From 13b25489b6f8bd73ed65f07928f7c27a481f1820 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 10 Nov 2024 10:34:33 +0900 Subject: kbuild: change working directory to external module directory with M= Currently, Kbuild always operates in the output directory of the kernel, even when building external modules. This increases the risk of external module Makefiles attempting to write to the kernel directory. This commit switches the working directory to the external module directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from some build artifacts. The command for building external modules maintains backward compatibility, but Makefiles that rely on working in the kernel directory may break. In such cases, $(objtree) and $(srctree) should be used to refer to the output and source directories of the kernel. The appearance of the build log will change as follows: [Before] $ make -C /path/to/my/linux M=/path/to/my/externel/module make: Entering directory '/path/to/my/linux' CC [M] /path/to/my/externel/module/helloworld.o MODPOST /path/to/my/externel/module/Module.symvers CC [M] /path/to/my/externel/module/helloworld.mod.o CC [M] /path/to/my/externel/module/.module-common.o LD [M] /path/to/my/externel/module/helloworld.ko make: Leaving directory '/path/to/my/linux' [After] $ make -C /path/to/my/linux M=/path/to/my/externel/module make: Entering directory '/path/to/my/linux' make[1]: Entering directory '/path/to/my/externel/module' CC [M] helloworld.o MODPOST Module.symvers CC [M] helloworld.mod.o CC [M] .module-common.o LD [M] helloworld.ko make[1]: Leaving directory '/path/to/my/externel/module' make: Leaving directory '/path/to/my/linux' Printing "Entering directory" twice is cumbersome. This will be addressed later. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- scripts/Makefile.build | 2 +- scripts/Makefile.clean | 2 +- scripts/Makefile.compiler | 2 +- scripts/Makefile.modpost | 6 +++--- scripts/coccicheck | 6 +----- scripts/nsdeps | 8 +------- scripts/package/install-extmod-build | 7 +++++++ 7 files changed, 15 insertions(+), 18 deletions(-) (limited to 'scripts') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index dd7a80ebca62..e5e382a1d64d 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -3,7 +3,7 @@ # Building # ========================================================================== -src := $(if $(VPATH),$(VPATH)/)$(obj) +src := $(srcroot)/$(obj) PHONY := $(obj)/ $(obj)/: diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean index 4fcfab40ed61..6ead00ec7313 100644 --- a/scripts/Makefile.clean +++ b/scripts/Makefile.clean @@ -3,7 +3,7 @@ # Cleaning up # ========================================================================== -src := $(if $(VPATH),$(VPATH)/)$(obj) +src := $(srcroot)/$(obj) PHONY := __clean __clean: diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler index e0842496d26e..8c1029687e2e 100644 --- a/scripts/Makefile.compiler +++ b/scripts/Makefile.compiler @@ -13,7 +13,7 @@ cc-cross-prefix = $(firstword $(foreach c, $(1), \ $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) # output directory for tests below -TMPOUT = $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_$$$$ +TMPOUT = .tmp_$$$$ # try-run # Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost index 12e7c15d099c..78d2ca4f25f5 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -111,13 +111,13 @@ endif else # set src + obj - they may be used in the modules's Makefile -obj := $(KBUILD_EXTMOD) -src := $(if $(VPATH),$(VPATH)/)$(obj) +obj := . +src := $(srcroot) # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS include $(kbuild-file) -output-symdump := $(KBUILD_EXTMOD)/Module.symvers +output-symdump := Module.symvers ifeq ($(wildcard $(objtree)/Module.symvers),) missing-input := $(objtree)/Module.symvers diff --git a/scripts/coccicheck b/scripts/coccicheck index e52cb43fede6..0e6bc5a10320 100755 --- a/scripts/coccicheck +++ b/scripts/coccicheck @@ -80,11 +80,7 @@ command results in a shift count error.' NPROC=1 else ONLINE=0 - if [ "$KBUILD_EXTMOD" = "" ] ; then - OPTIONS="--dir $srctree $COCCIINCLUDE" - else - OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE" - fi + OPTIONS="--dir $srcroot $COCCIINCLUDE" # Use only one thread per core by default if hyperthreading is enabled THREADS_PER_CORE=$(LANG=C lscpu | grep "Thread(s) per core: " | tr -cd "[:digit:]") diff --git a/scripts/nsdeps b/scripts/nsdeps index f1718cc0d700..8ca12e2b5c03 100644 --- a/scripts/nsdeps +++ b/scripts/nsdeps @@ -19,12 +19,6 @@ if ! { echo "$SPATCH_REQ_VERSION"; echo "$SPATCH_VERSION"; } | sort -CV ; then exit 1 fi -if [ "$KBUILD_EXTMOD" ]; then - src_prefix= -else - src_prefix=$srctree/ -fi - generate_deps_for_ns() { $SPATCH --very-quiet --in-place --sp-file \ $srctree/scripts/coccinelle/misc/add_namespace.cocci -D nsdeps -D ns=$1 $2 @@ -34,7 +28,7 @@ generate_deps() { local mod=${1%.ko:} shift local namespaces="$*" - local mod_source_files=$(sed "s|^\(.*\)\.o$|${src_prefix}\1.c|" $mod.mod) + local mod_source_files=$(sed "s|^\(.*\)\.o$|${srcroot}/\1.c|" $mod.mod) for ns in $namespaces; do echo "Adding namespace $ns to module $mod.ko." diff --git a/scripts/package/install-extmod-build b/scripts/package/install-extmod-build index 7ec1f061a519..64d958ee45f3 100755 --- a/scripts/package/install-extmod-build +++ b/scripts/package/install-extmod-build @@ -51,6 +51,13 @@ mkdir -p "${destdir}" if [ "${CC}" != "${HOSTCC}" ]; then echo "Rebuilding host programs with ${CC}..." + # This leverages external module building. + # - Clear sub_make_done to allow the top-level Makefile to redo sub-make. + # - Filter out --no-print-directory to print "Entering directory" logs + # when Make changes the working directory. + unset sub_make_done + MAKEFLAGS=$(echo "${MAKEFLAGS}" | sed s/--no-print-directory//) + cat <<-'EOF' > "${destdir}/Kbuild" subdir-y := scripts EOF -- cgit v1.2.3