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 X-Spam-Level: X-Spam-Status: No, score=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 517A4C433DF for ; Thu, 18 Jun 2020 09:32:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BDFC21974 for ; Thu, 18 Jun 2020 09:32:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="C8BIq7mE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729214AbgFRJcK (ORCPT ); Thu, 18 Jun 2020 05:32:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729197AbgFRJcF (ORCPT ); Thu, 18 Jun 2020 05:32:05 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A03EAC0613ED for ; Thu, 18 Jun 2020 02:32:05 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id k186so5743289yba.18 for ; Thu, 18 Jun 2020 02:32:05 -0700 (PDT) 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=wAC/0zMBk1R1mKjHS4CraP1dln5upgDgvVtxjRPVBbA=; b=C8BIq7mEJOO8a5LHVQ1SuDhcysfjMc5V2zuefaCD1/AohUdWCQ6EzEpjc/S+CtyVqD 1IhMpQrvVmfXwSUu+I9vQF1+c/54BZFxIKOdFnpCS6XgDWQJ4LQNWdZkuvXVf5PkgisN OMuF+A5L2J5RCry6wyradYuB/UTxB8gGYvWfpT7ZXyWQLjVVZAB36ligjDfkOAXazDmg C+lKnEOrLJsGhipSA01GmPwzu7HWTekfnJ3m0MhcTjtdUgLmAlR2X7ReYnwzZFgJLmO2 U5hkTjCWaNLWE9rRwvvU3WjYa6roSqQgnXBu7zdU/5DcTFHM2ecWAy4ESfuivG5UBR1Z 5o6w== 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=wAC/0zMBk1R1mKjHS4CraP1dln5upgDgvVtxjRPVBbA=; b=XpXTI7N+5MpOm6mw2Vo9k3oqSzdDzDHVvUhsYs9BODKgX8VD2oz4UbapEAVoJgH7E3 qWnRDE1UDJBq8/X/CeR6YsH5J6MqCpcBNx+TIrjbKAPIbEzvMag1wmDHlDdF9WQ+ZUwq n5PPU38YWYnJzaLDbs8EHwBtACBvVKOuyEDWkB7ZgpwV5Blxl7trfDUKtlx6qZ58+OIs yMu3Zhjv2PR4mCZCSbJLFc/Vk8M3JAdzYmplVkS3fkAfACECLOOyj0z3FVGNT0Jjsnf8 kmXkV0upf9Msg2/juw/gcOF6UfhbErh9RxNlrQjTQ7w5eDOIRq4GWzTC838xyWpiryRh dE+w== X-Gm-Message-State: AOAM532EIDa0/SKMRjVZOAbesh0AjlJOKBwgdceFm+N9fE57TtN5RRey WToUbffBXX2VtHe7K3VU8vstPkCCBA== X-Google-Smtp-Source: ABdhPJyoNvmUy6LQW6lg0uXVx0KMGkjLhkRReal6sqe7bk+aXHSMMR5P0LvdBpXockzmMqxZT8kS9TKSlg== X-Received: by 2002:a25:348a:: with SMTP id b132mr5314699yba.491.1592472724817; Thu, 18 Jun 2020 02:32:04 -0700 (PDT) Date: Thu, 18 Jun 2020 11:31:18 +0200 In-Reply-To: <20200618093118.247375-1-elver@google.com> Message-Id: <20200618093118.247375-4-elver@google.com> Mime-Version: 1.0 References: <20200618093118.247375-1-elver@google.com> X-Mailer: git-send-email 2.27.0.290.gba653c62da-goog Subject: [PATCH 3/3] kcsan: Disable branch tracing in core runtime From: Marco Elver To: elver@google.com, paulmck@kernel.org Cc: will@kernel.org, peterz@infradead.org, bp@alien8.de, tglx@linutronix.de, mingo@kernel.org, dvyukov@google.com, cai@lca.pw, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Disable branch tracing in core KCSAN runtime if branches are being traced (TRACE_BRANCH_PROFILING). This it to avoid its performance impact, but also avoid recursion in case KCSAN is enabled for the branch tracing runtime. The latter had already been a problem for KASAN: https://lore.kernel.org/lkml/CANpmjNOeXmD5E3O50Z3MjkiuCYaYOPyi+1rq=GZvEKwBvLR0Ug@mail.gmail.com/ Signed-off-by: Marco Elver --- kernel/kcsan/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index fea064afc4f7..65ca5539c470 100644 --- a/kernel/kcsan/Makefile +++ b/kernel/kcsan/Makefile @@ -8,7 +8,7 @@ CFLAGS_REMOVE_debugfs.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE) CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \ - -fno-stack-protector + -fno-stack-protector -DDISABLE_BRANCH_PROFILING obj-y := core.o debugfs.o report.o obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o -- 2.27.0.290.gba653c62da-goog