From patchwork Thu Nov 14 18:03:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marco Elver X-Patchwork-Id: 11244159 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 481881892 for ; Thu, 14 Nov 2019 18:04:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E675C2071B for ; Thu, 14 Nov 2019 18:04:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="SnVWFOxr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E675C2071B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B880F6B0279; Thu, 14 Nov 2019 13:04:33 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id B38A26B027A; Thu, 14 Nov 2019 13:04:33 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A27116B027B; Thu, 14 Nov 2019 13:04:33 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 8AE456B0279 for ; Thu, 14 Nov 2019 13:04:33 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 4C1BC442C for ; Thu, 14 Nov 2019 18:04:33 +0000 (UTC) X-FDA: 76155658026.25.birth55_61df9c144d83d X-Spam-Summary: 30,2,0,a2fa5ab49e75807b,d41d8cd98f00b204,3lpfnxqukcicpw6p2rzzrwp.nzxwty58-xxv6lnv.z2r@flex--elver.bounces.google.com,:elver@google.com: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:edumazet@google.com: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::x86@kernel.org,RULES_HIT:1:2:41:152:355:379:491:541:800:960:968:973:982:988:989:1260:1277:1313:1314:1345:1359:14 37:1516: X-HE-Tag: birth55_61df9c144d83d X-Filterd-Recvd-Size: 11023 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 Nov 2019 18:04:32 +0000 (UTC) Received: by mail-wr1-f74.google.com with SMTP id f8so4902249wrq.6 for ; Thu, 14 Nov 2019 10:04:32 -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=V48+CW8SP21nJTw3n511EV0NzIrdGUkA/Mo6H0aYbCQ=; b=SnVWFOxrqhGVA3o/oVRrHRlEFYQ66/0SOV/8Wir2hZgl+5XkmZ/VYrGs3JQIw8jFjK EelP1k4At5P4DSpgmyTbTKjz36AYnTxrgzc50HLEdcxz9CdC3kdRAT++DeQww7U9K4Fx F65Pwx6zhDOIeb5DDoYUhUnHlvwxPP7lw0KWqas8ix+ODavAAHoDwyHrKwheQH1Y8+KG CtMtyXRimhLn+hhMV+bRu4XMp/H2LDnj8BU89YwnaQ2OqLD4HoLZeoEv/msHGertNbCi APS23YkUBb/261pr9MUO63D6yU8wRcsyN1Xw81gKUJNI7yX+g37aufSxFGTX6lN4mMcO T6VQ== 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=V48+CW8SP21nJTw3n511EV0NzIrdGUkA/Mo6H0aYbCQ=; b=VtNZLVqTLOB3ecDSBdtQzRN4YPFZGiYNBtNCjovJTG7ard+eh9KXRMVuxWT1pOtk7e 3g+lENo/bEZqsa3kFwlQoV8HDX/xRu2DDq0E2LmidgflF6DYlhdeu+QUmOnOsQxW5cvR entr9ntX1xo2uousZGVqWQuD8dxyhs+30HUF4Mt66RiJBeV2zh1qn1HYf6eEOvicuNp8 Le0fgsucVvqhMHHa8FnZzCTvNA7lDpKz4UTME46/WQQo002nUzvgB0k+msCaQS3T2iiz BTuOlBkYvo8HmSqZp+suDpNpi0g9OWqUDUGmhIZ5K2sOUU2WF6Q5VasEzenNrhb35eUC rrhQ== X-Gm-Message-State: APjAAAVVppkJ4oHW3uk3Jc1Wr7WwjxyDaKkRD2KlYBVr5MtCnkharTV5 KKyoZc/hVi7zdGjG3YYZAZE9YOLpsA== X-Google-Smtp-Source: APXvYqy5QdqQ6wSPNcmJk5EYF5HMESRJSKd4Bgh+yADSSABjRrCnB8uskBN1QWrSyICPt+TlDjVIPnmgEQ== X-Received: by 2002:adf:e50e:: with SMTP id j14mr8629262wrm.179.1573754670805; Thu, 14 Nov 2019 10:04:30 -0800 (PST) Date: Thu, 14 Nov 2019 19:03:03 +0100 In-Reply-To: <20191114180303.66955-1-elver@google.com> Message-Id: <20191114180303.66955-11-elver@google.com> Mime-Version: 1.0 References: <20191114180303.66955-1-elver@google.com> X-Mailer: git-send-email 2.24.0.rc1.363.gb1bccd3e3d-goog Subject: [PATCH v4 10/10] 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, edumazet@google.com, 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 Acked-by: Paul E. McKenney --- v4: * Fix code generation with clang (KCSAN_SANITIZE := n for affected compilation units). 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 | 4 ++++ arch/x86/kernel/cpu/Makefile | 3 +++ arch/x86/lib/Makefile | 4 ++++ arch/x86/mm/Makefile | 4 ++++ arch/x86/purgatory/Makefile | 2 ++ arch/x86/realmode/Makefile | 3 +++ arch/x86/realmode/rm/Makefile | 3 +++ 12 files changed, 36 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8ef85139553f..9933ca8ffe16 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 += $(DISABLE_LTO) + +# Sanitizer runtimes are unavailable and cannot be linked here. KASAN_SANITIZE := n UBSAN_SANITIZE := n +KCSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 7d1f6a49bfae..542b63ddc8aa 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -201,8 +201,12 @@ arch_test_and_change_bit(long nr, volatile unsigned long *addr) return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr); } -static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) +static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr) { + /* + * Because this is a plain access, we need to disable KCSAN here to + * avoid double instrumentation via instrumented bitops. + */ return ((1UL << (nr & (BITS_PER_LONG-1))) & (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; } diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 3578ad248bc9..a9a1cab437bc 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -28,6 +28,10 @@ KASAN_SANITIZE_dumpstack_$(BITS).o := n KASAN_SANITIZE_stacktrace.o := n KASAN_SANITIZE_paravirt.o := n +# With some compiler versions the generated code results in boot hangs, caused +# by several compilation units. To be safe, disable all instrumentation. +KCSAN_SANITIZE := 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 890f60083eca..a704fb9ee98e 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..3559f4297ee1 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -7,6 +7,10 @@ KCOV_INSTRUMENT_mem_encrypt_identity.o := n KASAN_SANITIZE_mem_encrypt.o := n KASAN_SANITIZE_mem_encrypt_identity.o := n +# Disable KCSAN entirely, because otherwise we get warnings that some functions +# reference __initdata sections. +KCSAN_SANITIZE := 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.