From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-13.3 required=5.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 02E2C7D90D for ; Thu, 17 Oct 2019 14:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437146AbfJQON1 (ORCPT ); Thu, 17 Oct 2019 10:13:27 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:38337 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394793AbfJQON1 (ORCPT ); Thu, 17 Oct 2019 10:13:27 -0400 Received: by mail-qk1-f202.google.com with SMTP id s28so2273661qkm.5 for ; Thu, 17 Oct 2019 07:13:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=ahMy3naCKZUNeyQrUsfvkWdO2IwHI3ehg2cI/CL0H68=; b=E3NOAAWoSp5dTlcTqruPb+cH4PFuBjXLsewnlVjecfeBooxgaCsyFAL8vBl4YeNT20 YoLFJaTQQjJxVpax9nNayHjSAHQWsOgddwQzwVv9JYC2Au2zuxFrCmfiSl9eCwPUjiB/ pk3jnb5D0FkO31sy7aMLhRtuJadpGsEwRytCDgR6jcXDBDOxJjFs0dwm0FdaDrDknV8x iZ4CEs9UkGQdbcr+x9W6pe8+HRjM1yuiBP8veMvjpf/zMPwj8nV1oMSQ5FPQT9RSoE+Q ZKOXMtWQzET90Ll9U8y/HRyW7pSXTSbMg792SlUvduaz7O4I5Ec1BPXkNa7CJ+bB12Z9 42Sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=ahMy3naCKZUNeyQrUsfvkWdO2IwHI3ehg2cI/CL0H68=; b=Sq+450DXTpxpPa6Kqh6Z74X7+3aSHNhwfCPvHu0DTJMOx/pp1cf05DydKPoigZQ6QG hHaIIMUXCO3oleLlPqDeKxDsEYa8FWgoIN+Z0iJ68t+YJkj8DOYdi37yGnz4RZUGyxof FDgngrTuobmQSodlNy+XEhcZocrayU3RM7u9H6bv6+GrEcucVpl/+TrEXJpE9Nb/oU4l El8by44H15pAZuY0uRxSzEUMcFmEiPzEig0Ygg0oUF7qMDSY0gKIrFdp863G1IQ9uSW/ lnp84/tOuTC+Faqmtej/WkcJlqAjhnORHQwgU3wQmDHFk23sA/ByGL0/ghqEGpxoIHEu rYmQ== X-Gm-Message-State: APjAAAWHowLFzXOfzhZ7B9TXem9jOYZVkOBeYL9PUmVmCX9NeZauoM4n M/RbCsr72tD9M60jEVsGb0/qGuR7Fw== X-Google-Smtp-Source: APXvYqxtX9ypXjB03uUDF7iJQHTkx8t43nT/o1OPlwEgu5Pcb4Oyr25eGL9asgyz9sNtX0vCtLKQRCysMg== X-Received: by 2002:ac8:1903:: with SMTP id t3mr4137772qtj.344.1571321605784; Thu, 17 Oct 2019 07:13:25 -0700 (PDT) Date: Thu, 17 Oct 2019 16:12:57 +0200 Message-Id: <20191017141305.146193-1-elver@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH v2 0/8] Add Kernel Concurrency Sanitizer (KCSAN) 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@linux.ibm.com, 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org This is the patch-series for the Kernel Concurrency Sanitizer (KCSAN). KCSAN is a sampling watchpoint-based data-race detector. More details are included in Documentation/dev-tools/kcsan.rst. This patch-series only enables KCSAN for x86, but we expect adding support for other architectures is relatively straightforward (we are aware of experimental ARM64 and POWER support). To gather early feedback, we announced KCSAN back in September, and have integrated the feedback where possible: http://lkml.kernel.org/r/CANpmjNPJ_bHjfLZCAPV23AXFfiPiyXXqqu72n6TgWzb2Gnu1eA@mail.gmail.com We want to point out and acknowledge the work surrounding the LKMM, including several articles that motivate why data-races are dangerous [1, 2], justifying a data-race detector such as KCSAN. [1] https://lwn.net/Articles/793253/ [2] https://lwn.net/Articles/799218/ The current list of known upstream fixes for data-races found by KCSAN can be found here: https://github.com/google/ktsan/wiki/KCSAN#upstream-fixes-of-data-races-found-by-kcsan Changelog --------- v2: * Elaborate comment about instrumentation calls emitted by compilers. * Replace kcsan_check_access(.., {true, false}) with kcsan_check_{read,write} for improved readability. * Introduce __atomic_check_{read,write} in atomic-instrumented.h [Suggested by Mark Rutland]. * Change bug title of race of unknown origin to just say "data-race in". * Refine "Key Properties" in kcsan.rst, and mention observed slow-down. * Add comment about safety of find_watchpoint without user_access_save. * Remove unnecessary preempt_disable/enable and elaborate on comment why we want to disable interrupts and preemptions. * Use common struct kcsan_ctx in task_struct and for per-CPU interrupt contexts [Suggested by Mark Rutland]. * Document x86 build exceptions where no previous above comment explained why we cannot instrument. v1: http://lkml.kernel.org/r/20191016083959.186860-1-elver@google.com Marco Elver (8): kcsan: Add Kernel Concurrency Sanitizer infrastructure objtool, kcsan: Add KCSAN runtime functions to whitelist build, kcsan: Add KCSAN build exceptions seqlock, kcsan: Add annotations for KCSAN seqlock: Require WRITE_ONCE surrounding raw_seqcount_barrier asm-generic, kcsan: Add KCSAN instrumentation for bitops locking/atomics, kcsan: Add KCSAN instrumentation x86, kcsan: Enable KCSAN for x86 Documentation/dev-tools/kcsan.rst | 203 ++++++++++ MAINTAINERS | 11 + Makefile | 3 +- 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 + drivers/firmware/efi/libstub/Makefile | 2 + include/asm-generic/atomic-instrumented.h | 393 ++++++++++---------- include/asm-generic/bitops-instrumented.h | 18 + include/linux/compiler-clang.h | 9 + include/linux/compiler-gcc.h | 7 + include/linux/compiler.h | 35 +- include/linux/kcsan-checks.h | 147 ++++++++ include/linux/kcsan.h | 108 ++++++ include/linux/sched.h | 4 + include/linux/seqlock.h | 51 ++- init/init_task.c | 8 + init/main.c | 2 + kernel/Makefile | 6 + kernel/kcsan/Makefile | 14 + kernel/kcsan/atomic.c | 21 ++ kernel/kcsan/core.c | 428 ++++++++++++++++++++++ kernel/kcsan/debugfs.c | 225 ++++++++++++ kernel/kcsan/encoding.h | 94 +++++ kernel/kcsan/kcsan.c | 86 +++++ kernel/kcsan/kcsan.h | 140 +++++++ kernel/kcsan/report.c | 306 ++++++++++++++++ kernel/kcsan/test.c | 117 ++++++ kernel/sched/Makefile | 6 + lib/Kconfig.debug | 2 + lib/Kconfig.kcsan | 88 +++++ lib/Makefile | 3 + mm/Makefile | 8 + scripts/Makefile.kcsan | 6 + scripts/Makefile.lib | 10 + scripts/atomic/gen-atomic-instrumented.sh | 17 +- tools/objtool/check.c | 17 + 46 files changed, 2428 insertions(+), 206 deletions(-) create mode 100644 Documentation/dev-tools/kcsan.rst create mode 100644 include/linux/kcsan-checks.h create mode 100644 include/linux/kcsan.h create mode 100644 kernel/kcsan/Makefile create mode 100644 kernel/kcsan/atomic.c create mode 100644 kernel/kcsan/core.c create mode 100644 kernel/kcsan/debugfs.c create mode 100644 kernel/kcsan/encoding.h create mode 100644 kernel/kcsan/kcsan.c create mode 100644 kernel/kcsan/kcsan.h create mode 100644 kernel/kcsan/report.c create mode 100644 kernel/kcsan/test.c create mode 100644 lib/Kconfig.kcsan create mode 100644 scripts/Makefile.kcsan -- 2.23.0.866.gb869b98d4c-goog