@@ -250,25 +250,17 @@ variables for .cocciconfig is as follows:
- Your directory from which spatch is called is processed next
- The directory provided with the ``--dir`` option is processed last, if used
-Since coccicheck runs through make, it naturally runs from the kernel
-proper dir; as such the second rule above would be implied for picking up a
-.cocciconfig when using ``make coccicheck``.
-
``make coccicheck`` also supports using M= targets. If you do not supply
any M= target, it is assumed you want to target the entire kernel.
The kernel coccicheck script has::
- if [ "$KBUILD_EXTMOD" = "" ] ; then
- OPTIONS="--dir $srctree $COCCIINCLUDE"
- else
- OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE"
- fi
+ OPTIONS="--dir $srcroot $COCCIINCLUDE"
-KBUILD_EXTMOD is set when an explicit target with M= is used. For both cases
-the spatch ``--dir`` argument is used, as such third rule applies when whether
-M= is used or not, and when M= is used the target directory can have its own
-.cocciconfig file. When M= is not passed as an argument to coccicheck the
-target directory is the same as the directory from where spatch was called.
+Here, $srcroot refers to the source directory of the target: it points to the
+external module's source directory when M= used, and otherwise, to the kernel
+source directory. The third rule ensures the spatch reads the .cocciconfig from
+the target directory, allowing external modules to have their own .cocciconfig
+file.
If not using the kernel's coccicheck target, keep the above precedence
order logic of .cocciconfig reading. If using the kernel's coccicheck target,
@@ -449,6 +449,20 @@ $(obj)
to prerequisites are referenced with $(src) (because they are not
generated files).
+$(srcroot)
+ $(srcroot) refers to the root of the source you are building, which can be
+ either the kernel source or the external modules source, depending on whether
+ KBUILD_EXTMOD is set. This can be either a relative or an absolute path, but
+ if KBUILD_ABS_SRCTREE=1 is set, it is always an absolute path.
+
+$(srctree)
+ $(srctree) refers to the root of the kernel source tree. When building the
+ kernel, this is the same as $(srcroot).
+
+$(objtree)
+ $(objtree) refers to the root of the kernel object tree. It is ``.`` when
+ building the kernel, but it is different when building external modules.
+
$(kecho)
echoing information to user in a rule is often a good practice
but when execution ``make -s`` one does not expect to see any output
@@ -180,7 +180,24 @@ ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
-output := $(KBUILD_OUTPUT)
+ifdef KBUILD_EXTMOD
+ ifdef KBUILD_OUTPUT
+ objtree := $(realpath $(KBUILD_OUTPUT))
+ $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
+ else
+ objtree := $(CURDIR)
+ endif
+ output := $(KBUILD_EXTMOD)
+ # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
+ # Make changes the working directory.
+ srcroot := $(realpath $(KBUILD_EXTMOD))
+ $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
+else
+ objtree := .
+ output := $(KBUILD_OUTPUT)
+endif
+
+export objtree srcroot
# Do we want to change the working directory?
ifneq ($(output),)
@@ -230,35 +247,33 @@ else # need-sub-make
# We process the rest of the Makefile if this is the final invocation of make
-ifeq ($(abs_srctree),$(CURDIR))
- # building in the source tree
- srctree := .
- building_out_of_srctree :=
+ifndef KBUILD_EXTMOD
+srcroot := $(abs_srctree)
+endif
+
+ifeq ($(srcroot),$(CURDIR))
+building_out_of_srctree :=
else
- ifeq ($(abs_srctree)/,$(dir $(CURDIR)))
- # building in a subdirectory of the source tree
- srctree := ..
- else
- srctree := $(abs_srctree)
- endif
- building_out_of_srctree := 1
+export building_out_of_srctree :=1
endif
-ifneq ($(KBUILD_ABS_SRCTREE),)
-srctree := $(abs_srctree)
+ifdef KBUILD_ABS_SRCTREE
+ # Do not nothing. Use the absolute path.
+else ifeq ($(srcroot),$(CURDIR))
+ # Building in the source.
+ srcroot := .
+else ifeq ($(srcroot)/,$(dir $(CURDIR)))
+ # Building in a subdirectory of the source.
+ srcroot := ..
endif
-objtree := .
+export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
-VPATH :=
-
-ifeq ($(KBUILD_EXTMOD),)
ifdef building_out_of_srctree
-VPATH := $(srctree)
+export VPATH := $(srcroot)
+else
+VPATH :=
endif
-endif
-
-export building_out_of_srctree srctree objtree VPATH
# To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile
@@ -711,7 +726,7 @@ endif
# in addition to whatever we do anyway.
# Just "make" or "make all" shall build modules as well
-ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps compile_commands.json clang-%,$(MAKECMDGOALS)),)
KBUILD_MODULES := 1
endif
@@ -1107,7 +1122,7 @@ export MODLIB
PHONY += prepare0
-export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
+export extmod_prefix =
export MODORDER := $(extmod_prefix)modules.order
export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
@@ -1799,14 +1814,10 @@ filechk_kernel.release = echo $(KERNELRELEASE)
KBUILD_BUILTIN :=
KBUILD_MODULES := 1
-build-dir := $(KBUILD_EXTMOD)
+build-dir := .
-compile_commands.json: $(extmod_prefix)compile_commands.json
-PHONY += compile_commands.json
-
-clean-dirs := $(KBUILD_EXTMOD)
-clean: private rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
- $(KBUILD_EXTMOD)/compile_commands.json
+clean-dirs := .
+clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
PHONY += prepare
# now expand this into a simple variable to reduce the cost of shell evaluations
@@ -1948,7 +1959,7 @@ $(clean-dirs):
clean: $(clean-dirs)
$(call cmd,rmfiles)
- @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
+ @find . $(RCS_FIND_IGNORE) \
\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
-o -name '*.ko.*' \
-o -name '*.dtb' -o -name '*.dtbo' \
@@ -1981,7 +1992,12 @@ tags TAGS cscope gtags: FORCE
PHONY += rust-analyzer
rust-analyzer:
+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
+ifdef KBUILD_EXTMOD
+# FIXME: external modules must not descend into a sub-directory of the kernel
+ $(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
+else
$(Q)$(MAKE) $(build)=rust $@
+endif
# Script to generate missing namespace dependencies
# ---------------------------------------------------------------------------
@@ -362,8 +362,8 @@ rust-analyzer:
$(Q)$(srctree)/scripts/generate_rust_analyzer.py \
--cfgs='core=$(core-cfgs)' --cfgs='alloc=$(alloc-cfgs)' \
$(realpath $(srctree)) $(realpath $(objtree)) \
- $(rustc_sysroot) $(RUST_LIB_SRC) $(KBUILD_EXTMOD) > \
- $(if $(KBUILD_EXTMOD),$(extmod_prefix),$(objtree))/rust-project.json
+ $(rustc_sysroot) $(RUST_LIB_SRC) $(if $(KBUILD_EXTMOD),$(srcroot)) \
+ > rust-project.json
redirect-intrinsics = \
__addsf3 __eqsf2 __extendsfdf2 __gesf2 __lesf2 __ltsf2 __mulsf3 __nesf2 __truncdfsf2 __unordsf2 \
@@ -3,7 +3,7 @@
# Building
# ==========================================================================
-src := $(if $(VPATH),$(VPATH)/)$(obj)
+src := $(srcroot)/$(obj)
PHONY := $(obj)/
$(obj)/:
@@ -3,7 +3,7 @@
# Cleaning up
# ==========================================================================
-src := $(if $(VPATH),$(VPATH)/)$(obj)
+src := $(srcroot)/$(obj)
PHONY := __clean
__clean:
@@ -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)
@@ -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 := $(objtree)/Module.symvers
@@ -80,11 +80,7 @@ command results in a shift count error.'
NPROC=1
else
ONLINE=0
- if [ "$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:]")
@@ -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 $mod.ko."
@@ -51,6 +51,13 @@ mkdir -p "${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
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 <masahiroy@kernel.org> --- Changes in v2: - Introduce a new 'srcroot' variable and clean-up code - Reword Documentation/dev-tools/coccinelle.rst Documentation/dev-tools/coccinelle.rst | 20 ++----- Documentation/kbuild/makefiles.rst | 14 +++++ Makefile | 80 +++++++++++++++----------- rust/Makefile | 4 +- 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 +++ 11 files changed, 85 insertions(+), 66 deletions(-)