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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 79AB8C2BA19 for ; Thu, 9 Apr 2020 19:46:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35D5A2074F for ; Thu, 9 Apr 2020 19:46:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="e3z7QB/j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726786AbgDITqp (ORCPT ); Thu, 9 Apr 2020 15:46:45 -0400 Received: from mail-qk1-f194.google.com ([209.85.222.194]:33968 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbgDITqo (ORCPT ); Thu, 9 Apr 2020 15:46:44 -0400 Received: by mail-qk1-f194.google.com with SMTP id i186so5378844qke.1; Thu, 09 Apr 2020 12:46:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=vcnNkYD65cZvHPdMFn+PkHSwRz/TrLDpN2V4DWblgRE=; b=e3z7QB/jwEcj721jqewkO7fb5y+Gs1Vr1HTN3GPOwIQJRcyp54MX8a/Xqj4gvEO08i YpkrvIBTs3mw20tpILgmBV5i8O1lsV0NkD0vqSoJbDU1RuY5YPhPRfKHRGB+htmBRT9F 6GZSydJJ86nphbJIMDNZBRpzEjNEefIzfYuitxJdYXS4l103lHCrhh3fKdri8gK/LiDT sOra30ylymtvld9WFiI4xF3WjKFMq0hnxOnQbBa+9O30H9GU36qSmNdRYvvjey/93UqZ MVCCAiRK2s3/MMJ9oKC7fFV/ycD6EytT5xZm2yy47zHinjyjAwov5lBYoli3hUS7H8tR BELQ== 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:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=vcnNkYD65cZvHPdMFn+PkHSwRz/TrLDpN2V4DWblgRE=; b=sqUSBBrR+OiPUmU5MraaGTUjUxD3hI1OW1MTsbdWP7OMzsvzwBMxBoBOsKhSaIfd1o KN8pOnuHPHhBPxoyoB/Ri19SdVa/3TfYHgDLUes0q89IwOOpC5sVeFpoRhrwBDasDqxb ysLr2Qh7iDoo5KanA1O3zY/FQRbijXpgi1L9WJ5HmcIZ2wut7rzUfSiWV7ogDH0RAAHZ dQO3p72jHKCNNgyhfOSn9cZby02K37+MBFGg4WRj7ETuFziuOU8cpXiv/rTLrgIp+Ehz r4qeKZnEkxORajeSTvj0zF3A1xm/I7p9qdM26zma488hJu6kdDy5VRxF1qQ/rW9BbHXE dETA== X-Gm-Message-State: AGi0PuZwdFUCR/6DnvKp3EKOEb8dHFBv5ALGyevlaZpz4+zw6C1oqxL1 lknTR3txds4s1wVsYc9aZbk= X-Google-Smtp-Source: APiQypIt6LelOTKkqavBPWscgik8cCZv/c1vfkxoes5ZNKr1W1wfqnB7S8lROVaWSbvvXF62OaReQg== X-Received: by 2002:a37:c246:: with SMTP id j6mr562717qkm.298.1586461602477; Thu, 09 Apr 2020 12:46:42 -0700 (PDT) Received: from darkstar ([177.89.165.183]) by smtp.gmail.com with ESMTPSA id l3sm10710912qkl.85.2020.04.09.12.46.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2020 12:46:41 -0700 (PDT) Date: Thu, 9 Apr 2020 16:46:37 -0300 From: Cristian Souza To: Matthew Wilcox , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, corbet@lwn.net Subject: Re: [PATCH v2] docs: admin-guide: Clarify sentences Message-ID: <20200409194637.GA141700@darkstar> References: <20200408144653.GA123268@darkstar> <20200409181311.GW21484@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200409181311.GW21484@bombadil.infradead.org> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Removal of unnecessary sentences, identification of authors at the top of the file, and correction of the number of characters per line. Signed-off-by: Cristian Souza --- Documentation/admin-guide/init.rst | 57 +++++++++++++++--------------- 1 file changed, 28 insertions(+), 29 deletions(-) diff --git a/Documentation/admin-guide/init.rst b/Documentation/admin-guide/init.rst index 0c2c9138f268..41f06a09152e 100644 --- a/Documentation/admin-guide/init.rst +++ b/Documentation/admin-guide/init.rst @@ -1,38 +1,39 @@ Explaining the "No working init found." boot hang message ========================================================= - -Message location: ``init/main.c`` +:Authors: Andreas Mohr + Cristian Souza This document provides some high-level reasons for failure (listed roughly in order of execution) to load the init binary. -1) **Unable to mount root FS**: Set "debug" kernel parameter (in bootloader config file or CONFIG_CMDLINE) - to get more detailed kernel messages. +1) **Unable to mount root FS**: Set "debug" kernel parameter (in bootloader + config file or CONFIG_CMDLINE) to get more detailed kernel messages. -2) **init binary doesn't exist on rootfs**: Make sure you have the correct root FS type - (and ``root=`` kernel parameter points to the correct partition), - required drivers such as storage hardware (such as SCSI or USB!) - and filesystem (ext3, jffs2, etc.) are builtin (alternatively as modules, - to be pre-loaded by an initrd). +2) **init binary doesn't exist on rootfs**: Make sure you have the correct + root FS type (and ``root=`` kernel parameter points to the correct + partition), required drivers such as storage hardware (such as SCSI or + USB!) and filesystem (ext3, jffs2, etc.) are builtin (alternatively as + modules, to be pre-loaded by an initrd). -3) **Broken console device**: Possibly a conflict in ``console= setup`` --> initial console unavailable. - E.g. some serial consoles are unreliable due to serial IRQ issues (e.g. - missing interrupt-based configuration). +3) **Broken console device**: Possibly a conflict in ``console= setup`` + --> initial console unavailable. E.g. some serial consoles are unreliable + due to serial IRQ issues (e.g. missing interrupt-based configuration). Try using a different ``console= device`` or e.g. ``netconsole=``. -4) **Binary exists but dependencies not available**: E.g. required library dependencies of the init binary such as - ``/lib/ld-linux.so.2`` missing or broken. Use - ``readelf -d |grep NEEDED`` to find out which libraries are required. - -5) **Binary cannot be loaded**: Make sure the binary's architecture matches your hardware. - E.g. i386 vs. x86_64 mismatch, or trying to load x86 on ARM hardware. - In case you tried loading a non-binary file here (shell script?), - you should make sure that the script specifies an interpreter in its shebang - header line (``#!/...``) that is fully working (including its library - dependencies). And before tackling scripts, better first test a simple - non-script binary such as ``/bin/sh`` and confirm its successful execution. - To find out more, add code ``to init/main.c`` to display kernel_execve()s - return values. +4) **Binary exists but dependencies not available**: E.g. required library + dependencies of the init binary such as ``/lib/ld-linux.so.2`` missing or + broken. Use ``readelf -d |grep NEEDED`` to find out which libraries + are required. + +5) **Binary cannot be loaded**: Make sure the binary's architecture matches + your hardware. E.g. i386 vs. x86_64 mismatch, or trying to load x86 on ARM + hardware. In case you tried loading a non-binary file here (shell script?), + you should make sure that the script specifies an interpreter in its + shebang header line (``#!/...``) that is fully working (including its + library dependencies). And before tackling scripts, better first test a + simple non-script binary such as ``/bin/sh`` and confirm its successful + execution. To find out more, add code ``to init/main.c`` to display + kernel_execve()s return values. Please extend this explanation whenever you find new failure causes (after all loading the init binary is a CRITICAL and hard transition step @@ -42,8 +43,6 @@ Further TODOs: - Implement the various ``run_init_process()`` invocations via a struct array which can then store the ``kernel_execve()`` result value and on failure log it all by iterating over **all** results (very important usability fix). -- Try to make the implementation itself more helpful in general, - e.g. by providing additional error messages at affected places. +- Try to make the implementation itself more helpful in general, e.g. by + providing additional error messages at affected places. -Andreas Mohr -Cristian Souza -- 2.25.1