From patchwork Mon Nov 4 14:27:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marco Elver X-Patchwork-Id: 11225941 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7AA3A1390 for ; Mon, 4 Nov 2019 14:29:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4666121D7F for ; Mon, 4 Nov 2019 14:29:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="RwMp4ufZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729142AbfKDO3X (ORCPT ); Mon, 4 Nov 2019 09:29:23 -0500 Received: from mail-wr1-f73.google.com ([209.85.221.73]:48707 "EHLO mail-wr1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729061AbfKDO3X (ORCPT ); Mon, 4 Nov 2019 09:29:23 -0500 Received: by mail-wr1-f73.google.com with SMTP id h4so10497476wrx.15 for ; Mon, 04 Nov 2019 06:29:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=v/fBCawgbNr9z8sHoDyBwn+JenP5278dLuCFcze5nO4=; b=RwMp4ufZMoAcy8AGYLyDxOiK52Y41IM5Omu5uyT1UQikQpowYCEdcb8GrcK71T8g5n C72pggEFwJnmMPerjWv2sTnaV6/S5Yd6Y6O00gERNelbkaBI9N2T1+v4C2nXgYBwo5Rj QaDlbklupShqTrgcnZ2WP6nCfyuM5+zjFaSApzBrMx6qoIMrnUFWntuH2puHKq0HJJhx ofz5Vh2ubSbi72M1x6K6RQiUV4mBMZQYHRvQ7sYWm7ATdo4nulInqcTv+r6ITZ0cQblc IS7EkLHNU3eGauKI/Rostf6g8IXwbewQSkxEDH52jftz5DpxyD+oojQLDNB7m8TR3EAK A/EA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=v/fBCawgbNr9z8sHoDyBwn+JenP5278dLuCFcze5nO4=; b=YTsYUj0+kIbZbOda1JoxCYOECzgeZ5anm4pB5yDQih+SgnLFaQX+CA/oOBfVDPWJzY bOYoBPad0aXhHilxuEWDUgDT23vo9xJrpJeiOEAqdKPLFQGxyuXhwTxjFXokrK4HEWu9 gg+JF9zgBEjQSXB7/DTyp5wG9rMC+B3z8IREmTHngsfdF8tiGjUd/t6r0pmjE6sreVVj Y2mCSBX5b4dIyD3hNcQNcBlrz723dfVjTCdFf/UjEQvfMxFtFXm8ShMdnBhyYh/hr73D dkHKCXgBARLri5aAiC1uVNzwf9yiiiUxlojIz1TGVgns+1szizWtxCUvxb11Tset76nu QvDA== X-Gm-Message-State: APjAAAXid2JpEo5zb+MQba8e7tATeC4V5kOVN0z2XGrEtJDzIy3YGxUB H0KLjDx+kqOIzehe+ptjuCrnDXQt3A== X-Google-Smtp-Source: APXvYqztjJN/esR+L3OUI4QZ+K5dhvl1Dd08UL4fO1/9xBiWuMOU3zCx1yGn64DkSaz9eoQ3fDi32RAqJw== X-Received: by 2002:a5d:4808:: with SMTP id l8mr23085087wrq.118.1572877758478; Mon, 04 Nov 2019 06:29:18 -0800 (PST) Date: Mon, 4 Nov 2019 15:27:45 +0100 In-Reply-To: <20191104142745.14722-1-elver@google.com> Message-Id: <20191104142745.14722-10-elver@google.com> Mime-Version: 1.0 References: <20191104142745.14722-1-elver@google.com> X-Mailer: git-send-email 2.24.0.rc1.363.gb1bccd3e3d-goog Subject: [PATCH v3 9/9] x86, kcsan: Enable KCSAN for x86 From: Marco Elver To: elver@google.com Cc: akiyks@gmail.com, stern@rowland.harvard.edu, glider@google.com, parri.andrea@gmail.com, andreyknvl@google.com, luto@kernel.org, ard.biesheuvel@linaro.org, arnd@arndb.de, boqun.feng@gmail.com, bp@alien8.de, dja@axtens.net, dlustig@nvidia.com, dave.hansen@linux.intel.com, dhowells@redhat.com, dvyukov@google.com, hpa@zytor.com, mingo@redhat.com, j.alglave@ucl.ac.uk, joel@joelfernandes.org, corbet@lwn.net, jpoimboe@redhat.com, luc.maranget@inria.fr, mark.rutland@arm.com, npiggin@gmail.com, paulmck@kernel.org, peterz@infradead.org, tglx@linutronix.de, will@kernel.org, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This patch enables KCSAN for x86, with updates to build rules to not use KCSAN for several incompatible compilation units. Signed-off-by: Marco Elver --- v3: * Moved EFI stub build exception hunk to generic build exception patch, since it's not x86-specific. v2: * Document build exceptions where no previous above comment explained why we cannot instrument. --- arch/x86/Kconfig | 1 + arch/x86/boot/Makefile | 2 ++ arch/x86/boot/compressed/Makefile | 2 ++ arch/x86/entry/vdso/Makefile | 3 +++ arch/x86/include/asm/bitops.h | 6 +++++- arch/x86/kernel/Makefile | 7 +++++++ arch/x86/kernel/cpu/Makefile | 3 +++ arch/x86/lib/Makefile | 4 ++++ arch/x86/mm/Makefile | 3 +++ arch/x86/purgatory/Makefile | 2 ++ arch/x86/realmode/Makefile | 3 +++ arch/x86/realmode/rm/Makefile | 3 +++ 12 files changed, 38 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index d6e1faa28c58..81859be4a005 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -226,6 +226,7 @@ config X86 select VIRT_TO_BUS select X86_FEATURE_NAMES if PROC_FS select PROC_PID_ARCH_STATUS if PROC_FS + select HAVE_ARCH_KCSAN if X86_64 config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index e2839b5c246c..9c7942794164 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -9,7 +9,9 @@ # Changed by many, many contributors over the years. # +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Kernel does not boot with kcov instrumentation here. diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 6b84afdd7538..a1c248b8439f 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -17,7 +17,9 @@ # (see scripts/Makefile.lib size_append) # compressed vmlinux.bin.all + u32 size of vmlinux.bin.all +# Sanitizer runtimes are unavailable and cannot be linked for early boot code. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 0f2154106d01..a23debaad5b9 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -10,8 +10,11 @@ ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE include $(srctree)/lib/vdso/Makefile KBUILD_CFLAGS += $(DISABLE_LTO) + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n UBSAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 7d1f6a49bfae..ee08917d3d92 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -201,8 +201,12 @@ arch_test_and_change_bit(long nr, volatile unsigned long *addr) return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr); } -static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) +static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) { + /* + * Because this is a plain access, we need to disable KCSAN here to + * avoid double instrumentation via bitops-instrumented.h. + */ return ((1UL << (nr & (BITS_PER_LONG-1))) & (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; } diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 3578ad248bc9..2aa122d94956 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -28,6 +28,13 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n KASAN_SANITIZE_stacktrace.o := n KASAN_SANITIZE_paravirt.o := n +# Do not instrument early boot code. +KCSAN_SANITIZE_head$(BITS).o := n +# Do not instrument debug code to avoid corrupting bug reporting. +KCSAN_SANITIZE_dumpstack.o := n +KCSAN_SANITIZE_dumpstack_$(BITS).o := n +KCSAN_SANITIZE_stacktrace.o := n + OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y OBJECT_FILES_NON_STANDARD_test_nx.o := y OBJECT_FILES_NON_STANDARD_paravirt_patch.o := y diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index d7a1e5a9331c..1f1b0edc0187 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -13,6 +13,9 @@ endif KCOV_INSTRUMENT_common.o := n KCOV_INSTRUMENT_perf_event.o := n +# As above, instrumenting secondary CPU boot code causes boot hangs. +KCSAN_SANITIZE_common.o := n + # Make sure load_percpu_segment has no stackprotector nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_common.o := $(nostackp) diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 5246db42de45..432a07705677 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -6,10 +6,14 @@ # Produces uninteresting flaky coverage. KCOV_INSTRUMENT_delay.o := n +# KCSAN uses udelay for introducing watchpoint delay; avoid recursion. +KCSAN_SANITIZE_delay.o := n + # Early boot use of cmdline; don't instrument it ifdef CONFIG_AMD_MEM_ENCRYPT KCOV_INSTRUMENT_cmdline.o := n KASAN_SANITIZE_cmdline.o := n +KCSAN_SANITIZE_cmdline.o := n ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_cmdline.o = -pg diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 84373dc9b341..ee871602f96a 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -7,6 +7,9 @@ KCOV_INSTRUMENT_mem_encrypt_identity.o := n KASAN_SANITIZE_mem_encrypt.o := n KASAN_SANITIZE_mem_encrypt_identity.o := n +KCSAN_SANITIZE_mem_encrypt.o := n +KCSAN_SANITIZE_mem_encrypt_identity.o := n + ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_mem_encrypt.o = -pg CFLAGS_REMOVE_mem_encrypt_identity.o = -pg diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index fb4ee5444379..69379bce9574 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -17,7 +17,9 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib targets += purgatory.ro +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n KCOV_INSTRUMENT := n # These are adjustments to the compiler flags used for objects that diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile index 682c895753d9..6b1f3a4eeb44 100644 --- a/arch/x86/realmode/Makefile +++ b/arch/x86/realmode/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y subdir- := rm diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index f60501a384f9..fdbbb945c216 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -6,7 +6,10 @@ # for more details. # # + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.