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 1F1B3C35247 for ; Tue, 4 Feb 2020 17:21:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E62362082E for ; Tue, 4 Feb 2020 17:21:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QQ0ZB6uu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727507AbgBDRVg (ORCPT ); Tue, 4 Feb 2020 12:21:36 -0500 Received: from mail-ua1-f74.google.com ([209.85.222.74]:57226 "EHLO mail-ua1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727334AbgBDRVf (ORCPT ); Tue, 4 Feb 2020 12:21:35 -0500 Received: by mail-ua1-f74.google.com with SMTP id b15so5057419uas.23 for ; Tue, 04 Feb 2020 09:21:35 -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=P5Zl9LQYe0TwoSBlL27JA/OuhbAcWy+b13rTN8vanpc=; b=QQ0ZB6uuqbxCJElvNJUgezUS9U6tosI0PZypsN0qkNsnv8Q5ab7WkP44YW9MlwxLa5 p1A+xVX18I0IsONIy3AGkxpYM1iJP2xssabLbdjsqRqVHYUpNc8FvAATeI6/SxOUzpYH TDq3tfoRXHGaZiPvYTZXVSm9zWwKFZZTDKwhQLSdrlDjYFRbb0rl5veBZ35WqR2tGJMn aiywLjOnlKgvtjSOc+LLxfvkwdqp5aLJv5yv5Sf9WbAyctIbpGdJqNOa3fTNqWxFW3q9 Em/OVGsyxOqHNY/iGfA/nWumKOnRmynQRKf+i3LYrKntb8lNxj4JgVkvZ7ul7LduO4nn ghgA== 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=P5Zl9LQYe0TwoSBlL27JA/OuhbAcWy+b13rTN8vanpc=; b=YW2NEcCKl86fNV0q6IkbWTtxn9dkBN431V/lhZTotywGKnZ/OaTLmyyG9DWdITtHX/ /idLAhx0yzEyyvEpJKOBsX7GiWi2krYzarxwgyZT2hUEa2POJ+eSMNPQYtUN/EQS/0kR mc5pK0Dyp3j8bNBgvl6H31BS1keZy0XZX1KtNt0oC31DAARqRAJa/RP8wsYj7NT9z5RJ 6PmK5pY78NhCENy+E7QGL8uvVRFz7WBJRv9a3NaZyoDCBRxP/zvk7FT0wqHcwrz4mmfC TPP+EtH8Fcp/SqGhCe1FxYf3n2cuBW7E1FO5bQH0OTUg6ty9did9QckAhz6rhAbn0UJx hVrg== X-Gm-Message-State: APjAAAXJgrxa1FFAif4AUd7jrbDOLH569+wzwtFOx+bjaWd74yt7b+Q2 k3VHT0lvTOLKbhI0xF2Y7YxpGynBRg== X-Google-Smtp-Source: APXvYqwFQgJtsGlJlVyMC5UJR7gARCZMcqT2mxfWx6E5XwMyiGKF8uu5MTEINJPmX+QRk3Vapx6+Wd6skg== X-Received: by 2002:a1f:db81:: with SMTP id s123mr17780179vkg.45.1580836894663; Tue, 04 Feb 2020 09:21:34 -0800 (PST) Date: Tue, 4 Feb 2020 18:21:11 +0100 In-Reply-To: <20200204172112.234455-1-elver@google.com> Message-Id: <20200204172112.234455-2-elver@google.com> Mime-Version: 1.0 References: <20200204172112.234455-1-elver@google.com> X-Mailer: git-send-email 2.25.0.341.g760bfbb309-goog Subject: [PATCH v2 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 --- v2: * Update help text to mention alignment w.r.t. previous option. --- lib/Kconfig.kcsan | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index 66126853dab02..020ac63e43617 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 -- 2.25.0.341.g760bfbb309-goog