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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 8EB8EC43603 for ; Tue, 17 Dec 2019 08:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60E652072D for ; Tue, 17 Dec 2019 08:24:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NAm+XItX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726536AbfLQIYx (ORCPT ); Tue, 17 Dec 2019 03:24:53 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:44532 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725805AbfLQIYw (ORCPT ); Tue, 17 Dec 2019 03:24:52 -0500 Received: by mail-pj1-f66.google.com with SMTP id w5so4234490pjh.11 for ; Tue, 17 Dec 2019 00:24:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=oeT07/QwoKqTaqY/Bi4yvvkin+Xy8ImWNOXn4R8EJaw=; b=NAm+XItXgM1TQWT93ycGUKURg/INuZRS9zKT/FnFjkSXX7wp6msqp8Lhl4c/4zZiEV QqXG5F9xvoiHh5adQLwPalP/THL5bRR0IOvBKWparGGi9PJeoXYdzIJUhwzNdlELeGKE gpHfRxGh8HNagLpnIpsi7sfnCtT+0HO1kIRtyecHFL/utfLk5zGbYbOZCWhD1Eu6dKzq mN7++LrGMVWXBNeg8duaY3hLKVfxOcG97L2vK5lJCQ/LRX+djmgwSwjhb174qe/u9Mwu Lv5BkR8atKf8+H/TIwhtvUOOL+FzBwaiesUwyB8OlfErcl0EXDZDN6hNTEmvV4r5HNwr 2S0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=oeT07/QwoKqTaqY/Bi4yvvkin+Xy8ImWNOXn4R8EJaw=; b=ActWHDxz/jlq34w8qB8JpstI79W7LaTujNLFzt2FnsgtdeST1gbUSOVvpgjaBnON9L dCs/5n3lROPAGbjjvfJsL4eS3oGhZKBSlRO5Pf82HK6w4JhGa267ZcjbrSFfPJtmUgW/ 4cLsvFSB/skPtqFsxoPKKWdqxeYu5miO93zgNekQIMlldaR1epx6e5XmVJP8rSNDVaQ2 LJy+bltkH7u+fA6HBngswlKkiZ8eex6nFBTLlTzaUMkZ+UUXkl/8uzNiMNBkidLuVj02 3H1Y/6J7RJ1i2MkktHSCwYMxpGHtzuL4pNQxP53CQGmvTCSeHnssiocH7gvXGqHetwoX i86g== X-Gm-Message-State: APjAAAVG9ezuouYGkZu8YUg7lzKsxx9g7iYyjLkypNsDVbm0GDhB+Fiv eosi+ECtLiIKlK/mIDcitAY= X-Google-Smtp-Source: APXvYqyW7gXqj6pbkuwrWwBznN80lOfeuq4pUhBgBj3exxsN1LtJNO519DhStu01L5HrRHOjEVGsBA== X-Received: by 2002:a17:902:9f98:: with SMTP id g24mr21638765plq.325.1576571091870; Tue, 17 Dec 2019 00:24:51 -0800 (PST) Received: from localhost ([2401:fa00:8f:203:250d:e71d:5a0a:9afe]) by smtp.gmail.com with ESMTPSA id h128sm27593041pfe.172.2019.12.17.00.24.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Dec 2019 00:24:50 -0800 (PST) Date: Tue, 17 Dec 2019 17:24:49 +0900 From: Sergey Senozhatsky To: Dmitry Vyukov Cc: Sergey Senozhatsky , Tetsuo Handa , Alexander Viro , Petr Mladek , Sergey Senozhatsky , Arnd Bergmann , Greg Kroah-Hartman , Jiri Slaby , Steven Rostedt , Linus Torvalds , LKML Subject: Re: [PATCH] kconfig: Add kernel config option for fuzz testing. Message-ID: <20191217082449.GC54407@google.com> References: <20191216095955.9886-1-penguin-kernel@I-love.SAKURA.ne.jp> <20191217051234.GA54407@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (19/12/17 08:54), Dmitry Vyukov wrote: > On Tue, Dec 17, 2019 at 6:12 AM Sergey Senozhatsky > wrote: > > > > On (19/12/16 18:59), Tetsuo Handa wrote: > > > > Can you fuzz test with `ignore_loglevel'? > > We can set ignore_loglevel in syzbot configs, but won't it then print > everything including verbose debug output? What would be the most active source of debug output? dev_dbg(), which is dev_printk(KERN_DEBUG), can be compiled out, if I'm not mistaken. It probably depends on CONFIG_DEBUG or something similar, unlike dev_printk(), which depends on CONFIG_PRINTK. It seems that we have significantly more dev_dbg() users, than direct dev_printk(KERN_DEBUG). Does fuzz tester hit pr_debug() often? File systems? Some of them have ways to compile out debugging output as well. E.g. jbd_debug, _debug, ext4_debug, and so on. -ss