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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 B5B7FC282DD for ; Thu, 9 Jan 2020 14:38:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5D4B22075D for ; Thu, 9 Jan 2020 14:38:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VGWzCDUS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D4B22075D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ADAB08E0018; Thu, 9 Jan 2020 09:38:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A8B6E8E0017; Thu, 9 Jan 2020 09:38:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9534E8E0018; Thu, 9 Jan 2020 09:38:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id 7C43D8E0017 for ; Thu, 9 Jan 2020 09:38:23 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 2DEBA485A for ; Thu, 9 Jan 2020 14:38:23 +0000 (UTC) X-FDA: 76358351286.19.tank45_663eefa75b933 X-HE-Tag: tank45_663eefa75b933 X-Filterd-Recvd-Size: 5185 Received: from mail-wr1-f67.google.com (mail-wr1-f67.google.com [209.85.221.67]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Jan 2020 14:38:22 +0000 (UTC) Received: by mail-wr1-f67.google.com with SMTP id q6so7606056wro.9 for ; Thu, 09 Jan 2020 06:38:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6rLPYvB46ykH23cOU/wxgD1zSAPVRYzaf1/Xm0R2qQw=; b=VGWzCDUSXAuGNnAfYy1yoBIi/etYAR+fm5rQbp2k6jAlzNj/WZQs8KdjqoqoxiJwhL ip0B3S26aVD2pQS8rl2eHO6MW4yKC/Asy0e3tM8PN6ZjqZhPnjPtyfuoRBxKsIEO7A4F SJW5sqOlADUF+J2URxzKl/8wwHV+3Q2fw1W0VD2jRHQ0vQXNEojxsRj5Jlb3ffgGwPJG 8x3SC6LTdB3hoWFQlMMHGNw6uJ4A1DS5jcivYeFtHroURvbJSi9UnyxDlO1mnijvdvo+ f073SGfL0aThuPv1BwlUMHhlzuS5CQv/Omnhp5lOGF0At50qpSKXkNMvgFcoHKncbrMI N+7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6rLPYvB46ykH23cOU/wxgD1zSAPVRYzaf1/Xm0R2qQw=; b=qR6e6tCOPhgLgC2BCSypU6UPXkZnOhYzr6Jt2zJAWO0EG2Bzmhftd6dBwH+iZw2STA F+zlvvCX/eFWKKsTaIiXgKrx7k1sX5Eeh4hFIXigg679ADl2pQR4atYQuru3+bLGesC+ Hb9BBp/OB5GP0VoqOh33mF8GGVH31cegsb4nYmHBr4xyswZ0YfIoFySwPP6zPjsCmDKh YjTuzZKRfnw+K2I6GoP/mTU9hQYGpqrMf2WcD8YL2jQwKvhEZbvDRgGwQfX59USy9JMQ /oPmthOSQcMzbu8NxHoBpXYS/JobkT1b0HPUAAzWwSLtoGCnEBXjpCVUOGwFf46+jwh4 ZLEA== X-Gm-Message-State: APjAAAVuVczJDlriJRgmb9kIIe9iWdGcmaNS+S5cbq6nmIWQX0s+JwH8 NwucdFkEuySCiHIcdLrOzsOaQV3gQ0GhR5iDdaMP0g== X-Google-Smtp-Source: APXvYqy0p92tAvivUWEBd+H7ZMOCP4PGJNG1BKR7Um1k9cA5VZ/SczyVcYaqgmYbVjM1yBFFcUGj6oZAFc/KhM0d8tc= X-Received: by 2002:a5d:6886:: with SMTP id h6mr11331878wru.154.1578580701003; Thu, 09 Jan 2020 06:38:21 -0800 (PST) MIME-Version: 1.0 References: <20191220184955.223741-1-glider@google.com> <20191223075141.GK13335@unreal> In-Reply-To: <20191223075141.GK13335@unreal> From: Alexander Potapenko Date: Thu, 9 Jan 2020 15:38:09 +0100 Message-ID: Subject: Re: [PATCH RFC v4 00/42] Add KernelMemorySanitizer infrastructure To: Leon Romanovsky Cc: Alexander Viro , Andreas Dilger , Andrew Morton , Andrey Konovalov , Andrey Ryabinin , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Christoph Hellwig , Christoph Hellwig , "Darrick J. Wong" , "David S. Miller" , Dmitry Torokhov , Dmitry Vyukov , Eric Biggers , Eric Dumazet , Eric Van Hensbergen , Greg Kroah-Hartman , Harry Wentland , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jason Wang , Jens Axboe , Marek Szyprowski , Marco Elver , Mark Rutland , "Martin K. Petersen" , Martin Schwidefsky , Matthew Wilcox , "Michael S. Tsirkin" , Michal Simek , Petr Mladek , Qian Cai , Randy Dunlap , Robin Murphy , Sergey Senozhatsky , Steven Rostedt , Takashi Iwai , "Theodore Ts'o" , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Wolfram Sang , Linux Memory Management List , Michal Hocko Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > > 2. checkpatch.pl complains a lot about the use of BUG_ON in KMSAN > > source. I don't have a strong opinion on this, but KMSAN is a debugging > > tool, so any runtime invariant violation in it renders the tool useless. > > Therefore it doesn't make much sense to not terminate after a bug in > > KMSAN. > > Such early termination will cause hard time for verification teams > execute any major test suite with KMSAN till it will be without any bugs. > So yes, I think that the best solution is to avoid BUG_ONs in non-critical code. > To clarify, these BUG_ONs are for bugs in KMSAN itself. KMSAN reports don't provoke a BUG(), so many of them can be reported at once. Proceeding after a bug in the debugging tool itself might be a bad idea - any broken invariant denotes that all following reports may be incorrect.