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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 CF208C433E0 for ; Wed, 24 Jun 2020 19:03:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A447F20836 for ; Wed, 24 Jun 2020 19:03:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593025401; bh=YYqTV8Zr8/5F9AirsUFsM2FCNcZA3ZF1sVGi1jazgBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DLy4h1cLRg2IHbi9/WSYnygeRB9//Kmgt5kvp7bFsJTLpQ0mE1SAhMgVTSad4YJsz goH9DaMQnwD15ACqA4fLoIUStuI5XiaprlSsTLKLMBmVdvN+v8xni/XqTFaQ6rcTsv Q/CzzL9KRPp9s0l0ADzRLAU3ckTVvT/DD1HZ4Grw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406162AbgFXTDU (ORCPT ); Wed, 24 Jun 2020 15:03:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:55556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404767AbgFXTDK (ORCPT ); Wed, 24 Jun 2020 15:03:10 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F415020B80; Wed, 24 Jun 2020 19:03:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593025390; bh=YYqTV8Zr8/5F9AirsUFsM2FCNcZA3ZF1sVGi1jazgBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=swkiOYkWbnYu+iQvYlbCgoiUAFg2MxYMRA0gzJqz7twzMDdSbtNMJ3vPivvMG5Csm Bbgo88tno+yEuJGh2gwpTfgUiAuo8aIcXyQq/S3rGGYIoDgn/D6uCIzMO4ViB7cDnw EhVthcjDSaX8B3eWuOufIcNpcv+S8/ca25/f0KD4= From: paulmck@kernel.org To: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, kernel-team@fb.com, mingo@kernel.org Cc: elver@google.com, andreyknvl@google.com, glider@google.com, dvyukov@google.com, cai@lca.pw, boqun.feng@gmail.com, "Paul E . McKenney" Subject: [PATCH kcsan 3/3] kcsan: Disable branch tracing in core runtime Date: Wed, 24 Jun 2020 12:03:07 -0700 Message-Id: <20200624190307.15191-3-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200624190236.GA6603@paulmck-ThinkPad-P72> References: <20200624190236.GA6603@paulmck-ThinkPad-P72> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marco Elver 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 Signed-off-by: Paul E. McKenney --- kernel/kcsan/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index fea064a..65ca553 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 -- 2.9.5