From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 617932C9D for ; Thu, 2 Dec 2021 16:56:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23908C00446; Thu, 2 Dec 2021 16:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638464197; bh=0s6SgjQZoecKjBR8OmQ3AwSZx3KbVZTzrj2xll+zbio=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sXPK/G0J0vu1sQwKTPe1d682xXsOYhyf4PEluU7P0mLs8ho67US1FiqdH0CIivcnx Q74BlmiubN8I3Kin6LZxtEA70GT0P6FQP9UOZavdIAHRDPDOLptObIRP5bF7ymQmnh UYlzGvAPwKZmLGWv9kVVdslFhcy4ycSg15iLdn/szFeoMjJOkzHz8ulx41Zjm6CkR+ FdhCWkhpskPbASPNeb7DIDwTH/W2SOeg4s85Q+dAAUlcgy65Hl5n1TIrjDlBmE8gP9 Mmb7enkUUTdbbZ1Ko1x2JVWK4LZ7rkRPUcDHFDmfMvQAqf6QppXUjY7g7e2/sP0b08 9ZgKvA+EivHIA== Date: Thu, 2 Dec 2021 09:56:31 -0700 From: Nathan Chancellor To: Kefeng Wang Cc: Marco Elver , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, llvm@lists.linux.dev Subject: Re: [PATCH v3] arm64: Enable KCSAN Message-ID: References: <20211202143331.15259-1-wangkefeng.wang@huawei.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211202143331.15259-1-wangkefeng.wang@huawei.com> On Thu, Dec 02, 2021 at 10:33:31PM +0800, Kefeng Wang wrote: > 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 I do not think this addition is necessary because we make BTI depend on clang 12 or newer after commit 8cdd23c23c3d ("arm64: Restrict ARM64_BTI_KERNEL to clang 12.0.0 and newer") upstream. I figured it was better to go after the root cause rather than add a bunch of version checks like this to the various sanitizers. > 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 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5F95BC433FE for ; Thu, 2 Dec 2021 16:58:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=KmmFnx10bXUojpAsAO2lyxtIRQkmMDlfIiS9j8NAMCY=; b=L9dt8evAYfP6Dz omgIg7Y5VAROrGSwx6JQCoGYUoSe0Oy2brSdMzPSI6+LfwDEbl2P69w4Q5bq8ta90fSSEhiBNUEaJ eHnsvxduIdo6thhZr5EA6et2vh67ov/OTULEthGQQzE1QLuwXDIQO9fDEcFGlaVTf5PdgjxY6yWDm +N+F2miKSD+mHHNY3ZrYjoRG0/LF/y3JOXRan+4XTo69V6l6tT6gTJUFj41yZlTVPE0FYIj/LwKK4 Mo7X3b9yf1WBWcKMO/fa8b3tAzYU7T/nRPQlbW719GeRv6sbkqW+tPn9eCGySe5ThMROOMQRVEzBj 9yISir9IrYXsPoiGGuYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mspNz-00D5kK-FX; Thu, 02 Dec 2021 16:56:43 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mspNu-00D5jR-Ax for linux-arm-kernel@lists.infradead.org; Thu, 02 Dec 2021 16:56:41 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A32506274F; Thu, 2 Dec 2021 16:56:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23908C00446; Thu, 2 Dec 2021 16:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638464197; bh=0s6SgjQZoecKjBR8OmQ3AwSZx3KbVZTzrj2xll+zbio=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sXPK/G0J0vu1sQwKTPe1d682xXsOYhyf4PEluU7P0mLs8ho67US1FiqdH0CIivcnx Q74BlmiubN8I3Kin6LZxtEA70GT0P6FQP9UOZavdIAHRDPDOLptObIRP5bF7ymQmnh UYlzGvAPwKZmLGWv9kVVdslFhcy4ycSg15iLdn/szFeoMjJOkzHz8ulx41Zjm6CkR+ FdhCWkhpskPbASPNeb7DIDwTH/W2SOeg4s85Q+dAAUlcgy65Hl5n1TIrjDlBmE8gP9 Mmb7enkUUTdbbZ1Ko1x2JVWK4LZ7rkRPUcDHFDmfMvQAqf6QppXUjY7g7e2/sP0b08 9ZgKvA+EivHIA== Date: Thu, 2 Dec 2021 09:56:31 -0700 From: Nathan Chancellor To: Kefeng Wang Cc: Marco Elver , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, llvm@lists.linux.dev Subject: Re: [PATCH v3] arm64: Enable KCSAN Message-ID: References: <20211202143331.15259-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211202143331.15259-1-wangkefeng.wang@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211202_085638_483499_B7103D33 X-CRM114-Status: GOOD ( 26.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Dec 02, 2021 at 10:33:31PM +0800, Kefeng Wang wrote: > 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 I do not think this addition is necessary because we make BTI depend on clang 12 or newer after commit 8cdd23c23c3d ("arm64: Restrict ARM64_BTI_KERNEL to clang 12.0.0 and newer") upstream. I figured it was better to go after the root cause rather than add a bunch of version checks like this to the various sanitizers. > 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 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel