From nobody Sun Nov 24 00:38:58 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CCB814E2ED; Sun, 10 Nov 2024 01:37:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731202630; cv=none; b=PavzmLDNQESuGNErUBVw/KmxcbtPNZWe63/6aC9fwWq9D3fIdw+7rRXz8DZ/0/SiLjYfnK/QiF9X25pUzk+iFtq0q5uuk2tkZNQsh4qbZnB02DDVz/AY1TsE9BCcZ1RtEOW3j9ae45gZz/C+Jw0ZBu5zwwr3qNJnwTg0YZSupzg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731202630; c=relaxed/simple; bh=Wf268ApS1D6QJ4TyEFsF5qod3tLLDRZrfLTApp+4NVI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SrwmebUPx+M8jUjAXx00dmSIHX9bTUx35dgT5X+FS6lbD+vHsCOSyF+1d327yNMdDoICof1SG5YhALUAdtHIKrLsvMkTR9g+7pdrbQzPvU4l5qz9U8v3tpmVMntPzzMh9ktiTSVUvrJlXWmZ2VgnUMk1ISuWRxMCQgZfPU4OQqw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iGy/5q8R; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iGy/5q8R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB330C4CED4; Sun, 10 Nov 2024 01:37:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731202630; bh=Wf268ApS1D6QJ4TyEFsF5qod3tLLDRZrfLTApp+4NVI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iGy/5q8R96N0gt2yyUnabXRSlHEhCzw6rpmrevpY7csp+2OFpPbxjAV7WNgsIO91K kvgyshHY+E8rhnFv79EaxAn//O5gAsVUJWeEVTo7DfMTV/kG6iAyK6KYZXorXtANJe VFhxXhp6o0MVTo+ZcURcN3ZL6b8GOmVEf0ZkhBNEQqhRlWAGFaHP/gD85i0O1OdC2e BEYemZX0IRp3wvPoJbdoCZ3po8rDbkUe+h+1NakUH3jU99TEGpKHtLuvjdF95SduSB sRIQ3zi+pBO4Ev9264K/LZ8kfA/k94+KPWup79dS4/N7ONDVRA8U6AMwsf+DGTJyXc tIz0w5dT6Q9RA== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, cocci@inria.fr, Masahiro Yamada , Nicolas Schier Subject: [PATCH v2 07/11] kbuild: support building external modules in a separate build directory Date: Sun, 10 Nov 2024 10:34:35 +0900 Message-ID: <20241110013649.34903-8-masahiroy@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241110013649.34903-1-masahiroy@kernel.org> References: <20241110013649.34903-1-masahiroy@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There has been a long-standing request to support building external modules in a separate build directory. This commit introduces a new environment variable, KBUILD_EXTMOD_OUTPUT, and its shorthand Make variable, MO. A simple usage: $ make -C M=3D MO=3D Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- Changes in v2: - Add -I $(src) -I $(obj) for external modules as well - Fix a typo 'Speficies' to 'Specifies'. Documentation/kbuild/kbuild.rst | 8 +++++++- Documentation/kbuild/modules.rst | 8 +++++++- Makefile | 22 +++++++++++++++++++--- scripts/Makefile.host | 8 +++----- scripts/Makefile.lib | 2 -- 5 files changed, 36 insertions(+), 12 deletions(-) diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.= rst index 1796b3eba37b..17c9f920f03d 100644 --- a/Documentation/kbuild/kbuild.rst +++ b/Documentation/kbuild/kbuild.rst @@ -137,12 +137,18 @@ Specify the output directory when building the kernel. This variable can also be used to point to the kernel output directory when building external modules against a pre-built kernel in a separate build directory. Please note that this does NOT specify the output directory for= the -external modules themselves. +external modules themselves. (Use KBUILD_EXTMOD_OUTPUT for that purpose.) =20 The output directory can also be specified using "O=3D...". =20 Setting "O=3D..." takes precedence over KBUILD_OUTPUT. =20 +KBUILD_EXTMOD_OUTPUT +-------------------- +Specify the output directory for external modules. + +Setting "MO=3D..." takes precedence over KBUILD_EXTMOD_OUTPUT. + KBUILD_EXTRA_WARN ----------------- Specify the extra build checks. The same value can be assigned by passing diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/module= s.rst index cd5a54d91e6d..a01f3754c7fc 100644 --- a/Documentation/kbuild/modules.rst +++ b/Documentation/kbuild/modules.rst @@ -66,7 +66,10 @@ Options of the kernel output directory if the kernel was built in a separate build directory.) =20 - make -C $KDIR M=3D$PWD + You can optionally pass MO=3D option if you want to build the modules in + a separate directory. + + make -C $KDIR M=3D$PWD [MO=3D$BUILD_DIR] =20 -C $KDIR The directory that contains the kernel and relevant build @@ -80,6 +83,9 @@ Options directory where the external module (kbuild file) is located. =20 + MO=3D$BUILD_DIR + Specifies a separate output directory for the external module. + Targets ------- =20 diff --git a/Makefile b/Makefile index c7eeb10455b6..38ce19747728 100644 --- a/Makefile +++ b/Makefile @@ -134,6 +134,10 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD :=3D $(M) endif =20 +ifeq ("$(origin MO)", "command line") + KBUILD_EXTMOD_OUTPUT :=3D $(MO) +endif + $(if $(word 2, $(KBUILD_EXTMOD)), \ $(error building multiple external modules is not supported)) =20 @@ -187,7 +191,7 @@ ifdef KBUILD_EXTMOD else objtree :=3D $(CURDIR) endif - output :=3D $(KBUILD_EXTMOD) + output :=3D $(or $(KBUILD_EXTMOD_OUTPUT),$(KBUILD_EXTMOD)) # KBUILD_EXTMOD might be a relative path. Remember its absolute path b= efore # Make changes the working directory. srcroot :=3D $(realpath $(KBUILD_EXTMOD)) @@ -555,7 +559,7 @@ USERINCLUDE :=3D \ LINUXINCLUDE :=3D \ -I$(srctree)/arch/$(SRCARCH)/include \ -I$(objtree)/arch/$(SRCARCH)/include/generated \ - $(if $(building_out_of_srctree),-I$(srctree)/include) \ + -I$(srctree)/include \ -I$(objtree)/include \ $(USERINCLUDE) =20 @@ -645,6 +649,7 @@ quiet_cmd_makefile =3D GEN Makefile } > Makefile =20 outputmakefile: +ifeq ($(KBUILD_EXTMOD),) @if [ -f $(srctree)/.config -o \ -d $(srctree)/include/config -o \ -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \ @@ -654,7 +659,16 @@ outputmakefile: echo >&2 "***"; \ false; \ fi - $(Q)ln -fsn $(srctree) source +else + @if [ -f $(srcroot)/modules.order ]; then \ + echo >&2 "***"; \ + echo >&2 "*** The external module source tree is not clean."; \ + echo >&2 "*** Please run 'make -C $(abs_srctree) M=3D$(realpath $(srcroo= t)) clean'"; \ + echo >&2 "***"; \ + false; \ + fi +endif + $(Q)ln -fsn $(srcroot) source $(call cmd,makefile) $(Q)test -e .gitignore || \ { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore @@ -1940,6 +1954,8 @@ KBUILD_MODULES :=3D 1 =20 endif =20 +prepare: outputmakefile + # Preset locale variables to speed up the build process. Limit locale # tweaks to this spot to avoid wrong language settings when running # make menuconfig etc. diff --git a/scripts/Makefile.host b/scripts/Makefile.host index e01c13a588dd..c1dedf646a39 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -96,12 +96,10 @@ hostrust_flags =3D --out-dir $(dir $@) --emit=3Ddep-inf= o=3D$(depfile) \ $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \ $(HOSTRUSTFLAGS_$(target-stem)) =20 -# $(objtree)/$(obj) for including generated headers from checkin source fi= les -ifeq ($(KBUILD_EXTMOD),) +# $(obj) for including generated headers from checkin source files ifdef building_out_of_srctree -hostc_flags +=3D -I $(objtree)/$(obj) -hostcxx_flags +=3D -I $(objtree)/$(obj) -endif +hostc_flags +=3D -I $(obj) +hostcxx_flags +=3D -I $(obj) endif =20 ##### diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index e7859ad90224..5660dfc9ed36 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -213,13 +213,11 @@ endif =20 # $(src) for including checkin headers from generated source files # $(obj) for including generated headers from checkin source files -ifeq ($(KBUILD_EXTMOD),) ifdef building_out_of_srctree _c_flags +=3D $(addprefix -I, $(src) $(obj)) _a_flags +=3D $(addprefix -I, $(src) $(obj)) _cpp_flags +=3D $(addprefix -I, $(src) $(obj)) endif -endif =20 # If $(is-kernel-object) is 'y', this object will be linked to vmlinux or = modules is-kernel-object =3D $(or $(part-of-builtin),$(part-of-module)) --=20 2.43.0