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 949EEC10F25 for ; Mon, 9 Mar 2020 19:05:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6541620637 for ; Mon, 9 Mar 2020 19:05:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583780750; bh=dmTYlWB7kxW8OXHx6yaSTsrH3kc4vn2vfr2xOrYY8Fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s1mMtmBKNywTkXz6q6XXDP9gg+oeeLW1m+szJP/7Acw3ntSVHL5tnlPKq1NE5QkiY T/pJX1y2QPRmei0J4gugLfwq7UhvyD+Ldl8TkaZttaQFT/xychdm6U1L98ab2Ed/8f zqChc9dS6r4VfDRMxD+UrwhN3NKYZNkfWLFkemuo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727904AbgCITFt (ORCPT ); Mon, 9 Mar 2020 15:05:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:47630 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727588AbgCITEZ (ORCPT ); Mon, 9 Mar 2020 15:04:25 -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 56EE524654; Mon, 9 Mar 2020 19:04:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583780665; bh=dmTYlWB7kxW8OXHx6yaSTsrH3kc4vn2vfr2xOrYY8Fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z+YIvqnlsSfeteE99FXBBOxC2PcBKtUyyc7zj0rs03i/9vit7pQ2cD1uvK1myO26G hYcQq/lKird3txDVrbAXrYu9YYv5PdSnYCoy7YruHXQzs4bV84K8a0l+te33C7dmsj A9RO9g/Hj911mosECWqVy056NDKcCrk3owb4SVSQ= 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 13/32] kcsan: Clarify Kconfig option KCSAN_IGNORE_ATOMICS Date: Mon, 9 Mar 2020 12:04:01 -0700 Message-Id: <20200309190420.6100-13-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200309190359.GA5822@paulmck-ThinkPad-P72> References: <20200309190359.GA5822@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 Clarify difference between options KCSAN_IGNORE_ATOMICS and KCSAN_ASSUME_PLAIN_WRITES_ATOMIC in help text. Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney --- lib/Kconfig.kcsan | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index 6612685..020ac63 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -132,8 +132,18 @@ config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC config KCSAN_IGNORE_ATOMICS bool "Do not instrument marked atomic accesses" help - If enabled, never instruments marked atomic accesses. This results in - not reporting data races where one access is atomic and the other is - a plain access. + Never instrument marked atomic accesses. This option can be used for + additional filtering. Conflicting marked atomic reads and plain + writes will never be reported as a data race, however, will cause + plain reads and marked writes to result in "unknown origin" reports. + If combined with CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=n, data + races where at least one access is marked atomic will never be + reported. + + Similar to KCSAN_ASSUME_PLAIN_WRITES_ATOMIC, but including unaligned + accesses, conflicting marked atomic reads and plain writes will not + be reported as data races; however, unlike that option, data races + due to two conflicting plain writes will be reported (aligned and + unaligned, if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n). endif # KCSAN -- 2.9.5