[PATCH 1/8] kbuild: pkg: use -f $(srctree)/Makefile to recurse to top Makefile

[PATCH 1/8] kbuild: pkg: use -f $(srctree)/Makefile to recurse to top Makefile

[Masahiro Yamada]

'$(MAKE) KBUILD_SRC=' changes the working directory back and forth
between objtree and srctree.

It is better to recurse to the top-level Makefile directly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/package/Makefile |  4 ++--
 scripts/package/builddeb | 10 +++++-----
 scripts/package/buildtar |  2 +-
 scripts/package/mkdebian |  6 ++++--
 4 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/scripts/package/Makefile b/scripts/package/Makefile
index 453fece..aa39c2b 100644
--- a/scripts/package/Makefile
+++ b/scripts/package/Makefile
@@ -59,7 +59,7 @@ rpm-pkg: FORCE
 # binrpm-pkg
 # ---------------------------------------------------------------------------
 binrpm-pkg: FORCE
-	$(MAKE) KBUILD_SRC=
+	$(MAKE) -f $(srctree)/Makefile
 	$(CONFIG_SHELL) $(MKSPEC) prebuilt > $(objtree)/binkernel.spec
 	+rpmbuild $(RPMOPTS) --define "_builddir $(objtree)" --target \
 		$(UTS_MACHINE) -bb $(objtree)/binkernel.spec
@@ -102,7 +102,7 @@ clean-dirs += $(objtree)/snap/
 # tarball targets
 # ---------------------------------------------------------------------------
 tar%pkg: FORCE
-	$(MAKE) KBUILD_SRC=
+	$(MAKE) -f $(srctree)/Makefile
 	$(CONFIG_SHELL) $(srctree)/scripts/package/buildtar $@
 
 clean-dirs += $(objtree)/tar-install/
diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index f43a274..8ac25d1 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -86,12 +86,12 @@ cp "$($MAKE -s -f $srctree/Makefile image_name)" "$tmpdir/$installed_image_path"
 if grep -q "^CONFIG_OF_EARLY_FLATTREE=y" $KCONFIG_CONFIG ; then
 	# Only some architectures with OF support have this target
 	if [ -d "${srctree}/arch/$SRCARCH/boot/dts" ]; then
-		$MAKE KBUILD_SRC= INSTALL_DTBS_PATH="$tmpdir/usr/lib/$packagename" dtbs_install
+		$MAKE -f $srctree/Makefile INSTALL_DTBS_PATH="$tmpdir/usr/lib/$packagename" dtbs_install
 	fi
 fi
 
 if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then
-	INSTALL_MOD_PATH="$tmpdir" $MAKE KBUILD_SRC= modules_install
+	INSTALL_MOD_PATH="$tmpdir" $MAKE -f $srctree/Makefile modules_install
 	rm -f "$tmpdir/lib/modules/$version/build"
 	rm -f "$tmpdir/lib/modules/$version/source"
 	if [ "$ARCH" = "um" ] ; then
@@ -113,14 +113,14 @@ if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then
 		# resign stripped modules
 		MODULE_SIG_ALL="$(grep -s '^CONFIG_MODULE_SIG_ALL=y' $KCONFIG_CONFIG || true)"
 		if [ -n "$MODULE_SIG_ALL" ]; then
-			INSTALL_MOD_PATH="$tmpdir" $MAKE KBUILD_SRC= modules_sign
+			INSTALL_MOD_PATH="$tmpdir" $MAKE -f $srctree/Makefile modules_sign
 		fi
 	fi
 fi
 
 if [ "$ARCH" != "um" ]; then
-	$MAKE headers_check KBUILD_SRC=
-	$MAKE headers_install KBUILD_SRC= INSTALL_HDR_PATH="$libc_headers_dir/usr"
+	$MAKE -f $srctree/Makefile headers_check
+	$MAKE -f $srctree/Makefile headers_install INSTALL_HDR_PATH="$libc_headers_dir/usr"
 fi
 
 # Install the maintainer scripts
diff --git a/scripts/package/buildtar b/scripts/package/buildtar
index d624a07..cfd2a4a 100755
--- a/scripts/package/buildtar
+++ b/scripts/package/buildtar
@@ -57,7 +57,7 @@ dirs=boot
 # Try to install modules
 #
 if grep -q '^CONFIG_MODULES=y' "${KCONFIG_CONFIG}"; then
-	make ARCH="${ARCH}" O="${objtree}" KBUILD_SRC= INSTALL_MOD_PATH="${tmpdir}" modules_install
+	make ARCH="${ARCH}" -f ${srctree}/Makefile INSTALL_MOD_PATH="${tmpdir}" modules_install
 	dirs="$dirs lib"
 fi
 
diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index edcad61..f030961 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -205,13 +205,15 @@ EOF
 cat <<EOF > debian/rules
 #!$(command -v $MAKE) -f
 
+srctree ?= .
+
 build:
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
-	KBUILD_BUILD_VERSION=${revision} KBUILD_SRC=
+	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile
 
 binary-arch:
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
-	KBUILD_BUILD_VERSION=${revision} KBUILD_SRC= intdeb-pkg
+	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile intdeb-pkg
 
 clean:
 	rm -rf debian/*tmp debian/files
-- 
2.7.4

[PATCH 2/8] kbuild: generate modules.order only when CONFIG_MODULES=y

[Masahiro Yamada]

Do not generate pointless modules.order when the module support is
disabled.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 scripts/Makefile.build | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 99be01c..89debbe 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -63,7 +63,9 @@ ifneq ($(strip $(real-obj-y) $(need-builtin)),)
 builtin-target := $(obj)/built-in.a
 endif
 
+ifdef CONFIG_MODULES
 modorder-target := $(obj)/modules.order
+endif
 
 # We keep a list of all modules in $(MODVERDIR)
 
-- 
2.7.4

[PATCH 3/8] kbuild: set KBUILD_MODULES=1 all the time for single target %/

[Masahiro Yamada]

It is fine to set KBUILD_MODULES=1 when CONFIG_MODULES is disabled.
It is actually how "make allnoconfig all" works.

On the other hand, KBUILD_MODULES=1 is unneeded for the %.ko pattern.
It is just a matter of whether modules.order is generated or not.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Makefile | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 3cf253d..fe62de3 100644
--- a/Makefile
+++ b/Makefile
@@ -1710,16 +1710,13 @@ endif
 
 # Modules
 /: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
-	$(build)=$(build-dir)
+	$(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
 # Make sure the latest headers are built for Documentation
 Documentation/ samples/: headers_install
 %/: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
-	$(build)=$(build-dir)
+	$(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
 %.ko: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
-	$(build)=$(build-dir) $(@:.ko=.o)
+	$(Q)$(MAKE) $(build)=$(build-dir) $(@:.ko=.o)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 # FIXME Should go into a make.lib or something
-- 
2.7.4

[PATCH 4/8] kbuild: turn '/' into an alias of './'

[Masahiro Yamada]

Commit 06300b21f4c7 ("kbuild: support building individual files for
external modules") introduced the '/' target. It works only for
external modules to build all .o files, but skip the modpost stage.

However, 'make /' looks a bit weird to me. 'make ./' is more sensible
if you want to build all objects under the current directory, and it
works as expected.

Let's change '/' into a phony target that is an alias of './', but
I may feel like deprecating it in the future.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Documentation/kbuild/modules.txt | 2 +-
 Makefile                         | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt
index 3fb39e0..80295c6 100644
--- a/Documentation/kbuild/modules.txt
+++ b/Documentation/kbuild/modules.txt
@@ -140,7 +140,7 @@ executed to make module versioning work.
 		make -C $KDIR M=$PWD bar.lst
 		make -C $KDIR M=$PWD baz.o
 		make -C $KDIR M=$PWD foo.ko
-		make -C $KDIR M=$PWD /
+		make -C $KDIR M=$PWD ./
 
 
 === 3. Creating a Kbuild File for an External Module
diff --git a/Makefile b/Makefile
index fe62de3..3956e93 100644
--- a/Makefile
+++ b/Makefile
@@ -1709,8 +1709,9 @@ endif
 	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
 
 # Modules
-/: prepare FORCE
-	$(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
+PHONY += /
+/: ./
+
 # Make sure the latest headers are built for Documentation
 Documentation/ samples/: headers_install
 %/: prepare FORCE
-- 
2.7.4

[PATCH 5/8] kbuild: move tools_silent to a more relevant place

[Masahiro Yamada]

This would disturb the change the sub-make part. Move it near the
tools/ target.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Makefile | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 3956e93..0180b23 100644
--- a/Makefile
+++ b/Makefile
@@ -90,7 +90,6 @@ endif
 
 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
   quiet=silent_
-  tools_silent=s
 endif
 
 export quiet Q KBUILD_VERBOSE
@@ -1664,6 +1663,11 @@ image_name:
 	@echo $(KBUILD_IMAGE)
 
 # Clear a bunch of variables before executing the submake
+
+ifeq ($(quiet),silent_)
+tools_silent=s
+endif
+
 tools/: FORCE
 	$(Q)mkdir -p $(objtree)/tools
 	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/
-- 
2.7.4

[PATCH 6/8] kbuild: make -r/-R effective in top Makefile for old Make versions

[Masahiro Yamada]

Adding -rR to MAKEFLAGS is important because we do not want to
be bothered by built-in implicit rules or variables.

One problem that used to exist in older GNU Make versions is

  MAKEFLAGS += -rR

... does not become effective in the current Makefile. When you are
building with O= option, it becomes effective in the top Makefile
since it recurses via 'sub-make' target. Otherwise, the top Makefile
tries implicit rules. That is why we explicitly add empty rules for
Makefiles, but we often miss to do that.

In fact, adding -d option to older GNU Make versions shows it is
trying a bunch of implicit pattern rules.

 Considering target file `scripts/Makefile.kcov'.
  Looking for an implicit rule for `scripts/Makefile.kcov'.
  Trying pattern rule with stem `Makefile.kcov'.
  Trying implicit prerequisite `scripts/Makefile.kcov.o'.
  Trying pattern rule with stem `Makefile.kcov'.
  Trying implicit prerequisite `scripts/Makefile.kcov.c'.
  Trying pattern rule with stem `Makefile.kcov'.
  Trying implicit prerequisite `scripts/Makefile.kcov.cc'.
  Trying pattern rule with stem `Makefile.kcov'.
  Trying implicit prerequisite `scripts/Makefile.kcov.C'.
  ...

This issue was fixed by GNU Make commit 58dae243526b ("[Savannah #20501]
Handle adding -r/-R to MAKEFLAGS in the makefile"). So, it is no longer
a problem if you use GNU Make 4.0 or later. However, older versions are
still widely used.

So, I decided to patch the kernel Makefile to invoke sub-make regardless
of O= option. This will allow further cleanups.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Makefile | 48 ++++++++++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/Makefile b/Makefile
index 0180b23..25d7d46 100644
--- a/Makefile
+++ b/Makefile
@@ -15,19 +15,6 @@ NAME = Shy Crocodile
 PHONY := _all
 _all:
 
-# Do not use make's built-in rules and variables
-# (this increases performance and avoids hard-to-debug behaviour)
-MAKEFLAGS += -rR
-
-# Avoid funny character set dependencies
-unexport LC_ALL
-LC_COLLATE=C
-LC_NUMERIC=C
-export LC_COLLATE LC_NUMERIC
-
-# Avoid interference with shell env settings
-unexport GREP_OPTIONS
-
 # We are using a recursive build, so we need to do a little thinking
 # to get the ordering right.
 #
@@ -44,6 +31,21 @@ unexport GREP_OPTIONS
 # descending is started. They are now explicitly listed as the
 # prepare rule.
 
+ifndef KBUILD_SUBMAKE
+
+# Do not use make's built-in rules and variables
+# (this increases performance and avoids hard-to-debug behaviour)
+MAKEFLAGS += -rR
+
+# Avoid funny character set dependencies
+unexport LC_ALL
+LC_COLLATE=C
+LC_NUMERIC=C
+export LC_COLLATE LC_NUMERIC
+
+# Avoid interference with shell env settings
+unexport GREP_OPTIONS
+
 # Beautify output
 # ---------------------------------------------------------------------------
 #
@@ -111,7 +113,6 @@ export quiet Q KBUILD_VERBOSE
 
 # KBUILD_SRC is not intended to be used by the regular user (for now),
 # it is set on invocation of make with KBUILD_OUTPUT or O= specified.
-ifeq ($(KBUILD_SRC),)
 
 # OK, Make called in directory where kernel src resides
 # Do we want to locate output files in a separate directory?
@@ -141,6 +142,13 @@ $(if $(KBUILD_OUTPUT),, \
 # 'sub-make' below.
 MAKEFLAGS += --include-dir=$(CURDIR)
 
+else
+
+# Do not print "Entering directory ..." at all for in-tree build.
+MAKEFLAGS += --no-print-directory
+
+endif # ifneq ($(KBUILD_OUTPUT),)
+
 PHONY += $(MAKECMDGOALS) sub-make
 
 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
@@ -148,16 +156,12 @@ $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 
 # Invoke a second make in the output directory, passing relevant variables
 sub-make:
-	$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
+	$(Q)$(MAKE) KBUILD_SUBMAKE=1 \
+	$(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
 	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
 
-# Leave processing to above invocation of make
-skip-makefile := 1
-endif # ifneq ($(KBUILD_OUTPUT),)
-endif # ifeq ($(KBUILD_SRC),)
-
+else # KBUILD_SUBMAKE
 # We process the rest of the Makefile if this is the final invocation of make
-ifeq ($(skip-makefile),)
 
 # Do not print "Entering directory ...",
 # but we want to display it when entering to the output directory
@@ -1752,7 +1756,7 @@ $(cmd_files): ;	# Do not try to update included dependency files
 
 endif   # ifeq ($(config-targets),1)
 endif   # ifeq ($(mixed-targets),1)
-endif	# skip-makefile
+endif	# ifndef KBUILD_SUBMAKE
 
 PHONY += FORCE
 FORCE:
-- 
2.7.4

[PATCH 7/8] kbuild: remove empty rules for makefiles

[Masahiro Yamada]

The previous commit made 'MAKEFLAGS += -rR' effective in the top
Makefile regardless of O= option, GNU Make versions.

The top Makefile does not need to cancel implicit rules for makefiles.

There is still one place where an empty rule is useful. Since -rR is
effective only after sub-make, GNU Make would try implicit rules to
update the top Makefile. Although it is not a big overhead, cancel
it just in case.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Makefile | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/Makefile b/Makefile
index 25d7d46..f7f1aa1 100644
--- a/Makefile
+++ b/Makefile
@@ -37,6 +37,10 @@ ifndef KBUILD_SUBMAKE
 # (this increases performance and avoids hard-to-debug behaviour)
 MAKEFLAGS += -rR
 
+# 'MAKEFLAGS += -rR' does not become immediately effective for old
+# GNU Make versions. Cancel implicit rules for this Makefile.
+$(lastword $(MAKEFILE_LIST)): ;
+
 # Avoid funny character set dependencies
 unexport LC_ALL
 LC_COLLATE=C
@@ -120,9 +124,6 @@ ifeq ("$(origin O)", "command line")
   KBUILD_OUTPUT := $(O)
 endif
 
-# Cancel implicit rules on top Makefile
-$(CURDIR)/Makefile Makefile: ;
-
 ifneq ($(words $(subst :, ,$(CURDIR))), 1)
   $(error main directory cannot contain spaces nor colons)
 endif
@@ -303,8 +304,6 @@ __build_one_by_one:
 
 else
 
-# We need some generic definitions (do not try to remake the file).
-scripts/Kbuild.include: ;
 include scripts/Kbuild.include
 
 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
@@ -627,9 +626,6 @@ ifeq ($(may-sync-config),1)
 # because some architectures define CROSS_COMPILE there.
 -include include/config/auto.conf.cmd
 
-# To avoid any implicit rule to kick in, define an empty command
-$(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
-
 # The actual configuration files used during the build are stored in
 # include/generated/ and include/config/. Update them if .config is newer than
 # include/config/auto.conf (which mirrors .config).
@@ -1750,9 +1746,7 @@ cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
 # read saved command lines for existing targets
 existing-targets := $(wildcard $(sort $(targets)))
 
-cmd_files := $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
-$(cmd_files): ;	# Do not try to update included dependency files
--include $(cmd_files)
+-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
 
 endif   # ifeq ($(config-targets),1)
 endif   # ifeq ($(mixed-targets),1)
-- 
2.7.4

[PATCH 8/8] kbuild: simplify single targets

[Masahiro Yamada]

The dependency will be checked anyway after Kbuild descends into a
sub-directory. Skip object/source dependency checks in top Makefile.

VPATH can be simpler since the top Makefile no longer checks the
preprense of the source file, which is located in in the external
module directory.

[Pros]

- Code is cleaner

- It can compile an object from a generated source file

For example,

  $ make crypto/rsapubkey.asn1.o
    ...
  ASN.1   crypto/rsapubkey.asn1.c
  CC      crypto/rsapubkey.asn1.o

[Cons]

- The top Makefile does not let it fail immediately when a user tries
  to build a wrong object.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 Makefile | 38 +++++++++-----------------------------
 1 file changed, 9 insertions(+), 29 deletions(-)

diff --git a/Makefile b/Makefile
index f7f1aa1..8bf0ed6 100644
--- a/Makefile
+++ b/Makefile
@@ -219,7 +219,7 @@ objtree		:= .
 src		:= $(srctree)
 obj		:= $(objtree)
 
-VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
+VPATH		:= $(srctree)
 
 export srctree objtree VPATH
 
@@ -1686,31 +1686,14 @@ tools/%: FORCE
 #  target-dir => where to store outputfile
 #  build-dir  => directory in kernel source tree to use
 
-ifeq ($(KBUILD_EXTMOD),)
-        build-dir  = $(patsubst %/,%,$(dir $@))
-        target-dir = $(dir $@)
-else
-        zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
-        build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
-        target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
-endif
-
-%.s: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.i: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.o: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.lst: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.s: %.S prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.o: %.S prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.symtypes: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
-%.ll: %.c prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+build-target = $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD)/)$@
+build-dir = $(patsubst %/,%,$(dir $(build-target)))
+
+%.i %.ll %.lst %.o %.s %.symtypes: prepare FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(build-target)
+
+%.ko: %.o
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 # Modules
 PHONY += /
@@ -1720,9 +1703,6 @@ PHONY += /
 Documentation/ samples/: headers_install
 %/: prepare FORCE
 	$(Q)$(MAKE) KBUILD_MODULES=1 $(build)=$(build-dir)
-%.ko: prepare FORCE
-	$(Q)$(MAKE) $(build)=$(build-dir) $(@:.ko=.o)
-	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 # FIXME Should go into a make.lib or something
 # ===========================================================================
-- 
2.7.4

Re: [PATCH 1/8] kbuild: pkg: use -f $(srctree)/Makefile to recurse to top Makefile

[Masahiro Yamada]

On Thu, Feb 14, 2019 at 7:41 PM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> '$(MAKE) KBUILD_SRC=' changes the working directory back and forth
> between objtree and srctree.
>
> It is better to recurse to the top-level Makefile directly.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---

Patch 1/8 - 4/8 applied to linux-kbuild.

I will send v2 for the rest
because I noticed some issues.


-- 
Best Regards
Masahiro Yamada