Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
MIME-Version: 1.0
References: <CAK7LNAT3N82cJD3GsF+yUBEfPNOBkhzYPk37q3k0HdU7ukz9vQ@mail.gmail.com>
 <32b332af189bfca8acdb231cee294355aa4af290.1701892062.git.msuchanek@suse.de>
In-Reply-To: <32b332af189bfca8acdb231cee294355aa4af290.1701892062.git.msuchanek@suse.de>
From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Mon, 11 Dec 2023 03:43:44 +0900
Message-ID: <CAK7LNATPF7baHLXZVgzz=6zOhLx8maX0r0EU3DBFwAEZ6kCeww@mail.gmail.com>
Subject: Re: [PATCH v6 1/2] depmod: Handle installing modules under a
 different directory
To:     Michal Suchanek <msuchanek@suse.de>
Cc:     linux-modules@vger.kernel.org, Takashi Iwai <tiwai@suse.com>,
        Lucas De Marchi <lucas.de.marchi@gmail.com>,
        =?UTF-8?Q?Michal_Koutn=C3=BD?= <mkoutny@suse.com>,
        Jiri Slaby <jslaby@suse.com>, Jan Engelhardt <jengelh@inai.de>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Thu, Dec 7, 2023 at 4:48=E2=80=AFAM Michal Suchanek <msuchanek@suse.de> =
wrote:
>
> Some distributions aim at shipping all files in /usr.
>
> The path under which kernel modules are installed is hardcoded to /lib
> which conflicts with this goal.
>
> When kmod provides kmod.pc, use it to determine the correct module
> installation path.
>
> With kmod that does not provide the config /lib/modules is used as
> before.
>
> While pkg-config does not return an error when a variable does not exist
> the kmod configure script puts some effort into ensuring that
> module_directory is non-empty. With that empty module_directory from
> pkg-config can be used to detect absence of the variable.
>
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> ---
> v6:
>  - use ?=3D instead of :=3D to make it easier to override the value


"KERNEL_MODULE_DIRECTORY=3D/local/usr/lib/modules make modules_install"
will override the install destination, but
depmod will not be not aware of it.

How to avoid the depmod error?


>  - use shorter expression for determining the module directory assuming
>    it's non-empty
> ---
>  Makefile | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 511b5616aa41..84f32bd563d4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1081,7 +1081,9 @@ export INSTALL_DTBS_PATH ?=3D $(INSTALL_PATH)/dtbs/=
$(KERNELRELEASE)
>  # makefile but the argument can be passed to make if needed.
>  #
>
> -MODLIB =3D $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
> +export KERNEL_MODULE_DIRECTORY ?=3D $(or $(shell pkg-config --variable=
=3Dmodule_directory kmod 2>/dev/null),/lib/modules)
> +
> +MODLIB =3D $(INSTALL_MOD_PATH)$(KERNEL_MODULE_DIRECTORY)/$(KERNELRELEASE=
)
>  export MODLIB
>
>  PHONY +=3D prepare0
> --
> 2.42.0
>
>


--
Best Regards
Masahiro Yamada