +89,7 @@ KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI) # cause crashes. Just disable it. GCOV_PROFILE := n KASAN_SANITIZE := n +KCSAN_SANITIZE := n UBSAN_SANITIZE := n KCOV_INSTRUMENT := n diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index c2bb07f5bcc7..e893b0e1d62a 100644 --- a/kernel/kcsan/Makefile +++ b/kernel/kcsan/Makefile @@ -8,6 +8,7 @@ CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \ + $(call cc-option,-mno-outline-atomics) \ -fno-stack-protector -DDISABLE_BRANCH_PROFILING obj-y := core.o debugfs.o report.o -- 2.26.2