Merge tag 'kbuild-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - remove unneeded asm headers from hexagon, ia64

 - add 'dir-pkg' target, which works like 'tar-pkg' but skips archiving

 - add 'helpnewconfig' target, which shows help for new CONFIG options

 - support 'make nsdeps' for external modules

 - make rebuilds faster by deleting $(wildcard $^) checks

 - remove compile tests for kernel-space headers

 - refactor modpost to simplify modversion handling

 - make single target builds faster

 - optimize and clean up scripts/kallsyms.c

 - refactor various Makefiles and scripts

* tag 'kbuild-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (59 commits)
  MAINTAINERS: update Kbuild/Kconfig maintainer's email address
  scripts/kallsyms: remove redundant initializers
  scripts/kallsyms: put check_symbol_range() calls close together
  scripts/kallsyms: make check_symbol_range() void function
  scripts/kallsyms: move ignored symbol types to is_ignored_symbol()
  scripts/kallsyms: move more patterns to the ignored_prefixes array
  scripts/kallsyms: skip ignored symbols very early
  scripts/kallsyms: add const qualifiers where possible
  scripts/kallsyms: make find_token() return (unsigned char *)
  scripts/kallsyms: replace prefix_underscores_count() with strspn()
  scripts/kallsyms: add sym_name() to mitigate cast ugliness
  scripts/kallsyms: remove unneeded length check for prefix matching
  scripts/kallsyms: remove redundant is_arm_mapping_symbol()
  scripts/kallsyms: set relative_base more effectively
  scripts/kallsyms: shrink table before sorting it
  scripts/kallsyms: fix definitely-lost memory leak
  scripts/kallsyms: remove unneeded #ifndef ARRAY_SIZE
  kbuild: make single target builds even faster
  modpost: respect the previous export when 'exported twice' is warned
  modpost: do not set ->preloaded for symbols from Module.symvers
  ...

Author: torvalds

.gitignore

@@ -32,7 +32,6 @@
 *.lzo
 *.mod
 *.mod.c
-*.ns_deps
 *.o
 *.o.*
 *.patch
@@ -61,6 +60,7 @@ modules.order
 /System.map
 /Module.markers
 /modules.builtin.modinfo
+/modules.nsdeps
 
 #
 # RPM spec file (make rpm-pkg)

Documentation/Makefile

@@ -128,8 +128,10 @@ dochelp:
 	@echo  '  pdfdocs         - PDF'
 	@echo  '  epubdocs        - EPUB'
 	@echo  '  xmldocs         - XML'
-	@echo  '  linkcheckdocs   - check for broken external links (will connect to external hosts)'
-	@echo  '  refcheckdocs    - check for references to non-existing files under Documentation'
+	@echo  '  linkcheckdocs   - check for broken external links'
+	@echo  '                    (will connect to external hosts)'
+	@echo  '  refcheckdocs    - check for references to non-existing files under'
+	@echo  '                    Documentation'
 	@echo  '  cleandocs       - clean all generated files'
 	@echo
 	@echo  '  make SPHINXDIRS="s1 s2" [target] Generate only docs of folder s1, s2'

Documentation/core-api/symbol-namespaces.rst

@@ -152,3 +152,6 @@ in-tree modules::
 	- notice the warning of modpost telling about a missing import
 	- run `make nsdeps` to add the import to the correct code location
 
+You can also run nsdeps for external module builds. A typical usage is::
+
+	$ make -C <path_to_kernel_src> M=$PWD nsdeps

Documentation/dontdiff

@@ -179,6 +179,7 @@ mkutf8data
 modpost
 modules.builtin
 modules.builtin.modinfo
+modules.nsdeps
 modules.order
 modversions.h*
 nconf

Documentation/kbuild/makefiles.rst

@@ -1115,23 +1115,6 @@ When kbuild executes, the following steps are followed (roughly):
 	In this example, extra-y is used to list object files that
 	shall be built, but shall not be linked as part of built-in.a.
 
-    header-test-y
-
-	header-test-y specifies headers (`*.h`) in the current directory that
-	should be compile tested to ensure they are self-contained,
-	i.e. compilable as standalone units. If CONFIG_HEADER_TEST is enabled,
-	this builds them as part of extra-y.
-
-    header-test-pattern-y
-
-	This works as a weaker version of header-test-y, and accepts wildcard
-	patterns. The typical usage is::
-
-		header-test-pattern-y += *.h
-
-	This specifies all the files that matches to `*.h` in the current
-	directory, but the files in 'header-test-' are excluded.
-
 6.7 Commands useful for building a boot image
 ---------------------------------------------
 

Documentation/kbuild/modules.rst

@@ -492,19 +492,16 @@ build.
 	to the symbols from the kernel to check if all external symbols
 	are defined. This is done in the MODPOST step. modpost obtains
 	the symbols by reading Module.symvers from the kernel source
-	tree. If a Module.symvers file is present in the directory
-	where the external module is being built, this file will be
-	read too. During the MODPOST step, a new Module.symvers file
-	will be written containing all exported symbols that were not
-	defined in the kernel.
+	tree. During the MODPOST step, a new Module.symvers file will be
+	written containing all exported symbols from that external module.
 
 6.3 Symbols From Another External Module
 ----------------------------------------
 
 	Sometimes, an external module uses exported symbols from
 	another external module. Kbuild needs to have full knowledge of
 	all symbols to avoid spitting out warnings about undefined
-	symbols. Three solutions exist for this situation.
+	symbols. Two solutions exist for this situation.
 
 	NOTE: The method with a top-level kbuild file is recommended
 	but may be impractical in certain situations.
@@ -544,8 +541,8 @@ build.
 		all symbols defined and not part of the kernel.
 
 	Use "make" variable KBUILD_EXTRA_SYMBOLS
-		If it is impractical to copy Module.symvers from
-		another module, you can assign a space separated list
+		If it is impractical to add a top-level kbuild file,
+		you can assign a space separated list
 		of files to KBUILD_EXTRA_SYMBOLS in your build file.
 		These files will be loaded by modpost during the
 		initialization of its symbol tables.

MAINTAINERS

@@ -8934,7 +8934,7 @@ F:	mm/kasan/
 F:	scripts/Makefile.kasan
 
 KCONFIG
-M:	Masahiro Yamada <[email protected]>
+M:	Masahiro Yamada <[email protected]>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kconfig
 L:	[email protected]
 S:	Maintained
@@ -8966,7 +8966,7 @@ S:	Maintained
 F:	fs/autofs/
 
 KERNEL BUILD + files below scripts/ (unless maintained elsewhere)
-M:	Masahiro Yamada <[email protected]>
+M:	Masahiro Yamada <[email protected]>
 M:	Michal Marek <[email protected]>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
 L:	[email protected]

Makefile

@@ -618,7 +618,6 @@ ifeq ($(KBUILD_EXTMOD),)
 init-y		:= init/
 drivers-y	:= drivers/ sound/
 drivers-$(CONFIG_SAMPLES) += samples/
-drivers-$(CONFIG_KERNEL_HEADER_TEST) += include/
 net-y		:= net/
 libs-y		:= lib/
 core-y		:= usr/
@@ -1011,6 +1010,7 @@ endif
 PHONY += prepare0
 
 export MODORDER := $(extmod-prefix)modules.order
+export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
 
 ifeq ($(KBUILD_EXTMOD),)
 core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
@@ -1196,19 +1196,15 @@ headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
 	$(Q)$(MAKE) $(hdr-inst)=include/uapi
 	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
 
+# Deprecated. It is no-op now.
 PHONY += headers_check
-headers_check: headers
-	$(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
-	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi HDRCHECK=1
+headers_check:
+	@:
 
 ifdef CONFIG_HEADERS_INSTALL
 prepare: headers
 endif
 
-ifdef CONFIG_HEADERS_CHECK
-all: headers_check
-endif
-
 PHONY += scripts_unifdef
 scripts_unifdef: scripts_basic
 	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
@@ -1360,7 +1356,7 @@ endif # CONFIG_MODULES
 
 # Directories & files removed with 'make clean'
 CLEAN_DIRS  += include/ksym
-CLEAN_FILES += modules.builtin.modinfo
+CLEAN_FILES += modules.builtin.modinfo modules.nsdeps
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_DIRS  += include/config include/generated          \
@@ -1476,7 +1472,6 @@ help:
 	@echo  '  versioncheck    - Sanity check on version.h usage'
 	@echo  '  includecheck    - Check for duplicate included header files'
 	@echo  '  export_report   - List the usages of all exported symbols'
-	@echo  '  headers_check   - Sanity check on exported headers'
 	@echo  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
 	@echo  ''
@@ -1515,7 +1510,7 @@ help:
 	@echo  ''
 	@$(if $(boards), \
 		$(foreach b, $(boards), \
-		printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
+		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
 		echo '')
 	@$(if $(board-dirs), \
 		$(foreach b, $(board-dirs), \
@@ -1526,7 +1521,8 @@ help:
 	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
 	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
 	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
-	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK (sparse by default)'
+	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
+	@echo  '                       (sparse by default)'
 	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
 	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
 	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
@@ -1622,7 +1618,7 @@ _emodinst_post: _emodinst_
 	$(call cmd,depmod)
 
 clean-dirs := $(KBUILD_EXTMOD)
-clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
+clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps
 
 PHONY += /
 /:
@@ -1641,6 +1637,50 @@ help:
 PHONY += prepare
 endif # KBUILD_EXTMOD
 
+# Single targets
+# ---------------------------------------------------------------------------
+# To build individual files in subdirectories, you can do like this:
+#
+#   make foo/bar/baz.s
+#
+# The supported suffixes for single-target are listed in 'single-targets'
+#
+# To build only under specific subdirectories, you can do like this:
+#
+#   make foo/bar/baz/
+
+ifdef single-build
+
+# .ko is special because modpost is needed
+single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
+single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
+
+$(single-ko): single_modpost
+	@:
+$(single-no-ko): descend
+	@:
+
+ifeq ($(KBUILD_EXTMOD),)
+# For the single build of in-tree modules, use a temporary file to avoid
+# the situation of modules_install installing an invalid modules.order.
+MODORDER := .modules.tmp
+endif
+
+PHONY += single_modpost
+single_modpost: $(single-no-ko)
+	$(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+
+KBUILD_MODULES := 1
+
+export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
+
+# trim unrelated directories
+build-dirs := $(foreach d, $(build-dirs), \
+			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
+
+endif
+
 # Handle descending into subdirectories listed in $(build-dirs)
 # Preset locale variables to speed up the build process. Limit locale
 # tweaks to this spot to avoid wrong language settings when running
@@ -1649,7 +1689,9 @@ endif # KBUILD_EXTMOD
 PHONY += descend $(build-dirs)
 descend: $(build-dirs)
 $(build-dirs): prepare
-	$(Q)$(MAKE) $(build)=$@ single-build=$(single-build) need-builtin=1 need-modorder=1
+	$(Q)$(MAKE) $(build)=$@ \
+	single-build=$(if $(filter-out $@/, $(single-no-ko)),1) \
+	need-builtin=1 need-modorder=1
 
 clean-dirs := $(addprefix _clean_, $(clean-dirs))
 PHONY += $(clean-dirs) clean
@@ -1664,7 +1706,7 @@ clean: $(clean-dirs)
 		-o -name '*.ko.*' \
 		-o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
 		-o -name '*.dwo' -o -name '*.lst' \
-		-o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \
+		-o -name '*.su' -o -name '*.mod' \
 		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
 		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
 		-o -name '*.asn1.[ch]' \
@@ -1686,10 +1728,9 @@ tags TAGS cscope gtags: FORCE
 # ---------------------------------------------------------------------------
 
 PHONY += nsdeps
-
+nsdeps: export KBUILD_NSDEPS=1
 nsdeps: modules
-	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
 
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
@@ -1753,50 +1794,6 @@ tools/%: FORCE
 	$(Q)mkdir -p $(objtree)/tools
 	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
 
-# Single targets
-# ---------------------------------------------------------------------------
-# To build individual files in subdirectories, you can do like this:
-#
-#   make foo/bar/baz.s
-#
-# The supported suffixes for single-target are listed in 'single-targets'
-#
-# To build only under specific subdirectories, you can do like this:
-#
-#   make foo/bar/baz/
-
-ifdef single-build
-
-single-all := $(filter $(single-targets), $(MAKECMDGOALS))
-
-# .ko is special because modpost is needed
-single-ko := $(sort $(filter %.ko, $(single-all)))
-single-no-ko := $(sort $(patsubst %.ko,%.mod, $(single-all)))
-
-$(single-ko): single_modpost
-	@:
-$(single-no-ko): descend
-	@:
-
-ifeq ($(KBUILD_EXTMOD),)
-# For the single build of in-tree modules, use a temporary file to avoid
-# the situation of modules_install installing an invalid modules.order.
-MODORDER := .modules.tmp
-endif
-
-PHONY += single_modpost
-single_modpost: $(single-no-ko)
-	$(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
-	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
-
-KBUILD_MODULES := 1
-
-export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
-
-single-build = $(if $(filter-out $@/, $(single-no-ko)),1)
-
-endif
-
 # FIXME Should go into a make.lib or something
 # ===========================================================================