Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Remove the deprecated rule to build *.dtbo from *.dts

 - Refactor section mismatch detection in modpost

 - Fix bogus ARM section mismatch detections

 - Fix error of 'make gtags' with O= option

 - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
   with the latest LLVM version

 - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed

 - Ignore more compiler-generated symbols for kallsyms

 - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles

 - Enable more kernel-doc warnings with W=2

 - Refactor <linux/export.h> by generating KSYMTAB data by modpost

 - Deprecate <asm/export.h> and <asm-generic/export.h>

 - Remove the EXPORT_DATA_SYMBOL macro

 - Move the check for static EXPORT_SYMBOL back to modpost, which makes
   the build faster

 - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm

 - Warn missing MODULE_DESCRIPTION when building modules with W=1

 - Make 'make clean' robust against too long argument error

 - Exclude more objects from GCOV to fix CFI failures with GCOV

 - Allow 'make modules_install' to install modules.builtin and
   modules.builtin.modinfo even when CONFIG_MODULES is disabled

 - Include modules.builtin and modules.builtin.modinfo in the
   linux-image Debian package even when CONFIG_MODULES is disabled

 - Revive "Entering directory" logging for the latest Make version

* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
  modpost: define more R_ARM_* for old distributions
  kbuild: revive "Entering directory" for Make >= 4.4.1
  kbuild: set correct abs_srctree and abs_objtree for package builds
  scripts/mksysmap: Ignore prefixed KCFI symbols
  kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
  kbuild: builddeb: always make modules_install, to install modules.builtin*
  modpost: continue even with unknown relocation type
  modpost: factor out Elf_Sym pointer calculation to section_rel()
  modpost: factor out inst location calculation to section_rel()
  kbuild: Disable GCOV for *.mod.o
  kbuild: Fix CFI failures with GCOV
  kbuild: make clean rule robust against too long argument error
  script: modpost: emit a warning when the description is missing
  kbuild: make modules_install copy modules.builtin(.modinfo)
  linux/export.h: rename 'sec' argument to 'license'
  modpost: show offset from symbol for section mismatch warnings
  modpost: merge two similar section mismatch warnings
  kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
  modpost: use null string instead of NULL pointer for default namespace
  modpost: squash sym_update_namespace() into sym_add_exported()
  ...

.gitignore

@@ -51,7 +51,6 @@
 *.symversions
 *.tab.[ch]
 *.tar
-*.usyms
 *.xz
 *.zst
 Module.symvers
@@ -112,7 +111,6 @@ modules.order
 #
 /include/config/
 /include/generated/
-/include/ksym/
 /arch/*/include/generated/
 
 # stgit generated dirs

Documentation/kbuild/kbuild.rst

@@ -150,6 +150,12 @@ the UTS_MACHINE variable, and on some architectures also the kernel config.
 The value of KBUILD_DEBARCH is assumed (not checked) to be a valid Debian
 architecture.
 
+KDOCFLAGS
+---------
+Specify extra (warning/error) flags for kernel-doc checks during the build,
+see scripts/kernel-doc for which flags are supported. Note that this doesn't
+(currently) apply to documentation builds.
+
 ARCH
 ----
 Set ARCH to the architecture to be built.

Documentation/process/changes.rst

@@ -60,6 +60,8 @@ openssl & libcrypto    1.0.0            openssl version
 bc                     1.06.95          bc --version
 Sphinx\ [#f1]_         1.7              sphinx-build --version
 cpio                   any              cpio --version
+GNU tar                1.28             tar --version
+gtags (optional)       6.6.5            gtags --version
 ====================== ===============  ========================================
 
 .. [#f1] Sphinx is needed only to build the Kernel documentation
@@ -174,6 +176,18 @@ You will need openssl to build kernels 3.7 and higher if module signing is
 enabled.  You will also need openssl development packages to build kernels 4.3
 and higher.
 
+Tar
+---
+
+GNU tar is needed if you want to enable access to the kernel headers via sysfs
+(CONFIG_IKHEADERS).
+
+gtags / GNU GLOBAL (optional)
+-----------------------------
+
+The kernel build requires GNU GLOBAL version 6.6.5 or later to generate
+tag files through ``make gtags``.  This is due to its use of the gtags
+``-C (--directory)`` flag.
 
 System utilities
 ****************

Makefile

@@ -38,6 +38,10 @@ __all:
 # descending is started. They are now explicitly listed as the
 # prepare rule.
 
+this-makefile := $(lastword $(MAKEFILE_LIST))
+export abs_srctree := $(realpath $(dir $(this-makefile)))
+export abs_objtree := $(CURDIR)
+
 ifneq ($(sub_make_done),1)
 
 # Do not use make's built-in rules and variables
@@ -185,20 +189,8 @@ $(if $(abs_objtree),, \
 
 # $(realpath ...) resolves symlinks
 abs_objtree := $(realpath $(abs_objtree))
-else
-abs_objtree := $(CURDIR)
 endif # ifneq ($(KBUILD_OUTPUT),)
 
-ifeq ($(abs_objtree),$(CURDIR))
-# Suppress "Entering directory ..." unless we are changing the work directory.
-MAKEFLAGS += --no-print-directory
-else
-need-sub-make := 1
-endif
-
-this-makefile := $(lastword $(MAKEFILE_LIST))
-abs_srctree := $(realpath $(dir $(this-makefile)))
-
 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 $(error source directory cannot contain spaces or colons)
 endif
@@ -211,9 +203,25 @@ need-sub-make := 1
 $(this-makefile): ;
 endif
 
-export abs_srctree abs_objtree
 export sub_make_done := 1
 
+endif # sub_make_done
+
+ifeq ($(abs_objtree),$(CURDIR))
+# Suppress "Entering directory ..." if we are at the final work directory.
+no-print-directory := --no-print-directory
+else
+# Recursion to show "Entering directory ..."
+need-sub-make := 1
+endif
+
+ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
+# If --no-print-directory is unset, recurse once again to set it.
+# You may end up recursing into __sub-make twice. This is needed due to the
+# behavior change in GNU Make 4.4.1.
+need-sub-make := 1
+endif
+
 ifeq ($(need-sub-make),1)
 
 PHONY += $(MAKECMDGOALS) __sub-make
@@ -223,18 +231,12 @@ $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 
 # Invoke a second make in the output directory, passing relevant variables
 __sub-make:
-	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
+	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
+	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 
-endif # need-sub-make
-endif # sub_make_done
+else # need-sub-make
 
 # We process the rest of the Makefile if this is the final invocation of make
-ifeq ($(need-sub-make),)
-
-# Do not print "Entering directory ...",
-# but we want to display it when entering to the output directory
-# so that IDEs/editors are able to understand relative filenames.
-MAKEFLAGS += --no-print-directory
 
 ifeq ($(abs_srctree),$(abs_objtree))
         # building in the source tree
@@ -1199,28 +1201,12 @@ endif
 export KBUILD_VMLINUX_LIBS
 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
 
-# Recurse until adjust_autoksyms.sh is satisfied
-PHONY += autoksyms_recursive
 ifdef CONFIG_TRIM_UNUSED_KSYMS
 # For the kernel to actually contain only the needed exported symbols,
 # we have to build modules as well to determine what those symbols are.
-# (this can be evaluated only once include/config/auto.conf has been included)
 KBUILD_MODULES := 1
-
-autoksyms_recursive: $(build-dir) modules.order
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
-	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
 endif
 
-autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
-
-quiet_cmd_autoksyms_h = GEN     $@
-      cmd_autoksyms_h = mkdir -p $(dir $@); \
-			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
-
-$(autoksyms_h):
-	$(call cmd,autoksyms_h)
-
 # '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
 quiet_cmd_ar_vmlinux.a = AR      $@
       cmd_ar_vmlinux.a = \
@@ -1229,7 +1215,7 @@ quiet_cmd_ar_vmlinux.a = AR      $@
 	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
 
 targets += vmlinux.a
-vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
+vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
 	$(call if_changed,ar_vmlinux.a)
 
 PHONY += vmlinux_o
@@ -1285,7 +1271,7 @@ scripts: scripts_basic scripts_dtc
 PHONY += prepare archprepare
 
 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
-	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
+	asm-generic $(version_h) include/generated/utsrelease.h \
 	include/generated/compile.h include/generated/autoconf.h remove-stale-files
 
 prepare0: archprepare
@@ -1567,6 +1553,8 @@ modules_sign_only := y
 endif
 endif
 
+endif # CONFIG_MODULES
+
 modinst_pre :=
 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 modinst_pre := __modinst_pre
@@ -1577,18 +1565,18 @@ PHONY += __modinst_pre
 __modinst_pre:
 	@rm -rf $(MODLIB)/kernel
 	@rm -f $(MODLIB)/source
-	@mkdir -p $(MODLIB)/kernel
+	@mkdir -p $(MODLIB)
+ifdef CONFIG_MODULES
 	@ln -s $(abspath $(srctree)) $(MODLIB)/source
 	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
 		rm -f $(MODLIB)/build ; \
 		ln -s $(CURDIR) $(MODLIB)/build ; \
 	fi
 	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
+endif
 	@cp -f modules.builtin $(MODLIB)/
 	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
 
-endif # CONFIG_MODULES
-
 ###
 # Cleaning is done on three levels.
 # make clean     Delete most generated files
@@ -1930,6 +1918,13 @@ help:
 	@echo  '  clean           - remove generated files in module directory only'
 	@echo  ''
 
+__external_modules_error:
+	@echo >&2 '***'
+	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
+	@echo >&2 '*** You cannot build or install external modules.'
+	@echo >&2 '***'
+	@false
+
 endif # KBUILD_EXTMOD
 
 # ---------------------------------------------------------------------------
@@ -1966,13 +1961,10 @@ else # CONFIG_MODULES
 # Modules not configured
 # ---------------------------------------------------------------------------
 
-modules modules_install:
-	@echo >&2 '***'
-	@echo >&2 '*** The present kernel configuration has modules disabled.'
-	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
-	@echo >&2 '*** to enable CONFIG_MODULES.'
-	@echo >&2 '***'
-	@exit 1
+PHONY += __external_modules_error
+
+modules modules_install: __external_modules_error
+	@:
 
 KBUILD_MODULES :=
 
@@ -2045,7 +2037,7 @@ clean: $(clean-dirs)
 		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
 		-o -name '*.dt.yaml' \
 		-o -name '*.dwo' -o -name '*.lst' \
-		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
+		-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]' \

arch/arc/include/asm/linkage.h

@@ -8,6 +8,10 @@
 
 #include <asm/dwarf.h>
 
+#define ASM_NL		 `	/* use '`' to mark new line in macro */
+#define __ALIGN		.align 4
+#define __ALIGN_STR	__stringify(__ALIGN)
+
 #ifdef __ASSEMBLY__
 
 .macro ST2 e, o, off
@@ -28,10 +32,6 @@
 #endif
 .endm
 
-#define ASM_NL		 `	/* use '`' to mark new line in macro */
-#define __ALIGN		.align 4
-#define __ALIGN_STR	__stringify(__ALIGN)
-
 /* annotation for data we want in DCCM - if enabled in .config */
 .macro ARCFP_DATA nm
 #ifdef CONFIG_ARC_HAS_DCCM

arch/ia64/include/asm/Kbuild

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 generated-y += syscall_table.h
 generic-y += agp.h
+generic-y += export.h
 generic-y += kvm_para.h
 generic-y += mcs_spinlock.h
 generic-y += vtime.h

arch/ia64/kernel/head.S

@@ -170,7 +170,7 @@ RestRR:											\
 	__PAGE_ALIGNED_DATA
 
 	.global empty_zero_page
-EXPORT_DATA_SYMBOL_GPL(empty_zero_page)
+EXPORT_SYMBOL_GPL(empty_zero_page)
 empty_zero_page:
 	.skip PAGE_SIZE
 

arch/ia64/kernel/ivt.S

@@ -87,7 +87,7 @@
 
 	.align 32768	// align on 32KB boundary
 	.global ia64_ivt
-	EXPORT_DATA_SYMBOL(ia64_ivt)
+	EXPORT_SYMBOL(ia64_ivt)
 ia64_ivt:
 /////////////////////////////////////////////////////////////////////////////////////////
 // 0x0000 Entry 0 (size 64 bundles) VHPT Translation (8,20,47)

arch/mips/Makefile

@@ -346,7 +346,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 KBUILD_LDFLAGS		+= -m $(ld-emul)
 
 ifdef CONFIG_MIPS
-CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
+CHECKFLAGS += $(shell $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
 	grep -E -vw '__GNUC_(MINOR_|PATCHLEVEL_)?_' | \
 	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
 endif

arch/powerpc/kernel/vdso/Makefile

@@ -54,7 +54,7 @@ KASAN_SANITIZE := n
 KCSAN_SANITIZE := n
 
 ccflags-y := -fno-common -fno-builtin
-ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack
+ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS)
 ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld)
 ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
 

arch/um/os-Linux/user_syms.c

@@ -37,13 +37,6 @@ EXPORT_SYMBOL(vsyscall_ehdr);
 EXPORT_SYMBOL(vsyscall_end);
 #endif
 
-/* Export symbols used by GCC for the stack protector. */
-extern void __stack_smash_handler(void *) __attribute__((weak));
-EXPORT_SYMBOL(__stack_smash_handler);
-
-extern long __guard __attribute__((weak));
-EXPORT_SYMBOL(__guard);
-
 #ifdef _FORTIFY_SOURCE
 extern int __sprintf_chk(char *str, int flag, size_t len, const char *format);
 EXPORT_SYMBOL(__sprintf_chk);