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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 C9D4EC43381 for ; Wed, 20 Mar 2019 10:59:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6F7252175B for ; Wed, 20 Mar 2019 10:59:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F7252175B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=i-love.sakura.ne.jp Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B453A6B0003; Wed, 20 Mar 2019 06:59:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AF33A6B0006; Wed, 20 Mar 2019 06:59:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A0A336B0007; Wed, 20 Mar 2019 06:59:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-io1-f71.google.com (mail-io1-f71.google.com [209.85.166.71]) by kanga.kvack.org (Postfix) with ESMTP id 8252B6B0003 for ; Wed, 20 Mar 2019 06:59:24 -0400 (EDT) Received: by mail-io1-f71.google.com with SMTP id c2so1638615ioh.11 for ; Wed, 20 Mar 2019 03:59:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:to:cc :references:from:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=ycICQOOMlMirl8Ygz0OWOM1s2tUooMo9WIQjH1NTjzg=; b=Y7zZpNFG/HreI0MR59EqBpFuNVcBp6IPZi23HvPOienYSD77NFGlqf4Ov90WgUpYiO 7je59deUmPwOQJwt6Yr364jBEWp8z/edVZyT9yO29+XZzu321A+9Yiptct3TPfE3AVbN 6PUM/iywKOTB8bzAwZ7P9ejRO9kPlHmGekV+F0NgkwAESMWRwMznzHv8sTpIVJjWT8Bh 5i5GDhyoP8nn+LHh2mr+4iBVlnrVsVBpBx9dTFK6ETfkBfwX7jDmixlvEzsCcy5iroum xr+VhhwhVLhZFLjWG53raEQEwLYtDk6IKPEcn+/QejOSAJyl9UhPlRRopZFI/+xsv+Tv jcPw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp X-Gm-Message-State: APjAAAVfoHU5LefCffDuG8jobq26SlbaegzSakdH7fPBeWl98cadMz36 Uqlyd7eIzDwHKwmop4YptqxoK/kTZUgVkR6CbvjI9qL4CG2X/cEhYZeIsYs0/OX1+XHE3SZKOb+ nfcrodIzkAQHKmcqirol9jkjMOevGdhd3COGvEp7ZFY6xje5HWwK/dFy1ZaLNhJedUg== X-Received: by 2002:a6b:1495:: with SMTP id 143mr4538395iou.201.1553079564313; Wed, 20 Mar 2019 03:59:24 -0700 (PDT) X-Google-Smtp-Source: APXvYqxResN1mISoBSiXgWnFm9BBPoFqPmJMx/U0gWRWbzErF9isSaSmAWpvMQEUZN5L/6dUXEM0 X-Received: by 2002:a6b:1495:: with SMTP id 143mr4538371iou.201.1553079563652; Wed, 20 Mar 2019 03:59:23 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1553079563; cv=none; d=google.com; s=arc-20160816; b=NMAWM9X734F8LKkP6BxOcsgx3/rfaWdECSnlwHFK0zSqnEQEauqOxT4bwaJa/uLdFa guSDOIOws+jdq2HpWe0FU2MSdUVIBIgWKK5Mil7xffTHczIQGbaVUFdpXb2t9tVjdpYz kEVFUcXCLGRbW1vrrOtJi4Kq482dvqNnPSLfA2EqxFZZNi+2ll6TZ749K3ybXN6keO+e e5c8ymT8WLT5IDiUNdA/vb8hW7RpmLx8kp1wMgiT3Nwf3DJsU+vmZSELxca0QKXNMAuU mrsrc9qDhpRsXkmDve9RIhg1F5M4VETYr/pFjESJNUmcXM4e7WczsHVRQJR0F/jOmDMA 2JMg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject; bh=ycICQOOMlMirl8Ygz0OWOM1s2tUooMo9WIQjH1NTjzg=; b=kQJ9kT7BVQZ6f/HSq7WfkH7nl9fyNhTKvh2/qRA+6ZtFv29XbzQ5fL3GkS4h4y4omd ouso7z5mknt0RkHoBvBAM9Pz34LRSAdlkCEoBGv4Uc7laYxpoQyZRnreGyPV+BFai0O9 IrkvN3zGvyXm6Qk55vNSWdrDVncDisMYeTFEC1A+asjpumWWjqT/MNyW/BB26I6UpG5s 3MU/MsxqqSj4P0mLJRpN1jClcuzCCHnSTe7fc9JpYwRJgD5tXrKygpondd+mqr5TDRFG yxjfHpxuCS37XYzjcrd4OX33PzFcZLVMK8W5KLRHgINmpzDFLQ9sYOlfvY0WetAB0Hub VGfA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [202.181.97.72]) by mx.google.com with ESMTPS id j1si730310jal.92.2019.03.20.03.59.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Mar 2019 03:59:23 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) client-ip=202.181.97.72; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of penguin-kernel@i-love.sakura.ne.jp designates 202.181.97.72 as permitted sender) smtp.mailfrom=penguin-kernel@i-love.sakura.ne.jp Received: from fsav402.sakura.ne.jp (fsav402.sakura.ne.jp [133.242.250.101]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x2KAwoWH033716; Wed, 20 Mar 2019 19:58:50 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav402.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav402.sakura.ne.jp); Wed, 20 Mar 2019 19:58:50 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav402.sakura.ne.jp) Received: from [192.168.1.8] (softbank126094122116.bbtec.net [126.94.122.116]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id x2KAwn1v033709 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NO); Wed, 20 Mar 2019 19:58:50 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: kernel panic: corrupted stack end in wb_workfn To: Dmitry Vyukov Cc: Andrey Ryabinin , syzbot , Andrew Morton , Qian Cai , David Miller , guro@fb.com, Johannes Weiner , Josef Bacik , Kirill Tkhai , LKML , Linux-MM , linux-sctp@vger.kernel.org, Mel Gorman , Michal Hocko , netdev , Neil Horman , Shakeel Butt , syzkaller-bugs , Al Viro , Vladislav Yasevich , Matthew Wilcox , Xin Long References: <000000000000db3d130584506672@google.com> <426293c3-bf63-88ad-06fb-83927ab0d7c0@I-love.SAKURA.ne.jp> From: Tetsuo Handa Message-ID: Date: Wed, 20 Mar 2019 19:58:48 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 2019/03/20 19:42, Dmitry Vyukov wrote: >> I mean, yes, I agree, kernel bug bisection won't be perfect. But do >> you see anything actionable here? Allow users to manually tell bisection range when automatic bisection found a wrong commit. Also, allow users to specify reproducer program when automatic bisection found a wrong commit. Yes, this is anti automation. But since automation can't become perfect, I'm suggesting manual adjustment. Even if we involve manual adjustment, the syzbot's plenty CPU resources for building/testing kernels is highly appreciated (compared to doing manual bisection by building/testing kernels on personal PC environments). > > I see the larger long term bisection quality improvement (for syzbot > and for everybody else) in doing some actual testing for each kernel > commit before it's being merged into any kernel tree, so that we have > less of these a single program triggers 3 different bugs, stray > unrelated bugs, broken release boots, etc. I don't see how reliable > bisection is possible without that. > syzbot currently cannot test kernels with custom patches (unless "#syz test:" requests). Are you saying that syzbot will become be able to test kernels with custom patches?