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[23.128.96.18]) by mx.google.com with ESMTP id c18si11573880ioz.59.2021.08.29.09.36.38; Sun, 29 Aug 2021 09:37:06 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=peDy6i5U; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235620AbhH2QgD (ORCPT + 99 others); Sun, 29 Aug 2021 12:36:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229712AbhH2QgC (ORCPT ); Sun, 29 Aug 2021 12:36:02 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 738B9C061575 for ; Sun, 29 Aug 2021 09:35:10 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id q21so7133705plq.3 for ; Sun, 29 Aug 2021 09:35:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=nX/8usvBr9iehSgRf8mOX3h/0C5tkpiOob1CFtQiaAY=; b=peDy6i5U/mdu7GAL/uQ7gUbaHU9AwkvHkZ9zEMGSu7KlKGtX8HDptLeonlwte5wY0Y nk5VlakJCNfYqUi3qBHDnaYTCgODCG1hl331RkyW9espvPlu7MurxnoDeHCMvc1juE/f aKhhY67WD0hm76CVV5uloaaYH7wJYGZ6fC3zcbTchpYLI8RzD6M/JJXsIICksG4qAyqr cOMXVDNOeH9+Kxd2xab5Rk5b5kk0Et/rAzN2JrKGpF4+FaHPufmSdn29af8I0BjqolaU 751qtaXNh6CUtzKo91B15aKqpHYU11ReBtn9EoVQyITcORI9nzmkDB5Ao94BAkBGdWqD RApQ== 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:content-transfer-encoding; bh=nX/8usvBr9iehSgRf8mOX3h/0C5tkpiOob1CFtQiaAY=; b=fZhfK8V3b2NVYMdrLPQ247FaWfkmu+I+L+H+edfqsN9R4VRY2K2yFs3xke9HKS5yUm vcyyHelChLzK34Qe3pyx7M84t+wPuRxgZ5+cKshBvUncSquwsD8/xTjmMjhQzj+dKmHv SCfS+M7UeWsPUVIKJ+ThoSmelL0hw+cdtBgDGCwRfPFLEoodRGSEz4kJGPAgU42/u0nZ DqL9wIiZEcAnnVvpjwKNsPf/KtJ36L6tgTYb8okymZhPNi3Xg3pE9/Fj/FfDbJTdxbdj sCknQT2rwuQhinzGIH9LDCjV5Y4f+7OzwZpGak1ZL3NFO5Re9tqNLnbdoW1QwE1UD1Gc LJGQ== X-Gm-Message-State: AOAM532SHu+Cc7gmwOCBfuY6Um68oCSpOetu2vyFbx0MqPnOVT3PWep1 95eU6QzvgjIzuQ1kXJTbDqM5PEjEw/zNiZR+xJ4= X-Received: by 2002:a17:90a:520c:: with SMTP id v12mr20050485pjh.105.1630254909694; Sun, 29 Aug 2021 09:35:09 -0700 (PDT) MIME-Version: 1.0 References: <20210829144531.c2syu4vv4s22dlg7@h510> In-Reply-To: From: Krish Jain Date: Sun, 29 Aug 2021 18:34:58 +0200 Message-ID: Subject: Re: [PATCH] Declare the file_operations struct as const To: Bryan Brattlof Cc: Greg KH , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org And I scoured the kernel.org website and I can't seem to find how my .config file is incorrect. I let make oldconfig && make prepare generate it for me. I am really confused. Can you give me another hint? I still get $ make CCFLAGS=3D-Werror W=3D1 M=3Ddrivers/staging/android/ V=3D1 test -e include/generated/autoconf.h -a -e include/config/auto.conf || ( \ echo >&2; \ echo >&2 " ERROR: Kernel configuration is invalid."; \ echo >&2 " include/generated/autoconf.h or include/config/auto.conf are missing.";\ echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \ echo >&2 ; \ /bin/false) make -f ./scripts/Makefile.build obj=3Ddrivers/staging/android \ single-build=3D \ need-builtin=3D1 need-modorder=3D1 sh ./scripts/modules-check.sh drivers/staging/android/modules.order make -f ./scripts/Makefile.modpost WARNING: Symbol version dump "Module.symvers" is missing. Modules may not have dependencies or modversions. You may get many unresolved symbol warnings. make -f ./scripts/Makefile.modfinal - Krish On Sun, Aug 29, 2021 at 6:20 PM Krish Jain wrote= : > > On Sun, Aug 29, 2021 at 4:45 PM Bryan Brattlof = wrote: > > > > Hi Krish > > > > On this day, August 29, 2021, thus sayeth Krish Jain: > > > On Sun, Aug 29, 2021 at 8:17 AM Greg KH = wrote: > > > > > > > > On Sun, Aug 29, 2021 at 04:13:43AM +0200, Krish Jain wrote: > > > > > On Sat, Aug 28, 2021 at 1:38 AM Bryan Brattlof wrote: > > > > > > As for your patch, I built the driver using: > > > > > > > > > > > > $ make CCFLAGS=3D-Werror W=3D1 M=3Ddrivers/staging/android > > > > > > > > > > > > Which produced the following error: > > > > > > > > > > > > > > > > > > drivers/staging/android/ashmem.c: In function =E2=80=98ashmem_m= map=E2=80=99: > > > > > > drivers/staging/android/ashmem.c:380:2: warning: =E2=80=98stati= c=E2=80=99 is not at beginning of declaration [-Wold-style-declaration] > > > > > > 380 | const static struct file_operations vmfile_fops; > > > > > > | ^~~~~ > > > > > > drivers/staging/android/ashmem.c:431:16: error: assignment of r= ead-only variable =E2=80=98vmfile_fops=E2=80=99 > > > > > > 431 | vmfile_fops =3D *vmfile->f_op; > > > > > > | ^ > > > > > > drivers/staging/android/ashmem.c:432:21: error: assignment of m= ember =E2=80=98mmap=E2=80=99 in read-only object > > > > > > 432 | vmfile_fops.mmap =3D ashmem_vmfile_mmap; > > > > > > | ^ > > > > > > drivers/staging/android/ashmem.c:433:34: error: assignment of m= ember =E2=80=98get_unmapped_area=E2=80=99 in read-only object > > > > > > 433 | vmfile_fops.get_unmapped_area =3D > > > > > > | ^ > > > > > > make[1]: *** [scripts/Makefile.build:271: drivers/staging/andro= id/ashmem.o] Error 1 > > > > > > make: *** [Makefile:1851: drivers/staging/android] Error 2 > > > > > > > > > > > > > > > > Hi, this seems very useful and I tried this myself just now. I do= n't > > > > > get any errors that you do though. When I hit enter I just get a = new > > > > > shell prompt. What am I doing wrong? Probably a silly mistake. I = ran > > > > > make CCFLAGS=3D-Werror M=3Ddrivers/staging/android/. > > > > > > > > Are you sure the file is being built at all? You usually have to s= elect > > > > the proper configuration option to enable that driver as well. > > > > > > > > > Hi, what option do you mean? I already ran make allmodconfig and sud= o > > > make modules_install install and then make "CCFLAGS=3D-Werror W=3D1 > > > M=3Ddrivers/staging/android/" and now I do get output but one line > > > "WARNING: Symbol version dump "Module.symvers" is missing. Modules ma= y > > > not have dependencies or modversions. You may get many unresolved > > > symbol warnings." . Then I tried "make CCFLAGS=3D-Werror V=3D1 > > > M=3Ddrivers/staging/android/" and that outputted the following: > > > > > > > Most of the answers you're asking for are going to get vague responses > > (if any) on the mailing lists. The idea being (and I agree with) that > > giving out the answers will steal your opportunity to explore and learn > > the material yourself. > > > > Yes, it would be faster if we told you the answer, but ultimately, we > > would be doing a disservice to you. > > > > Besides, more times than not we (me especially) don't have the answer. > > > > With that said, I will give a (generous) hint. :) > > > > Hi. Do I have to build the kernel once before this works? Or can I > just build a module directly? > > > > Best Regards > > > > > > It looks like your having trouble with Kconfig. Have a look at: > > > > https://www.kernel.org/doc/html/latest/kbuild/makefiles.html > > > > and: > > > > https://www.kernel.org/doc/html/latest/kbuild/modules.html > > > > Also, you shouldn't need to install anything if you're just testing > > whether a module builds. Especially when 'sudo' and 'install' are > > involved. > > > > > > > > test -e include/generated/autoconf.h -a -e include/config/auto.conf |= | ( \ > > > echo >&2; \ > > > echo >&2 " ERROR: Kernel configuration is invalid."; \ > > > echo >&2 " include/generated/autoconf.h or > > > include/config/auto.conf are missing.";\ > > > echo >&2 " Run 'make oldconfig && make prepare' on kernel src > > > to fix it."; \ > > > > > > > If I were you I would be asking: > > > > "What is a Kernel configuration file? and how did I corrupt mine?" > > > > https://www.kernel.org/doc/html/latest/kbuild/kconfig.html > > > > > > > > echo >&2 ; \ > > > /bin/false) > > > make -f ./scripts/Makefile.build obj=3Ddrivers/staging/android \ > > > single-build=3D \ > > > need-builtin=3D1 need-modorder=3D1 > > > sh ./scripts/modules-check.sh drivers/staging/android/modules.order > > > make -f ./scripts/Makefile.modpost > > > WARNING: Symbol version dump "Module.symvers" is missing. > > > Modules may not have dependencies or modversions. > > > You may get many unresolved symbol warnings. > > > make -f ./scripts/Makefile.modfinal > > > > > > > "What is Module.symvers?" > > > > If you're reading the links I gave, you should know this by now. :) > > Check out chapter 6 in "Building External Modules" > > > > > > > > I followed this and ran make oldconfig && make prepare but all that i= s > > > outputted is again "WARNING: Symbol version dump "Module.symvers" is > > > missing. Modules may not have dependencies or modversions. You may ge= t > > > many unresolved symbol warnings." Then I just tried sudo make > > > modules_install install again and what was outputted was: > > > > > > > Again, Be *VERY* careful running commands you do not understand. > > Especially when the words 'sudo' and 'install' are in the same > > command. > > > > > > > > sed: can't read modules.order: No such file or directory > > > make[1]: *** [Makefile:1494: __modinst_pre] Error 2 > > > make: *** [Makefile:351: __build_one_by_one] Error 2 > > > > > > > "What does modules.order do?" > > > > https://www.kernel.org/doc/html/latest/kbuild/kbuild.html > > > > > > > > Any ideas? I've been stuck on debugging for hours to no avail. Pleas= e > > > enlighten me on where I am messing up. > > > > > > > All I can say is the kernels' documentation is the greatest thing to > > have when joining the community. The search bar is *fantastic*. > > > > https://www.kernel.org/doc/html/latest/index.html > > > > Together with the collective history of ~30 years of developer's > > conversations on Linux Kernel Mailing List (LMKL). > > > > https://lore.kernel.org/lkml/ > > > > Along with our ability to see the full commit history at any time by: > > > > $ git grep > > > > In the end, all of the questions you have are in the documentation. I > > can't stress enough how appreciative we should be of contributers to > > Documentation/ and people like Jonathan Corbet who take the time to > > document how all of this stuff works in such a straight forward way. > > > > Withholding simple answers like this may seem unfair, but the juice is > > absolutely worth the squeeze the next time you run into another issue. > > > > And trust me when I say you *will* run into another issue. We wouldn't > > be here if there weren't constant issues to solve. > > > > We've all been where you're at. Even Greg, he may deny this, but I'm > > sure he has been. > > > > I'm excited to see what you learn. > > ~Bryan > > > > *** > > > > Just as an aside, for any other lurkers out there: This was the email > > that gave me confidence that I could join this community and that > > sending a patch, no matter how small, is welcome. > > > > https://lore.kernel.org/lkml/Pine.LNX.4.58.0412201646220.4112@ppc970.= osdl.org/ > > > > The old "grey-beards" here don't bite, no matter how much they and > > everyone else say they do. > >