From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from conuserg-09.nifty.com ([210.131.2.76]:19691 "EHLO conuserg-09.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728008AbgEXPnX (ORCPT ); Sun, 24 May 2020 11:43:23 -0400 From: Masahiro Yamada Subject: [PATCH v2 09/29] kbuild: disallow multi-word in M= or KBUILD_EXTMOD Date: Mon, 25 May 2020 00:42:15 +0900 Message-Id: <20200524154235.380482-10-masahiroy@kernel.org> In-Reply-To: <20200524154235.380482-1-masahiroy@kernel.org> References: <20200524154235.380482-1-masahiroy@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Michal Marek , linux-kernel@vger.kernel.org $(firstword ...) in scripts/Makefile.modpost was added by commit 3f3fd3c05585 ("[PATCH] kbuild: allow multi-word $M in Makefile.modpost") to build multiple external module directories. It was a solution to resolve symbol dependencies when an external module depends on another external module. Commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS") introduced another solution by passing symbol info via KBUILD_EXTRA_SYMBOLS, then broke the multi-word M= support. include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) ... does not work if KBUILD_EXTMOD contains multiple words. This feature has been broken for more than a decade. Remove the bitrotten code, and stop parsing if M or KBUILD_EXTMOD contains multiple words. As Documentation/kbuild/modules.rst explains, if your module depends on another one, there are two solutions: - add a common top-level Kbuild file - use KBUILD_EXTRA_SYMBOLS Signed-off-by: Masahiro Yamada --- Changes in v2: - Add more commit log Makefile | 3 +++ scripts/Makefile.modpost | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 72eb55a36545..48a2dfaf3bf3 100644 --- a/Makefile +++ b/Makefile @@ -218,6 +218,9 @@ ifeq ("$(origin M)", "command line") KBUILD_EXTMOD := $(M) endif +$(if $(word 2, $(KBUILD_EXTMOD)), \ + $(error building multiple external modules is not supported)) + export KBUILD_CHECKSRC KBUILD_EXTMOD extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 957eed6a17a5..b79bf0e30d32 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -44,7 +44,7 @@ include include/config/auto.conf include scripts/Kbuild.include kernelsymfile := $(objtree)/Module.symvers -modulesymfile := $(firstword $(KBUILD_EXTMOD))/Module.symvers +modulesymfile := $(KBUILD_EXTMOD)/Module.symvers MODPOST = scripts/mod/modpost \ $(if $(CONFIG_MODVERSIONS),-m) \ -- 2.25.1