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 2CDECC2D0B1 for ; Tue, 4 Feb 2020 14:04:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E14812082E for ; Tue, 4 Feb 2020 14:04:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PD1xyBi0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727272AbgBDOE2 (ORCPT ); Tue, 4 Feb 2020 09:04:28 -0500 Received: from mail-wm1-f74.google.com ([209.85.128.74]:42237 "EHLO mail-wm1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727207AbgBDOE1 (ORCPT ); Tue, 4 Feb 2020 09:04:27 -0500 Received: by mail-wm1-f74.google.com with SMTP id d4so1214757wmd.7 for ; Tue, 04 Feb 2020 06:04:26 -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=KtW08c4N/a2oVRHrX0WYeOZxmDiJvCqs/eWAvVn9zAs=; b=PD1xyBi0it61cmDpiG9PZDHp+qhrT9OgiLa82dmTHx3mddRhqfoKzbkfPY1XlNNED0 edSeM6QjA66SGyS7wMEMBCGRbNtF7148dzzX39l8q2w7n/27ooIO322AbDdTDjrfKF06 f1CLml824JYqce7RAxlqd+crkwigfWwWQO6p3pzKKr6bHEDj8ORD5Kggu6v+GxrXjQ1b HsTvlBfg2uBzwesMshwo/2VT365sljDfLwYD2GCsyDFBsQzc+EE6otCdRegG/9iIBrL6 a6Bs/11+rrYsbR3cdCqwPT5edlj+Hh58bWupgDkk6rHlIc0WQHlIdxBRtMczt3LExH6v w2rA== 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=KtW08c4N/a2oVRHrX0WYeOZxmDiJvCqs/eWAvVn9zAs=; b=F/qlfaHGHHjZeFw81pI7YlGYCplWOir+MQ/wuAQj41hdu15c2x8qtBx7qq1DQ13f/w 2sk0ZZURQH/jjfhnDuThVKHYBd0aIYw5OdQvrYg0XGu+MRsj4QSunrYNVRygj5vmpUk9 osbyKly9kQlwsFCirtqJJS7GqVj3d6qFOtUFSpt3oeEi92LmFAKtjhBIVTJ3N+mwmaxY tJ8x2RszE7oqFyZQfZ7UlMamuxlOXcfd0uhtqOtJB8vLUSpX36CfO106QTsEgzqei56p +4Dyjlh3fOVC1GHMnQ9Lf8Ds1+SicY+ByFnegI6HyvTnQ0+5QrWP3jW+RAFiicvgaVbm r/HQ== X-Gm-Message-State: APjAAAVfNb0EWe3j2t6eipghLFcaF6Xgq9vd5TgBBpNk7vXRUKlWcqJO mnLB+ug+vaZtoUF44OU1lB3bxkyuNQ== X-Google-Smtp-Source: APXvYqwncnT9r1x/4RrOaQtvjXAN3GZnAkUK2m/xSD2a6Esfjkx3lDl1yjliLAza6WZ3i1YNQcjujfzqQQ== X-Received: by 2002:adf:fa86:: with SMTP id h6mr21824539wrr.418.1580825050694; Tue, 04 Feb 2020 06:04:10 -0800 (PST) Date: Tue, 4 Feb 2020 15:03:52 +0100 In-Reply-To: <20200204140353.177797-1-elver@google.com> Message-Id: <20200204140353.177797-2-elver@google.com> Mime-Version: 1.0 References: <20200204140353.177797-1-elver@google.com> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog Subject: [PATCH 2/3] kcsan: Clarify Kconfig option KCSAN_IGNORE_ATOMICS From: Marco Elver To: elver@google.com Cc: paulmck@kernel.org, andreyknvl@google.com, glider@google.com, dvyukov@google.com, 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 Clarify difference between options KCSAN_IGNORE_ATOMICS and KCSAN_ASSUME_PLAIN_WRITES_ATOMIC in help text. Signed-off-by: Marco Elver --- lib/Kconfig.kcsan | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index 08972376f0454..35fab63111d75 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -131,8 +131,17 @@ 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 + more advanced 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. + + Like KCSAN_ASSUME_PLAIN_WRITES_ATOMIC, 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 (if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n). endif # KCSAN -- 2.25.0.341.g760bfbb309-goog