Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries

- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy

- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script

- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions

- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y

- Use sha1 build id for both BFD linker and LLD

- Improve deb-pkg for reproducible builds and rootless builds

- Remove stale, useless scripts/namespace.pl

- Turn -Wreturn-type warning into error

- Fix build error of deb-pkg when CONFIG_MODULES=n

- Replace 'hostname' command with more portable 'uname -n'

- Various Makefile cleanups

* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...

Documentation/process/submit-checklist.rst

···
 
 9) Check cleanly with sparse.
 
-10) Use ``make checkstack`` and ``make namespacecheck`` and fix any problems
-    that they find.
+10) Use ``make checkstack`` and fix any problems that it finds.
 
     .. note::
 

MAINTAINERS

···
 B:	https://github.com/ClangBuiltLinux/linux/issues
 C:	irc://chat.freenode.net/clangbuiltlinux
 F:	Documentation/kbuild/llvm.rst
+F:	scripts/clang-tools/
 K:	\b(?i:clang|llvm)\b
 
 CLEANCACHE API

Makefile

···
 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 		   -Werror=implicit-function-declaration -Werror=implicit-int \
-		   -Wno-format-security \
+		   -Werror=return-type -Wno-format-security \
 		   -std=gnu89
 KBUILD_CPPFLAGS := -D__KERNEL__
 KBUILD_AFLAGS_KERNEL :=
···
 KBUILD_AFLAGS_MODULE  := -DMODULE
 KBUILD_CFLAGS_MODULE  := -DMODULE
 KBUILD_LDFLAGS_MODULE :=
-export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
 KBUILD_LDFLAGS :=
 CLANG_FLAGS :=
 
···
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KCSAN
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
···
 # in addition to whatever we do anyway.
 # Just "make" or "make all" shall build modules as well
 
-ifneq ($(filter all modules nsdeps,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
   KBUILD_MODULES := 1
 endif
 
···
 # This exploits the 'multi-target pattern rule' trick.
 # The syncconfig should be executed only once to make all the targets.
 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
+quiet_cmd_syncconfig = SYNC    $@
+      cmd_syncconfig = $(MAKE) -f $(srctree)/Makefile syncconfig
+
 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
-	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
+	+$(call cmd,syncconfig)
 else # !may-sync-config
 # External modules and some install targets need include/generated/autoconf.h
 # and include/config/auto.conf but do not care if they are up-to-date.
···
 KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 endif
 
-DEBUG_CFLAGS	:= $(call cc-option, -fno-var-tracking-assignments)
+# Workaround for GCC versions < 5.0
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
+ifdef CONFIG_CC_IS_GCC
+DEBUG_CFLAGS	:= $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
+endif
 
 ifdef CONFIG_DEBUG_INFO
+
 ifdef CONFIG_DEBUG_INFO_SPLIT
 DEBUG_CFLAGS	+= -gsplit-dwarf
 else
 DEBUG_CFLAGS	+= -g
 endif
+
 KBUILD_AFLAGS	+= -Wa,-gdwarf-2
-endif
+
 ifdef CONFIG_DEBUG_INFO_DWARF4
 DEBUG_CFLAGS	+= -gdwarf-4
 endif
···
 KBUILD_AFLAGS	+= -gz=zlib
 KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
 endif
+
+endif # CONFIG_DEBUG_INFO
 
 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 export DEBUG_CFLAGS
···
 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 
 # disable invalid "can't wrap" optimizations for signed / pointers
-KBUILD_CFLAGS	+= $(call cc-option,-fno-strict-overflow)
+KBUILD_CFLAGS	+= -fno-strict-overflow
 
 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
-KBUILD_CFLAGS  += $(call cc-option,-fno-stack-check,)
+KBUILD_CFLAGS  += -fno-stack-check
 
 # conserve stack if available
 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 
 # Prohibit date/time macros, which would make the build non-deterministic
-KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
+KBUILD_CFLAGS   += -Werror=date-time
 
 # enforce correct pointer usage
 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
···
 KBUILD_AFLAGS   += $(KAFLAGS)
 KBUILD_CFLAGS   += $(KCFLAGS)
 
-KBUILD_LDFLAGS_MODULE += --build-id
-LDFLAGS_vmlinux += --build-id
+KBUILD_LDFLAGS_MODULE += --build-id=sha1
+LDFLAGS_vmlinux += --build-id=sha1
 
 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 LDFLAGS_vmlinux	+= $(call ld-option, -X,)
···
 # using awk while concatenating to the final file.
 
 PHONY += modules
-modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check
+modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 PHONY += modules_check
···
 # Target to prepare building external modules
 PHONY += modules_prepare
 modules_prepare: prepare
+	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
 
 # Target to install modules
 PHONY += modules_install
···
 
 # Directories & files removed with 'make clean'
 CLEAN_FILES += include/ksym vmlinux.symvers \
-	       modules.builtin modules.builtin.modinfo modules.nsdeps
+	       modules.builtin modules.builtin.modinfo modules.nsdeps \
+	       compile_commands.json
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \
···
 	 echo  ''
 	@echo  'Static analysers:'
 	@echo  '  checkstack      - Generate a list of stack hogs'
-	@echo  '  namespacecheck  - Name space analysis on compiled kernel'
 	@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  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
+	@echo  '  clang-analyzer  - Check with clang static analyzer'
+	@echo  '  clang-tidy      - Check with clang-tidy'
 	@echo  ''
 	@echo  'Tools:'
 	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
···
 #                      Install the modules built in the module directory
 #                      Assumes install directory is already created
 
-# We are always building modules
+# We are always building only modules.
+KBUILD_BUILTIN :=
 KBUILD_MODULES := 1
 
 build-dirs := $(KBUILD_EXTMOD)
 PHONY += modules
-modules: descend
+modules: $(MODORDER)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+
+$(MODORDER): descend
+	@:
 
 PHONY += modules_install
 modules_install: _emodinst_ _emodinst_post
···
 _emodinst_post: _emodinst_
 	$(call cmd,depmod)
 
+compile_commands.json: $(extmod-prefix)compile_commands.json
+PHONY += compile_commands.json
+
 clean-dirs := $(KBUILD_EXTMOD)
-clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps
+clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
+	$(KBUILD_EXTMOD)/compile_commands.json
 
 PHONY += help
 help:
···
 	@echo  '  clean           - remove generated files in module directory only'
 	@echo  ''
 
-PHONY += prepare
+# no-op for external module builds
+PHONY += prepare modules_prepare
+
 endif # KBUILD_EXTMOD
 
 # Single targets
···
 endif
 
 PHONY += single_modpost
-single_modpost: $(single-no-ko)
+single_modpost: $(single-no-ko) modules_prepare
 	$(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
···
 nsdeps: modules
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
 
+# Clang Tooling
+# ---------------------------------------------------------------------------
+
+quiet_cmd_gen_compile_commands = GEN     $@
+      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
+
+$(extmod-prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
+	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
+	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
+	$(call if_changed,gen_compile_commands)
+
+targets += $(extmod-prefix)compile_commands.json
+
+PHONY += clang-tidy clang-analyzer
+
+ifdef CONFIG_CC_IS_CLANG
+quiet_cmd_clang_tools = CHECK   $<
+      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
+
+clang-tidy clang-analyzer: $(extmod-prefix)compile_commands.json
+	$(call cmd,clang_tools)
+else
+clang-tidy clang-analyzer:
+	@echo "$@ requires CC=clang" >&2
+	@false
+endif
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
-PHONY += includecheck versioncheck coccicheck namespacecheck export_report
+PHONY += includecheck versioncheck coccicheck export_report
 
 includecheck:
 	find $(srctree)/* $(RCS_FIND_IGNORE) \
···
 
 coccicheck:
 	$(Q)$(BASH) $(srctree)/scripts/$@
-
-namespacecheck:
-	$(PERL) $(srctree)/scripts/namespace.pl
 
 export_report:
 	$(PERL) $(srctree)/scripts/export_report.pl

arch/arm/Makefile

···
 # linker. All sections should be explicitly named in the linker script.
 LDFLAGS_vmlinux += $(call ld-option, --orphan-handling=warn)
 
-ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
-KBUILD_LDS_MODULE	+= $(srctree)/arch/arm/kernel/module.lds
-endif
-
 GZFLAGS		:=-9
 #KBUILD_CFLAGS	+=-pipe
 

arch/arm/kernel/module.lds arch/arm/include/asm/module.lds.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifdef CONFIG_ARM_MODULE_PLTS
 SECTIONS {
 	.plt : { BYTE(0) }
 	.init.plt : { BYTE(0) }
 }
+#endif

arch/arm/vdso/Makefile

···
 ldflags-$(CONFIG_CPU_ENDIAN_BE8) := --be8
 ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
 	    -z max-page-size=4096 -nostdlib -shared $(ldflags-y) \
-	    --hash-style=sysv --build-id \
+	    --hash-style=sysv --build-id=sha1 \
 	    -T
 
 obj-$(CONFIG_VDSO) += vdso.o

arch/arm64/Makefile

···
 
 CHECKFLAGS	+= -D__aarch64__
 
-ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
-KBUILD_LDS_MODULE	+= $(srctree)/arch/arm64/kernel/module.lds
-endif
-
 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
   KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
   CC_FLAGS_FTRACE := -fpatchable-function-entry=2

arch/arm64/kernel/module.lds arch/arm64/include/asm/module.lds.h

···
+#ifdef CONFIG_ARM64_MODULE_PLTS
 SECTIONS {
 	.plt (NOLOAD) : { BYTE(0) }
 	.init.plt (NOLOAD) : { BYTE(0) }
 	.text.ftrace_trampoline (NOLOAD) : { BYTE(0) }
 }
+#endif

arch/arm64/kernel/vdso/Makefile

···
 # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
 # preparation in build-time C")).
 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv	\
-	     -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id -n	\
+	     -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id=sha1 -n	\
 	     $(btildflags-y) -T
 
 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
 ccflags-y += -DDISABLE_BRANCH_PROFILING
 
 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS)
-KBUILD_CFLAGS			+= $(DISABLE_LTO)
 KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
···
 GCOV_PROFILE := n
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency (incbin is bad)

arch/arm64/kernel/vdso32/Makefile

···
 # Some useful compiler-dependent flags from top-level Makefile
 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
-VDSO_CFLAGS += $(call cc32-option,-fno-strict-overflow)
+VDSO_CFLAGS += -fno-strict-overflow
 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
-VDSO_CFLAGS += $(call cc32-option,-Werror=date-time)
+VDSO_CFLAGS += -Werror=date-time
 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
 
 # The 32-bit compiler does not provide 128-bit integers, which are used in
···
 VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
 VDSO_LDFLAGS += -nostdlib -shared -mfloat-abi=soft
 VDSO_LDFLAGS += -Wl,--hash-style=sysv
-VDSO_LDFLAGS += -Wl,--build-id
+VDSO_LDFLAGS += -Wl,--build-id=sha1
 VDSO_LDFLAGS += $(call cc32-ldoption,-fuse-ld=bfd)
 
 
···
 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency (vdso.s includes vdso.so through incbin)

arch/ia64/Makefile

···
 
 OBJCOPYFLAGS	:= --strip-all
 LDFLAGS_vmlinux	:= -static
-KBUILD_LDS_MODULE += $(srctree)/arch/ia64/module.lds
 KBUILD_AFLAGS_KERNEL := -mconstant-gp
 EXTRA		:=
 

arch/m68k/Makefile

···
 endif
 
 KBUILD_LDFLAGS := -m m68kelf
-KBUILD_LDS_MODULE += $(srctree)/arch/m68k/kernel/module.lds
 
 ifdef CONFIG_SUN3
 LDFLAGS_vmlinux = -N

arch/mips/vdso/Makefile

···
 # VDSO linker flags.
 ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
 	$(filter -E%,$(KBUILD_CFLAGS)) -nostdlib -shared \
-	-G 0 --eh-frame-hdr --hash-style=sysv --build-id -T
+	-G 0 --eh-frame-hdr --hash-style=sysv --build-id=sha1 -T
 
 CFLAGS_REMOVE_vdso.o = -pg
 

arch/nds32/kernel/vdso/Makefile

···
 
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency

arch/powerpc/Makefile

···
 ifdef CONFIG_PPC32
 KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
 else
-KBUILD_LDS_MODULE += $(srctree)/arch/powerpc/kernel/module.lds
 ifeq ($(call ld-ifversion, -ge, 225000000, y),y)
 # Have the linker provide sfpr if possible.
 # There is a corresponding test in arch/powerpc/lib/Makefile

arch/powerpc/kernel/vdso32/Makefile

···
 asflags-y := -D__VDSO32__ -s
 
 obj-y += vdso32_wrapper.o
-extra-y += vdso32.lds
+targets += vdso32.lds
 CPPFLAGS_vdso32.lds += -P -C -Upowerpc
 
 # Force dependency (incbin is bad)

arch/powerpc/kernel/vdso64/Makefile

···
 asflags-y := -D__VDSO64__ -s
 
 obj-y += vdso64_wrapper.o
-extra-y += vdso64.lds
+targets += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 
 # Force dependency (incbin is bad)

arch/riscv/Makefile

···
 ifeq ($(CONFIG_CMODEL_MEDANY),y)
 	KBUILD_CFLAGS += -mcmodel=medany
 endif
-ifeq ($(CONFIG_MODULE_SECTIONS),y)
-	KBUILD_LDS_MODULE += $(srctree)/arch/riscv/kernel/module.lds
-endif
 ifeq ($(CONFIG_PERF_EVENTS),y)
         KBUILD_CFLAGS += -fno-omit-frame-pointer
 endif

arch/riscv/kernel/module.lds arch/riscv/include/asm/module.lds.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2017 Andes Technology Corporation */
-
+#ifdef CONFIG_MODULE_SECTIONS
 SECTIONS {
 	.plt (NOLOAD) : { BYTE(0) }
 	.got (NOLOAD) : { BYTE(0) }
 	.got.plt (NOLOAD) : { BYTE(0) }
 }
+#endif

arch/riscv/kernel/vdso/Makefile

···
 # refer to these symbols in the kernel code rather than hand-coded addresses.
 
 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-	-Wl,--build-id -Wl,--hash-style=both
+	-Wl,--build-id=sha1 -Wl,--hash-style=both
 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
 	$(call if_changed,vdsold)
 

arch/s390/kernel/vdso64/Makefile

···
 KBUILD_CFLAGS_64 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_64 += -m64 -fPIC -shared -fno-common -fno-builtin
 ldflags-y := -fPIC -shared -nostdlib -soname=linux-vdso64.so.1 \
-	     --hash-style=both --build-id -T
+	     --hash-style=both --build-id=sha1 -T
 
 $(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_64)
 $(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_64)
 
 obj-y += vdso64_wrapper.o
-extra-y += vdso64.lds
+targets += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 
 # Disable gcov profiling, ubsan and kasan for VDSO code

arch/sparc/vdso/Makefile

···
 # Building vDSO images for sparc.
 #
 
-KBUILD_CFLAGS += $(DISABLE_LTO)
-
 VDSO64-$(CONFIG_SPARC64)	:= y
 VDSOCOMPAT-$(CONFIG_COMPAT)	:= y
 
···
 		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
 		sh $(srctree)/$(src)/checkundef.sh '$(OBJDUMP)' '$@'
 
-VDSO_LDFLAGS = -shared --hash-style=both --build-id -Bsymbolic
+VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 -Bsymbolic
 GCOV_PROFILE := n
 
 #

arch/um/include/asm/Kbuild

···
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
 generic-y += mmiowb.h
+generic-y += module.lds.h
 generic-y += param.h
 generic-y += pci.h
 generic-y += percpu.h

arch/x86/entry/vdso/Makefile

···
 ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
 include $(srctree)/lib/vdso/Makefile
 
-KBUILD_CFLAGS += $(DISABLE_LTO)
-
 # Sanitizer runtimes are unavailable and cannot be linked here.
 KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
···
 		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
 		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 
-VDSO_LDFLAGS = -shared --hash-style=both --build-id \
+VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 	$(call ld-option, --eh-frame-hdr) -Bsymbolic
 GCOV_PROFILE := n
 

include/asm-generic/Kbuild

···
 mandatory-y += mmu.h
 mandatory-y += mmu_context.h
 mandatory-y += module.h
+mandatory-y += module.lds.h
 mandatory-y += msi.h
 mandatory-y += pci.h
 mandatory-y += percpu.h

include/asm-generic/module.lds.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_MODULE_LDS_H
+#define __ASM_GENERIC_MODULE_LDS_H
+
+/*
+ * <asm/module.lds.h> can specify arch-specific sections for linking modules.
+ * Empty for the asm-generic header.
+ */
+
+#endif /* __ASM_GENERIC_MODULE_LDS_H */

kernel/Makefile

···
 KCSAN_SANITIZE_kcov.o := n
 CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
 
-# cond_syscall is currently not LTO compatible
-CFLAGS_sys_ni.o = $(DISABLE_LTO)
-
 obj-y += sched/
 obj-y += locking/
 obj-y += power/

lib/Kconfig.debug

···
 
 	  If unsure, say N.
 
+if DEBUG_INFO
+
 config DEBUG_INFO_REDUCED
 	bool "Reduce debugging information"
-	depends on DEBUG_INFO
 	help
 	  If you say Y here gcc is instructed to generate less debugging
 	  information for structure types. This means that tools that
···
 
 config DEBUG_INFO_COMPRESSED
 	bool "Compressed debugging information"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gz=zlib)
 	depends on $(ld-option,--compress-debug-sections=zlib)
 	help
···
 
 config DEBUG_INFO_SPLIT
 	bool "Produce split debuginfo in .dwo files"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gsplit-dwarf)
 	help
 	  Generate debug info into separate .dwo files. This significantly
···
 
 config DEBUG_INFO_DWARF4
 	bool "Generate dwarf4 debuginfo"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gdwarf-4)
 	help
 	  Generate dwarf4 debug info. This requires recent versions
···
 
 config DEBUG_INFO_BTF
 	bool "Generate BTF typeinfo"
-	depends on DEBUG_INFO
 	depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
 	depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
 	help
···
 
 config GDB_SCRIPTS
 	bool "Provide GDB scripts for kernel debugging"
-	depends on DEBUG_INFO
 	help
 	  This creates the required links to GDB helper scripts in the
 	  build directory. If you load vmlinux into gdb, the helper
···
 	  additional functions are available to analyze a Linux kernel
 	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
 	  for further details.
+
+endif # DEBUG_INFO
 
 config ENABLE_MUST_CHECK
 	bool "Enable __must_check logic"

scripts/.gitignore

···
 extract-cert
 sign-file
 insert-sys-cert
+/module.lds

scripts/Kbuild.include

···
 # - If no file exist it is created
 # - If the content differ the new file is used
 # - If they are equal no change, and no timestamp update
-# - stdin is piped in from the first prerequisite ($<) so one has
-#   to specify a valid file as first prerequisite (often the kbuild file)
 define filechk
 	$(Q)set -e;						\
 	mkdir -p $(dir $@);					\

scripts/Makefile

···
 # The following programs are only built on demand
 hostprogs += unifdef
 
+# The module linker script is preprocessed on demand
+targets += module.lds
+
 subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
 subdir-$(CONFIG_MODVERSIONS) += genksyms
 subdir-$(CONFIG_SECURITY_SELINUX) += selinux

scripts/Makefile.build

···
 # ---------------------------------------------------------------------------
 
 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
-      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
+      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) -fverbose-asm -S -o $@ $<
 
 $(obj)/%.s: $(src)/%.c FORCE
 	$(call if_changed_dep,cc_s_c)

scripts/Makefile.kasan

···
 # SPDX-License-Identifier: GPL-2.0
-ifdef CONFIG_KASAN
 CFLAGS_KASAN_NOSANITIZE := -fno-builtin
 KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
-endif
 
 ifdef CONFIG_KASAN_GENERIC
 
···
 		$(instrumentation_flags)
 
 endif # CONFIG_KASAN_SW_TAGS
+
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE

scripts/Makefile.kcsan

···
 
 # Keep most options here optional, to allow enabling more compilers if absence
 # of some options does not break KCSAN nor causes false positive reports.
-CFLAGS_KCSAN := -fsanitize=thread \
+export CFLAGS_KCSAN := -fsanitize=thread \
 	$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls) \
 	$(call cc-option,$(call cc-param,tsan-compound-read-before-write=1),$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1))) \
 	$(call cc-param,tsan-distinguish-volatile=1)

scripts/Makefile.modfinal

···
       cmd_ld_ko_o =                                                     \
 	$(LD) -r $(KBUILD_LDFLAGS)					\
 		$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE)		\
-		$(addprefix -T , $(KBUILD_LDS_MODULE))			\
-		-o $@ $(filter %.o, $^);				\
+		-T scripts/module.lds -o $@ $(filter %.o, $^);		\
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
-$(modules): %.ko: %.o %.mod.o $(KBUILD_LDS_MODULE) FORCE
+$(modules): %.ko: %.o %.mod.o scripts/module.lds FORCE
 	+$(call if_changed,ld_ko_o)
 
 targets += $(modules) $(modules:.ko=.mod.o)

scripts/Makefile.ubsan

···
 # SPDX-License-Identifier: GPL-2.0
+
+export CFLAGS_UBSAN :=
+
 ifdef CONFIG_UBSAN_ALIGNMENT
       CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
 endif

scripts/clang-tools/gen_compile_commands.py

···
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2018
+#
+# Author: Tom Roeder <[e-mail]>
+#
+"""A tool for generating compile_commands.json in the Linux kernel."""
+
+import argparse
+import json
+import logging
+import os
+import re
+import subprocess
+
+_DEFAULT_OUTPUT = 'compile_commands.json'
+_DEFAULT_LOG_LEVEL = 'WARNING'
+
+_FILENAME_PATTERN = r'^\..*\.cmd$'
+_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
+_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
+
+
+def parse_arguments():
+    """Sets up and parses command-line arguments.
+
+    Returns:
+        log_level: A logging level to filter log output.
+        directory: The work directory where the objects were built.
+        ar: Command used for parsing .a archives.
+        output: Where to write the compile-commands JSON file.
+        paths: The list of files/directories to handle to find .cmd files.
+    """
+    usage = 'Creates a compile_commands.json database from kernel .cmd files'
+    parser = argparse.ArgumentParser(description=usage)
+
+    directory_help = ('specify the output directory used for the kernel build '
+                      '(defaults to the working directory)')
+    parser.add_argument('-d', '--directory', type=str, default='.',
+                        help=directory_help)
+
+    output_help = ('path to the output command database (defaults to ' +
+                   _DEFAULT_OUTPUT + ')')
+    parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
+                        help=output_help)
+
+    log_level_help = ('the level of log messages to produce (defaults to ' +
+                      _DEFAULT_LOG_LEVEL + ')')
+    parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
+                        default=_DEFAULT_LOG_LEVEL, help=log_level_help)
+
+    ar_help = 'command used for parsing .a archives'
+    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
+
+    paths_help = ('directories to search or files to parse '
+                  '(files should be *.o, *.a, or modules.order). '
+                  'If nothing is specified, the current directory is searched')
+    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
+
+    args = parser.parse_args()
+
+    return (args.log_level,
+            os.path.abspath(args.directory),
+            args.output,
+            args.ar,
+            args.paths if len(args.paths) > 0 else [args.directory])
+
+
+def cmdfiles_in_dir(directory):
+    """Generate the iterator of .cmd files found under the directory.
+
+    Walk under the given directory, and yield every .cmd file found.
+
+    Args:
+        directory: The directory to search for .cmd files.
+
+    Yields:
+        The path to a .cmd file.
+    """
+
+    filename_matcher = re.compile(_FILENAME_PATTERN)
+
+    for dirpath, _, filenames in os.walk(directory):
+        for filename in filenames:
+            if filename_matcher.match(filename):
+                yield os.path.join(dirpath, filename)
+
+
+def to_cmdfile(path):
+    """Return the path of .cmd file used for the given build artifact
+
+    Args:
+        Path: file path
+
+    Returns:
+        The path to .cmd file
+    """
+    dir, base = os.path.split(path)
+    return os.path.join(dir, '.' + base + '.cmd')
+
+
+def cmdfiles_for_o(obj):
+    """Generate the iterator of .cmd files associated with the object
+
+    Yield the .cmd file used to build the given object
+
+    Args:
+        obj: The object path
+
+    Yields:
+        The path to .cmd file
+    """
+    yield to_cmdfile(obj)
+
+
+def cmdfiles_for_a(archive, ar):
+    """Generate the iterator of .cmd files associated with the archive.
+
+    Parse the given archive, and yield every .cmd file used to build it.
+
+    Args:
+        archive: The archive to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
+        yield to_cmdfile(obj)
+
+
+def cmdfiles_for_modorder(modorder):
+    """Generate the iterator of .cmd files associated with the modules.order.
+
+    Parse the given modules.order, and yield every .cmd file used to build the
+    contained modules.
+
+    Args:
+        modorder: The modules.order file to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    with open(modorder) as f:
+        for line in f:
+            ko = line.rstrip()
+            base, ext = os.path.splitext(ko)
+            if ext != '.ko':
+                sys.exit('{}: module path must end with .ko'.format(ko))
+            mod = base + '.mod'
+	    # The first line of *.mod lists the objects that compose the module.
+            with open(mod) as m:
+                for obj in m.readline().split():
+                    yield to_cmdfile(obj)
+
+
+def process_line(root_directory, command_prefix, file_path):
+    """Extracts information from a .cmd line and creates an entry from it.
+
+    Args:
+        root_directory: The directory that was searched for .cmd files. Usually
+            used directly in the "directory" entry in compile_commands.json.
+        command_prefix: The extracted command line, up to the last element.
+        file_path: The .c file from the end of the extracted command.
+            Usually relative to root_directory, but sometimes absolute.
+
+    Returns:
+        An entry to append to compile_commands.
+
+    Raises:
+        ValueError: Could not find the extracted file based on file_path and
+            root_directory or file_directory.
+    """
+    # The .cmd files are intended to be included directly by Make, so they
+    # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
+    # kernel version). The compile_commands.json file is not interepreted
+    # by Make, so this code replaces the escaped version with '#'.
+    prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
+
+    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
+    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
+    if not os.path.exists(abs_path):
+        raise ValueError('File %s not found' % abs_path)
+    return {
+        'directory': root_directory,
+        'file': abs_path,
+        'command': prefix + file_path,
+    }
+
+
+def main():
+    """Walks through the directory and finds and parses .cmd files."""
+    log_level, directory, output, ar, paths = parse_arguments()
+
+    level = getattr(logging, log_level)
+    logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
+
+    line_matcher = re.compile(_LINE_PATTERN)
+
+    compile_commands = []
+
+    for path in paths:
+        # If 'path' is a directory, handle all .cmd files under it.
+        # Otherwise, handle .cmd files associated with the file.
+        # Most of built-in objects are linked via archives (built-in.a or lib.a)
+        # but some objects are linked to vmlinux directly.
+        # Modules are listed in modules.order.
+        if os.path.isdir(path):
+            cmdfiles = cmdfiles_in_dir(path)
+        elif path.endswith('.o'):
+            cmdfiles = cmdfiles_for_o(path)
+        elif path.endswith('.a'):
+            cmdfiles = cmdfiles_for_a(path, ar)
+        elif path.endswith('modules.order'):
+            cmdfiles = cmdfiles_for_modorder(path)
+        else:
+            sys.exit('{}: unknown file type'.format(path))
+
+        for cmdfile in cmdfiles:
+            with open(cmdfile, 'rt') as f:
+                result = line_matcher.match(f.readline())
+                if result:
+                    try:
+                        entry = process_line(directory, result.group(1),
+                                             result.group(2))
+                        compile_commands.append(entry)
+                    except ValueError as err:
+                        logging.info('Could not add line from %s: %s',
+                                     cmdfile, err)
+
+    with open(output, 'wt') as f:
+        json.dump(compile_commands, f, indent=2, sort_keys=True)
+
+
+if __name__ == '__main__':
+    main()

scripts/clang-tools/run-clang-tools.py

···
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2020
+#
+# Author: Nathan Huckleberry <[e-mail]>
+#
+"""A helper routine run clang-tidy and the clang static-analyzer on
+compile_commands.json.
+"""
+
+import argparse
+import json
+import multiprocessing
+import os
+import subprocess
+import sys
+
+
+def parse_arguments():
+    """Set up and parses command-line arguments.
+    Returns:
+        args: Dict of parsed args
+        Has keys: [path, type]
+    """
+    usage = """Run clang-tidy or the clang static-analyzer on a
+        compilation database."""
+    parser = argparse.ArgumentParser(description=usage)
+
+    type_help = "Type of analysis to be performed"
+    parser.add_argument("type",
+                        choices=["clang-tidy", "clang-analyzer"],
+                        help=type_help)
+    path_help = "Path to the compilation database to parse"
+    parser.add_argument("path", type=str, help=path_help)
+
+    return parser.parse_args()
+
+
+def init(l, a):
+    global lock
+    global args
+    lock = l
+    args = a
+
+
+def run_analysis(entry):
+    # Disable all checks, then re-enable the ones we want
+    checks = "-checks=-*,"
+    if args.type == "clang-tidy":
+        checks += "linuxkernel-*"
+    else:
+        checks += "clang-analyzer-*"
+    p = subprocess.run(["clang-tidy", "-p", args.path, checks, entry["file"]],
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.STDOUT,
+                       cwd=entry["directory"])
+    with lock:
+        sys.stderr.buffer.write(p.stdout)
+
+
+def main():
+    args = parse_arguments()
+
+    lock = multiprocessing.Lock()
+    pool = multiprocessing.Pool(initializer=init, initargs=(lock, args))
+    # Read JSON data into the datastore variable
+    with open(args.path, "r") as f:
+        datastore = json.load(f)
+        pool.map(run_analysis, datastore)
+
+
+if __name__ == "__main__":
+    main()

scripts/gen_compile_commands.py

···
-#!/usr/bin/env python
-# SPDX-License-Identifier: GPL-2.0
-#
-# Copyright (C) Google LLC, 2018
-#
-# Author: Tom Roeder <[e-mail]>
-#
-"""A tool for generating compile_commands.json in the Linux kernel."""
-
-import argparse
-import json
-import logging
-import os
-import re
-
-_DEFAULT_OUTPUT = 'compile_commands.json'
-_DEFAULT_LOG_LEVEL = 'WARNING'
-
-_FILENAME_PATTERN = r'^\..*\.cmd$'
-_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
-_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
-
-# A kernel build generally has over 2000 entries in its compile_commands.json
-# database. If this code finds 300 or fewer, then warn the user that they might
-# not have all the .cmd files, and they might need to compile the kernel.
-_LOW_COUNT_THRESHOLD = 300
-
-
-def parse_arguments():
-    """Sets up and parses command-line arguments.
-
-    Returns:
-        log_level: A logging level to filter log output.
-        directory: The directory to search for .cmd files.
-        output: Where to write the compile-commands JSON file.
-    """
-    usage = 'Creates a compile_commands.json database from kernel .cmd files'
-    parser = argparse.ArgumentParser(description=usage)
-
-    directory_help = ('Path to the kernel source directory to search '
-                      '(defaults to the working directory)')
-    parser.add_argument('-d', '--directory', type=str, help=directory_help)
-
-    output_help = ('The location to write compile_commands.json (defaults to '
-                   'compile_commands.json in the search directory)')
-    parser.add_argument('-o', '--output', type=str, help=output_help)
-
-    log_level_help = ('The level of log messages to produce (one of ' +
-                      ', '.join(_VALID_LOG_LEVELS) + '; defaults to ' +
-                      _DEFAULT_LOG_LEVEL + ')')
-    parser.add_argument(
-        '--log_level', type=str, default=_DEFAULT_LOG_LEVEL,
-        help=log_level_help)
-
-    args = parser.parse_args()
-
-    log_level = args.log_level
-    if log_level not in _VALID_LOG_LEVELS:
-        raise ValueError('%s is not a valid log level' % log_level)
-
-    directory = args.directory or os.getcwd()
-    output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)
-    directory = os.path.abspath(directory)
-
-    return log_level, directory, output
-
-
-def process_line(root_directory, file_directory, command_prefix, relative_path):
-    """Extracts information from a .cmd line and creates an entry from it.
-
-    Args:
-        root_directory: The directory that was searched for .cmd files. Usually
-            used directly in the "directory" entry in compile_commands.json.
-        file_directory: The path to the directory the .cmd file was found in.
-        command_prefix: The extracted command line, up to the last element.
-        relative_path: The .c file from the end of the extracted command.
-            Usually relative to root_directory, but sometimes relative to
-            file_directory and sometimes neither.
-
-    Returns:
-        An entry to append to compile_commands.
-
-    Raises:
-        ValueError: Could not find the extracted file based on relative_path and
-            root_directory or file_directory.
-    """
-    # The .cmd files are intended to be included directly by Make, so they
-    # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
-    # kernel version). The compile_commands.json file is not interepreted
-    # by Make, so this code replaces the escaped version with '#'.
-    prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
-
-    cur_dir = root_directory
-    expected_path = os.path.join(cur_dir, relative_path)
-    if not os.path.exists(expected_path):
-        # Try using file_directory instead. Some of the tools have a different
-        # style of .cmd file than the kernel.
-        cur_dir = file_directory
-        expected_path = os.path.join(cur_dir, relative_path)
-        if not os.path.exists(expected_path):
-            raise ValueError('File %s not in %s or %s' %
-                             (relative_path, root_directory, file_directory))
-    return {
-        'directory': cur_dir,
-        'file': relative_path,
-        'command': prefix + relative_path,
-    }
-
-
-def main():
-    """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output = parse_arguments()
-
-    level = getattr(logging, log_level)
-    logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
-
-    filename_matcher = re.compile(_FILENAME_PATTERN)
-    line_matcher = re.compile(_LINE_PATTERN)
-
-    compile_commands = []
-    for dirpath, _, filenames in os.walk(directory):
-        for filename in filenames:
-            if not filename_matcher.match(filename):
-                continue
-            filepath = os.path.join(dirpath, filename)
-
-            with open(filepath, 'rt') as f:
-                for line in f:
-                    result = line_matcher.match(line)
-                    if not result:
-                        continue
-
-                    try:
-                        entry = process_line(directory, dirpath,
-                                             result.group(1), result.group(2))
-                        compile_commands.append(entry)
-                    except ValueError as err:
-                        logging.info('Could not add line from %s: %s',
-                                     filepath, err)
-
-    with open(output, 'wt') as f:
-        json.dump(compile_commands, f, indent=2, sort_keys=True)
-
-    count = len(compile_commands)
-    if count < _LOW_COUNT_THRESHOLD:
-        logging.warning(
-            'Found %s entries. Have you compiled the kernel?', count)
-
-
-if __name__ == '__main__':
-    main()

scripts/kconfig/Makefile

···
 unexport CONFIG_
 
 xconfig: $(obj)/qconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 gconfig: $(obj)/gconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 menuconfig: $(obj)/mconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 config: $(obj)/conf
-	$< $(silent) --oldaskconfig $(Kconfig)
+	$(Q)$< $(silent) --oldaskconfig $(Kconfig)
 
 nconfig: $(obj)/nconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 build_menuconfig: $(obj)/mconf
 
···
 PHONY += $(simple-targets)
 
 $(simple-targets): $(obj)/conf
-	$< $(silent) --$@ $(Kconfig)
+	$(Q)$< $(silent) --$@ $(Kconfig)
 
 PHONY += savedefconfig defconfig
 
 savedefconfig: $(obj)/conf
-	$< $(silent) --$@=defconfig $(Kconfig)
+	$(Q)$< $(silent) --$@=defconfig $(Kconfig)
 
 defconfig: $(obj)/conf
 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)),)
···
 # CHECK: -o cache_dir=<path> working?
 PHONY += testconfig
 testconfig: $(obj)/conf
-	$(PYTHON3) -B -m pytest $(srctree)/$(src)/tests \
+	$(Q)$(PYTHON3) -B -m pytest $(srctree)/$(src)/tests \
 	-o cache_dir=$(abspath $(obj)/tests/.cache) \
 	$(if $(findstring 1,$(KBUILD_VERBOSE)),--capture=no)
 clean-files += tests/.cache

scripts/link-vmlinux.sh

···
 	printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
 }
 
-# Create ${2} .o file with all symbols from the ${1} object file
+# Create ${2} .S file with all symbols from the ${1} object file
 kallsyms()
 {
-	info KSYM ${2}
 	local kallsymopt;
 
 	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
···
 		kallsymopt="${kallsymopt} --base-relative"
 	fi
 
-	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
-		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
-
-	local afile="`basename ${2} .o`.S"
-
-	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
-	${CC} ${aflags} -c -o ${2} ${afile}
+	info KSYMS ${2}
+	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${2}
 }
 
 # Perform one step in kallsyms generation, including temporary linking of
···
 	kallsymso_prev=${kallsymso}
 	kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
 	kallsymso=${kallsyms_vmlinux}.o
+	kallsyms_S=${kallsyms_vmlinux}.S
 
 	vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
-	kallsyms ${kallsyms_vmlinux} ${kallsymso}
+	kallsyms ${kallsyms_vmlinux} ${kallsyms_S}
+
+	info AS ${kallsyms_S}
+	${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
+	      ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
+	      -c -o ${kallsymso} ${kallsyms_S}
 }
 
 # Create map file with all symbols from ${1}

scripts/mkcompile_h

···
 	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
 fi
 if test -z "$KBUILD_BUILD_HOST"; then
-	LINUX_COMPILE_HOST=`hostname`
+	LINUX_COMPILE_HOST=`uname -n`
 else
 	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
 fi

scripts/module-common.lds scripts/module.lds.S

···
 
 	__jump_table		0 : ALIGN(8) { KEEP(*(__jump_table)) }
 }
+
+/* bring in arch-specific sections */
+#include <asm/module.lds.h>

scripts/namespace.pl

···
-#!/usr/bin/env perl
-#
-#	namespace.pl.  Mon Aug 30 2004
-#
-#	Perform a name space analysis on the linux kernel.
-#
-#	Copyright Keith Owens <[e-mail]>.  GPL.
-#
-#	Invoke by changing directory to the top of the kernel object
-#	tree then namespace.pl, no parameters.
-#
-#	Tuned for 2.1.x kernels with the new module handling, it will
-#	work with 2.0 kernels as well.
-#
-#	Last change 2.6.9-rc1, adding support for separate source and object
-#	trees.
-#
-#	The source must be compiled/assembled first, the object files
-#	are the primary input to this script.  Incomplete or missing
-#	objects will result in a flawed analysis.  Compile both vmlinux
-#	and modules.
-#
-#	Even with complete objects, treat the result of the analysis
-#	with caution.  Some external references are only used by
-#	certain architectures, others with certain combinations of
-#	configuration parameters.  Ideally the source should include
-#	something like
-#
-#	#ifndef CONFIG_...
-#	static
-#	#endif
-#	symbol_definition;
-#
-#	so the symbols are defined as static unless a particular
-#	CONFIG_... requires it to be external.
-#
-#	A symbol that is suffixed with '(export only)' has these properties
-#
-#	* It is global.
-#	* It is marked EXPORT_SYMBOL or EXPORT_SYMBOL_GPL, either in the same
-#	  source file or a different source file.
-#	* Given the current .config, nothing uses the symbol.
-#
-#	The symbol is a candidate for conversion to static, plus removal of the
-#	export.  But be careful that a different .config might use the symbol.
-#
-#
-#	Name space analysis and cleanup is an iterative process.  You cannot
-#	expect to find all the problems in a single pass.
-#
-#	* Identify possibly unnecessary global declarations, verify that they
-#	  really are unnecessary and change them to static.
-#	* Compile and fix up gcc warnings about static, removing dead symbols
-#	  as necessary.
-#	* make clean and rebuild with different configs (especially
-#	  CONFIG_MODULES=n) to see which symbols are being defined when the
-#	  config does not require them.  These symbols bloat the kernel object
-#	  for no good reason, which is frustrating for embedded systems.
-#	* Wrap config sensitive symbols in #ifdef CONFIG_foo, as long as the
-#	  code does not get too ugly.
-#	* Repeat the name space analysis until you can live with with the
-#	  result.
-#
-
-use warnings;
-use strict;
-use File::Find;
-use File::Spec;
-
-my $nm = ($ENV{'NM'} || "nm") . " -p";
-my $objdump = ($ENV{'OBJDUMP'} || "objdump") . " -s -j .comment";
-my $srctree = File::Spec->curdir();
-my $objtree = File::Spec->curdir();
-$srctree = File::Spec->rel2abs($ENV{'srctree'}) if (exists($ENV{'srctree'}));
-$objtree = File::Spec->rel2abs($ENV{'objtree'}) if (exists($ENV{'objtree'}));
-
-if ($#ARGV != -1) {
-	print STDERR "usage: $0 takes no parameters\n";
-	die("giving up\n");
-}
-
-my %nmdata = ();	# nm data for each object
-my %def = ();		# all definitions for each name
-my %ksymtab = ();	# names that appear in __ksymtab_
-my %ref = ();		# $ref{$name} exists if there is a true external reference to $name
-my %export = ();	# $export{$name} exists if there is an EXPORT_... of $name
-
-my %nmexception = (
-    'fs/ext3/bitmap'			=> 1,
-    'fs/ext4/bitmap'			=> 1,
-    'arch/x86/lib/thunk_32'		=> 1,
-    'arch/x86/lib/cmpxchg'		=> 1,
-    'arch/x86/vdso/vdso32/note'		=> 1,
-    'lib/irq_regs'			=> 1,
-    'usr/initramfs_data'		=> 1,
-    'drivers/scsi/aic94xx/aic94xx_dump'	=> 1,
-    'drivers/scsi/libsas/sas_dump'	=> 1,
-    'lib/dec_and_lock'			=> 1,
-    'drivers/ide/ide-probe-mini'	=> 1,
-    'usr/initramfs_data'		=> 1,
-    'drivers/acpi/acpia/exdump'		=> 1,
-    'drivers/acpi/acpia/rsdump'		=> 1,
-    'drivers/acpi/acpia/nsdumpdv'	=> 1,
-    'drivers/acpi/acpia/nsdump'		=> 1,
-    'arch/ia64/sn/kernel/sn2/io'	=> 1,
-    'arch/ia64/kernel/gate-data'	=> 1,
-    'security/capability'		=> 1,
-    'fs/ntfs/sysctl'			=> 1,
-    'fs/jfs/jfs_debug'			=> 1,
-);
-
-my %nameexception = (
-    'mod_use_count_'	 => 1,
-    '__initramfs_end'	=> 1,
-    '__initramfs_start'	=> 1,
-    '_einittext'	=> 1,
-    '_sinittext'	=> 1,
-    'kallsyms_names'	=> 1,
-    'kallsyms_num_syms'	=> 1,
-    'kallsyms_addresses'=> 1,
-    'kallsyms_offsets'	=> 1,
-    'kallsyms_relative_base'=> 1,
-    '__this_module'	=> 1,
-    '_etext'		=> 1,
-    '_edata'		=> 1,
-    '_end'		=> 1,
-    '__bss_start'	=> 1,
-    '_text'		=> 1,
-    '_stext'		=> 1,
-    '__gp'		=> 1,
-    'ia64_unw_start'	=> 1,
-    'ia64_unw_end'	=> 1,
-    '__init_begin'	=> 1,
-    '__init_end'	=> 1,
-    '__bss_stop'	=> 1,
-    '__nosave_begin'	=> 1,
-    '__nosave_end'	=> 1,
-    'pg0'		=> 1,
-    'vdso_enabled'	=> 1,
-    '__stack_chk_fail'  => 1,
-    'VDSO32_PRELINK'	=> 1,
-    'VDSO32_vsyscall'	=> 1,
-    'VDSO32_rt_sigreturn'=>1,
-    'VDSO32_sigreturn'	=> 1,
-);
-
-
-&find(\&linux_objects, '.');	# find the objects and do_nm on them
-&list_multiply_defined();
-&resolve_external_references();
-&list_extra_externals();
-
-exit(0);
-
-sub linux_objects
-{
-	# Select objects, ignoring objects which are only created by
-	# merging other objects.  Also ignore all of modules, scripts
-	# and compressed.  Most conglomerate objects are handled by do_nm,
-	# this list only contains the special cases.  These include objects
-	# that are linked from just one other object and objects for which
-	# there is really no permanent source file.
-	my $basename = $_;
-	$_ = $File::Find::name;
-	s:^\./::;
-	if (/.*\.o$/ &&
-		! (
-		m:/built-in.a$:
-		|| m:arch/x86/vdso/:
-		|| m:arch/x86/boot/:
-		|| m:arch/ia64/ia32/ia32.o$:
-		|| m:arch/ia64/kernel/gate-syms.o$:
-		|| m:arch/ia64/lib/__divdi3.o$:
-		|| m:arch/ia64/lib/__divsi3.o$:
-		|| m:arch/ia64/lib/__moddi3.o$:
-		|| m:arch/ia64/lib/__modsi3.o$:
-		|| m:arch/ia64/lib/__udivdi3.o$:
-		|| m:arch/ia64/lib/__udivsi3.o$:
-		|| m:arch/ia64/lib/__umoddi3.o$:
-		|| m:arch/ia64/lib/__umodsi3.o$:
-		|| m:arch/ia64/scripts/check_gas_for_hint.o$:
-		|| m:arch/ia64/sn/kernel/xp.o$:
-		|| m:boot/bbootsect.o$:
-		|| m:boot/bsetup.o$:
-		|| m:/bootsect.o$:
-		|| m:/boot/setup.o$:
-		|| m:/compressed/:
-		|| m:drivers/cdrom/driver.o$:
-		|| m:drivers/char/drm/tdfx_drv.o$:
-		|| m:drivers/ide/ide-detect.o$:
-		|| m:drivers/ide/pci/idedriver-pci.o$:
-		|| m:drivers/media/media.o$:
-		|| m:drivers/scsi/sd_mod.o$:
-		|| m:drivers/video/video.o$:
-		|| m:fs/devpts/devpts.o$:
-		|| m:fs/exportfs/exportfs.o$:
-		|| m:fs/hugetlbfs/hugetlbfs.o$:
-		|| m:fs/msdos/msdos.o$:
-		|| m:fs/nls/nls.o$:
-		|| m:fs/ramfs/ramfs.o$:
-		|| m:fs/romfs/romfs.o$:
-		|| m:fs/vfat/vfat.o$:
-		|| m:init/mounts.o$:
-		|| m:^modules/:
-		|| m:net/netlink/netlink.o$:
-		|| m:net/sched/sched.o$:
-		|| m:/piggy.o$:
-		|| m:^scripts/:
-		|| m:sound/.*/snd-:
-		|| m:^.*/\.tmp_:
-		|| m:^\.tmp_:
-		|| m:/vmlinux-obj.o$:
-		|| m:^tools/:
-		)
-	) {
-		do_nm($basename, $_);
-	}
-	$_ = $basename;		# File::Find expects $_ untouched (undocumented)
-}
-
-sub do_nm
-{
-	my ($basename, $fullname) = @_;
-	my ($source, $type, $name);
-	if (! -e $basename) {
-		printf STDERR "$basename does not exist\n";
-		return;
-	}
-	if ($fullname !~ /\.o$/) {
-		printf STDERR "$fullname is not an object file\n";
-		return;
-	}
-	($source = $basename) =~ s/\.o$//;
-	if (-e "$source.c" || -e "$source.S") {
-		$source = File::Spec->catfile($objtree, $File::Find::dir, $source)
-	} else {
-		$source = File::Spec->catfile($srctree, $File::Find::dir, $source)
-	}
-	if (! -e "$source.c" && ! -e "$source.S") {
-		# No obvious source, exclude the object if it is conglomerate
-	        open(my $objdumpdata, "$objdump $basename|")
-		    or die "$objdump $fullname failed $!\n";
-
-		my $comment;
-		while (<$objdumpdata>) {
-			chomp();
-			if (/^In archive/) {
-				# Archives are always conglomerate
-				$comment = "GCC:GCC:";
-				last;
-			}
-			next if (! /^[ 0-9a-f]{5,} /);
-			$comment .= substr($_, 43);
-		}
-		close($objdumpdata);
-
-		if (!defined($comment) || $comment !~ /GCC\:.*GCC\:/m) {
-			printf STDERR "No source file found for $fullname\n";
-		}
-		return;
-	}
-	open (my $nmdata, "$nm $basename|")
-	    or die "$nm $fullname failed $!\n";
-
-	my @nmdata;
-	while (<$nmdata>) {
-		chop;
-		($type, $name) = (split(/ +/, $_, 3))[1..2];
-		# Expected types
-		# A absolute symbol
-		# B weak external reference to data that has been resolved
-		# C global variable, uninitialised
-		# D global variable, initialised
-		# G global variable, initialised, small data section
-		# R global array, initialised
-		# S global variable, uninitialised, small bss
-		# T global label/procedure
-		# U external reference
-		# W weak external reference to text that has been resolved
-		# V similar to W, but the value of the weak symbol becomes zero with no error.
-		# a assembler equate
-		# b static variable, uninitialised
-		# d static variable, initialised
-		# g static variable, initialised, small data section
-		# r static array, initialised
-		# s static variable, uninitialised, small bss
-		# t static label/procedures
-		# w weak external reference to text that has not been resolved
-		# v similar to w
-		# ? undefined type, used a lot by modules
-		if ($type !~ /^[ABCDGRSTUWVabdgrstwv?]$/) {
-			printf STDERR "nm output for $fullname contains unknown type '$_'\n";
-		}
-		elsif ($name =~ /\./) {
-			# name with '.' is local static
-		}
-		else {
-			$type = 'R' if ($type eq '?');	# binutils replaced ? with R at one point
-			# binutils keeps changing the type for exported symbols, force it to R
-			$type = 'R' if ($name =~ /^__ksymtab/ || $name =~ /^__kstrtab/);
-			$name =~ s/_R[a-f0-9]{8}$//;	# module versions adds this
-			if ($type =~ /[ABCDGRSTWV]/ &&
-				$name ne 'init_module' &&
-				$name ne 'cleanup_module' &&
-				$name ne 'Using_Versions' &&
-				$name !~ /^Version_[0-9]+$/ &&
-				$name !~ /^__parm_/ &&
-				$name !~ /^__kstrtab/ &&
-				$name !~ /^__ksymtab/ &&
-				$name !~ /^__kcrctab_/ &&
-				$name !~ /^__exitcall_/ &&
-				$name !~ /^__initcall_/ &&
-				$name !~ /^__kdb_initcall_/ &&
-				$name !~ /^__kdb_exitcall_/ &&
-				$name !~ /^__module_/ &&
-				$name !~ /^__mod_/ &&
-				$name !~ /^__crc_/ &&
-				$name ne '__this_module' &&
-				$name ne 'kernel_version') {
-				if (!exists($def{$name})) {
-					$def{$name} = [];
-				}
-				push(@{$def{$name}}, $fullname);
-			}
-			push(@nmdata, "$type $name");
-			if ($name =~ /^__ksymtab_/) {
-				$name = substr($name, 10);
-				if (!exists($ksymtab{$name})) {
-					$ksymtab{$name} = [];
-				}
-				push(@{$ksymtab{$name}}, $fullname);
-			}
-		}
-	}
-	close($nmdata);
-
-	if ($#nmdata < 0) {
-	    printf "No nm data for $fullname\n"
-		unless $nmexception{$fullname};
-	    return;
-	}
-	$nmdata{$fullname} = \@nmdata;
-}
-
-sub drop_def
-{
-	my ($object, $name) = @_;
-	my $nmdata = $nmdata{$object};
-	my ($i, $j);
-	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
-		if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
-			splice(@{$nmdata{$object}}, $i, 1);
-			my $def = $def{$name};
-			for ($j = 0; $j < $#{$def{$name}}; ++$j) {
-				if ($def{$name}[$j] eq $object) {
-					splice(@{$def{$name}}, $j, 1);
-				}
-			}
-			last;
-		}
-	}
-}
-
-sub list_multiply_defined
-{
-	foreach my $name (keys(%def)) {
-		if ($#{$def{$name}} > 0) {
-			# Special case for cond_syscall
-			if ($#{$def{$name}} == 1 &&
-			   ($name =~ /^sys_/ || $name =~ /^compat_sys_/ ||
-			    $name =~ /^sys32_/)) {
-				if($def{$name}[0] eq "kernel/sys_ni.o" ||
-				   $def{$name}[1] eq "kernel/sys_ni.o") {
-					&drop_def("kernel/sys_ni.o", $name);
-					next;
-				}
-			}
-
-			printf "$name is multiply defined in :-\n";
-			foreach my $module (@{$def{$name}}) {
-				printf "\t$module\n";
-			}
-		}
-	}
-}
-
-sub resolve_external_references
-{
-	my ($kstrtab, $ksymtab, $export);
-
-	printf "\n";
-	foreach my $object (keys(%nmdata)) {
-		my $nmdata = $nmdata{$object};
-		for (my $i = 0; $i <= $#{$nmdata}; ++$i) {
-			my ($type, $name) = split(' ', $nmdata->[$i], 2);
-			if ($type eq "U" || $type eq "w") {
-				if (exists($def{$name}) || exists($ksymtab{$name})) {
-					# add the owning object to the nmdata
-					$nmdata->[$i] = "$type $name $object";
-					# only count as a reference if it is not EXPORT_...
-					$kstrtab = "R __kstrtab_$name";
-					$ksymtab = "R __ksymtab_$name";
-					$export = 0;
-					for (my $j = 0; $j <= $#{$nmdata}; ++$j) {
-						if ($nmdata->[$j] eq $kstrtab ||
-						    $nmdata->[$j] eq $ksymtab) {
-							$export = 1;
-							last;
-						}
-					}
-					if ($export) {
-						$export{$name} = "";
-					}
-					else {
-						$ref{$name} = ""
-					}
-				}
-				elsif ( ! $nameexception{$name}
-					&& $name !~ /^__sched_text_/
-					&& $name !~ /^__start_/
-					&& $name !~ /^__end_/
-					&& $name !~ /^__stop_/
-					&& $name !~ /^__scheduling_functions_.*_here/
-					&& $name !~ /^__.*initcall_/
-					&& $name !~ /^__.*per_cpu_start/
-					&& $name !~ /^__.*per_cpu_end/
-					&& $name !~ /^__alt_instructions/
-					&& $name !~ /^__setup_/
-					&& $name !~ /^__mod_timer/
-					&& $name !~ /^__mod_page_state/
-					&& $name !~ /^init_module/
-					&& $name !~ /^cleanup_module/
-				) {
-					printf "Cannot resolve ";
-					printf "weak " if ($type eq "w");
-					printf "reference to $name from $object\n";
-				}
-			}
-		}
-	}
-}
-
-sub list_extra_externals
-{
-	my %noref = ();
-
-	foreach my $name (keys(%def)) {
-		if (! exists($ref{$name})) {
-			my @module = @{$def{$name}};
-			foreach my $module (@module) {
-				if (! exists($noref{$module})) {
-					$noref{$module} = [];
-				}
-				push(@{$noref{$module}}, $name);
-			}
-		}
-	}
-	if (%noref) {
-		printf "\nExternally defined symbols with no external references\n";
-		foreach my $module (sort(keys(%noref))) {
-			printf "  $module\n";
-			foreach (sort(@{$noref{$module}})) {
-			    my $export;
-			    if (exists($export{$_})) {
-				$export = " (export only)";
-			    } else {
-				$export = "";
-			    }
-			    printf "    $_$export\n";
-			}
-		}
-	}
-}

scripts/package/builddeb

···
 
 create_package() {
 	local pname="$1" pdir="$2"
+	local dpkg_deb_opts
 
 	mkdir -m 755 -p "$pdir/DEBIAN"
 	mkdir -p "$pdir/usr/share/doc/$pname"
 	cp debian/copyright "$pdir/usr/share/doc/$pname/"
 	cp debian/changelog "$pdir/usr/share/doc/$pname/changelog.Debian"
-	gzip -9 "$pdir/usr/share/doc/$pname/changelog.Debian"
+	gzip -n -9 "$pdir/usr/share/doc/$pname/changelog.Debian"
 	sh -c "cd '$pdir'; find . -type f ! -path './DEBIAN/*' -printf '%P\0' \
 		| xargs -r0 md5sum > DEBIAN/md5sums"
 
 	# Fix ownership and permissions
-	chown -R root:root "$pdir"
+	if [ "$DEB_RULES_REQUIRES_ROOT" = "no" ]; then
+		dpkg_deb_opts="--root-owner-group"
+	else
+		chown -R root:root "$pdir"
+	fi
 	chmod -R go-w "$pdir"
 	# in case we are in a restrictive umask environment like 0077
 	chmod -R a+rX "$pdir"
 
 	# Create the package
 	dpkg-gencontrol -p$pname -P"$pdir"
-	dpkg-deb ${KDEB_COMPRESS:+-Z$KDEB_COMPRESS} --build "$pdir" ..
+	dpkg-deb $dpkg_deb_opts ${KDEB_COMPRESS:+-Z$KDEB_COMPRESS} --build "$pdir" ..
 }
 
 deploy_kernel_headers () {
···
 		cd $srctree
 		find . arch/$SRCARCH -maxdepth 1 -name Makefile\*
 		find include scripts -type f -o -type l
-		find arch/$SRCARCH -name module.lds -o -name Kbuild.platforms -o -name Platform
+		find arch/$SRCARCH -name Kbuild.platforms -o -name Platform
 		find $(find arch/$SRCARCH -name include -o -name scripts -type d) -type f
 	) > debian/hdrsrcfiles
 
···
 done
 
 if [ "$ARCH" != "um" ]; then
-	deploy_kernel_headers debian/linux-headers
-	create_package linux-headers-$version debian/linux-headers
+	if is_enabled CONFIG_MODULES; then
+		deploy_kernel_headers debian/linux-headers
+		create_package linux-headers-$version debian/linux-headers
+	fi
 
 	deploy_libc_headers debian/linux-libc-dev
 	create_package linux-libc-dev debian/linux-libc-dev

scripts/package/mkdebian

···
 	packageversion=$version-$revision
 fi
 sourcename=$KDEB_SOURCENAME
-packagename=linux-image-$version
-kernel_headers_packagename=linux-headers-$version
-dbg_packagename=$packagename-dbg
-debarch=
-set_debarch
 
 if [ "$ARCH" = "um" ] ; then
-	packagename=user-mode-linux-$version
+	packagename=user-mode-linux
+else
+	packagename=linux-image
 fi
+
+debarch=
+set_debarch
 
 email=${DEBEMAIL-$EMAIL}
 
···
 Section: kernel
 Priority: optional
 Maintainer: $maintainer
+Rules-Requires-Root: no
 Build-Depends: bc, rsync, kmod, cpio, bison, flex | flex:native $extra_build_depends
 Homepage: https://www.kernel.org/
 
-Package: $packagename
+Package: $packagename-$version
 Architecture: $debarch
 Description: Linux kernel, version $version
  This package contains the Linux kernel, modules and corresponding other
  files, version: $version.
-
-Package: $kernel_headers_packagename
-Architecture: $debarch
-Description: Linux kernel headers for $version on $debarch
- This package provides kernel header files for $version on $debarch
- .
- This is useful for people who need to build external modules
 
 Package: linux-libc-dev
 Section: devel
···
 Multi-Arch: same
 EOF
 
+if is_enabled CONFIG_MODULES; then
+cat <<EOF >> debian/control
+
+Package: linux-headers-$version
+Architecture: $debarch
+Description: Linux kernel headers for $version on $debarch
+ This package provides kernel header files for $version on $debarch
+ .
+ This is useful for people who need to build external modules
+EOF
+fi
+
 if is_enabled CONFIG_DEBUG_INFO; then
 cat <<EOF >> debian/control
 
-Package: $dbg_packagename
+Package: linux-image-$version-dbg
 Section: debug
 Architecture: $debarch
 Description: Linux kernel debugging symbols for $version
···
 
 srctree ?= .
 
-build:
+build-indep:
+build-arch:
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
 	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile
 
-binary-arch:
+build: build-arch
+
+binary-indep:
+binary-arch: build-arch
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
 	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile intdeb-pkg
 

scripts/setlocalversion

···
 
 	# Check for git and a git repo.
 	if test -z "$(git rev-parse --show-cdup 2>/dev/null)" &&
-	   head=$(git rev-parse --verify --short HEAD 2>/dev/null); then
+	   head=$(git rev-parse --verify HEAD 2>/dev/null); then
 
 		# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
 		# it, because this version is defined in the top level Makefile.
···
 			fi
 			# If we are past a tagged commit (like
 			# "v2.6.30-rc5-302-g72357d5"), we pretty print it.
-			if atag="$(git describe 2>/dev/null)"; then
-				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'
+			#
+			# Ensure the abbreviated sha1 has exactly 12
+			# hex characters, to make the output
+			# independent of git version, local
+			# core.abbrev settings and/or total number of
+			# objects in the current repository - passing
+			# --abbrev=12 ensures a minimum of 12, and the
+			# awk substr() then picks the 'g' and first 12
+			# hex chars.
+			if atag="$(git describe --abbrev=12 2>/dev/null)"; then
+				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),substr($(NF),0,13))}'
 
-			# If we don't have a tag at all we print -g{commitish}.
+			# If we don't have a tag at all we print -g{commitish},
+			# again using exactly 12 hex chars.
 			else
+				head="$(echo $head | cut -c1-12)"
 				printf '%s%s' -g $head
 			fi
 		fi

tools/testing/selftests/bpf/Makefile

···
 
 $(OUTPUT)/urandom_read: urandom_read.c
 	$(call msg,BINARY,,$@)
-	$(Q)$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS) -Wl,--build-id
+	$(Q)$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS) -Wl,--build-id=sha1
 
 $(OUTPUT)/test_stub.o: test_stub.c $(BPFOBJ)
 	$(call msg,CC,,$@)