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=-8.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1, 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 46322ECE587 for ; Mon, 14 Oct 2019 14:44:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 201C120854 for ; Mon, 14 Oct 2019 14:44:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="R4Sv0nu/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732972AbfJNOoo (ORCPT ); Mon, 14 Oct 2019 10:44:44 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:54626 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731121AbfJNOon (ORCPT ); Mon, 14 Oct 2019 10:44:43 -0400 Received: by mail-wm1-f68.google.com with SMTP id p7so17578225wmp.4 for ; Mon, 14 Oct 2019 07:44:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=lV9WUHRQYa+vcbnXaIrl9dHPzPBQxfzmjkh8HTlj1Bg=; b=R4Sv0nu/0zTthcOB5gdAeVN4GjOy9iItL0K/CL5nKP+gYb8+0NlbvVtDbWrASvGTFg Xq15G3Gif4VH+0edHvuVUs3yIveqxdNZS+8W6cN8Flbst2a09CdpfrX6aj/yKZ1HvxOG cQU1WqMXDcgvms+37/3cqYRyAB5jN2IxSxkEyEBgja6lyNdKXHm0CEv1CMkA8A+C5OWg 43HJiqe22PxAK/W1GQfdSX6aDYU4+E4RJnH8Y8nwGD/OLM46seNi4tRfEWtaWljw1njn v6hKrQOmlP1FYMfLEPltHPE+Lmo/zYA5/AtOZspeSJfUN9bqOQMmuTW+F49uO98xA3J+ dvjg== 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:content-transfer-encoding :in-reply-to:user-agent; bh=lV9WUHRQYa+vcbnXaIrl9dHPzPBQxfzmjkh8HTlj1Bg=; b=VlqP1eA6Y10vO+Fnu/1+6nuoDzoAvCHAdpwS8SdZf+dIiR4BI+OzCgzV4PjUylKsDz RVwj+1Sv703O/EnVqssFY31OP5TQu+iZ9Oe44+wmXUnegd9vOsX5xQPqPmeDkHaQH6ma TELHv0rvq2TF4GOKxfmVexwbh7hOsMOvYpHMvc+2pnD4aVoJk5gcFFNbvrmR/EHOYDom 1LKhRHsB2oidwd+HkG9JUl/7bCDYYrLzpMDEdPTHXrt9rc5gxJ8JNkgMEz+46Je+SgpJ K322+b3hhx0xTptu2U4vPvwbelvTQ/AIZmADybpNIQCUTqH6tiWElhkMNxwJ7PyuMmLE wWSg== X-Gm-Message-State: APjAAAUz6zAPoeR6CUE7nUah2MZ0l182h8hQkMeIfy0IPjgoPG79X8lH OgWsw1MjU256knQ4mJvW/auoYg== X-Google-Smtp-Source: APXvYqzTSv6CMEyQM3i6C4SK/hTjeAMaTon8/RvoovUvDlefqH05gxDzk92qF3PTigpHHIEcQwWRyw== X-Received: by 2002:a05:600c:2481:: with SMTP id 1mr14687975wms.98.1571064280936; Mon, 14 Oct 2019 07:44:40 -0700 (PDT) Received: from google.com ([2a00:79e0:d:210:e8f7:125b:61e9:733d]) by smtp.gmail.com with ESMTPSA id z189sm33273049wmc.25.2019.10.14.07.44.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Oct 2019 07:44:40 -0700 (PDT) Date: Mon, 14 Oct 2019 15:44:40 +0100 From: Matthias Maennich To: Luis Chamberlain Cc: Heiner Kallweit , Jessica Yu , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Andrew Lunn , Florian Fainelli Subject: Re: Module loading problem since 5.3 Message-ID: <20191014144440.GG35313@google.com> References: <20191014085235.GW16384@42.do-not-panic.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191014085235.GW16384@42.do-not-panic.com> 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 Hi Luis! On Mon, Oct 14, 2019 at 08:52:35AM +0000, Luis Chamberlain wrote: >On Fri, Oct 11, 2019 at 09:26:05PM +0200, Heiner Kallweit wrote: >> On 10.10.2019 19:15, Luis Chamberlain wrote: >> > >> > >> > On Thu, Oct 10, 2019, 6:50 PM Heiner Kallweit > wrote: >> > >> >    MODULE_SOFTDEP("pre: realtek") >> > >> > Are you aware of any current issues with module loading >> > that could cause this problem? >> > >> > >> > Nope. But then again I was not aware of MODULE_SOFTDEP(). I'd encourage an extension to lib/kmod.c or something similar which stress tests this. One way that comes to mind to test this is to allow a new tests case which loads two drives which co depend on each other using this macro. That'll surely blow things up fast. That is, the current kmod tests uses request_module() or get_fs_type(), you'd want a new test case with this added using then two new dummy test drivers with the macro dependency. >> > >> > If you want to resolve this using a more tested path, you could have request_module() be used as that is currently tested. Perhaps a test patch for that can rule out if it's the macro magic which is the issue. >> > >> >   Luis >> >> Maybe issue is related to a bug in introduction of symbol namespaces, see here: >> https://lkml.org/lkml/2019/10/11/659 > >Can you have your user with issues either revert 8651ec01daed or apply the fixes >mentioned by Matthias to see if that was the issue? > >Matthias what module did you run into which let you run into the issue >with depmod? I ask as I think it would be wise for us to add a test case >using lib/test_kmod.c and tools/testing/selftests/kmod/kmod.sh for the >regression you detected. The depmod warning can be reproduced when using a symbol that is built into vmlinux and used from a module. E.g. with CONFIG_USB_STORAGE=y and CONFIG_USB_UAS=m, the symbol `usb_stor_adjust_quirks` is built in with namespace USB_STORAGE and depmod stumbles upon this emitting the following warning (e.g. during make modules_install). depmod: WARNING: [...]/uas.ko needs unknown symbol usb_stor_adjust_quirks As there is another (less intrusive) way of implementing the namespace feature, I posted a patch series [1] on last Thursday that should mitigate the issue as the ksymtab entries depmod eventually relies on are no longer carrying the namespace in their names. Cheers, Matthias [1] https://lore.kernel.org/lkml/20191010151443.7399-1-maennich@google.com/ > > Luis