Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler

Author: torvalds

Documentation/kbuild/Kconfig.recursion-issue-02

@@ -42,7 +42,7 @@
 # "select FW_LOADER" [0], in the end the simple alternative solution to this
 # problem consisted on matching semantics with newly introduced features.
 #
-# [0] http://lkml.kernel.org/r/[email protected]
+# [0] https://lkml.kernel.org/r/[email protected]
 
 mainmenu "Simple example to demo cumulative kconfig recursive dependency implication"
 

Documentation/kbuild/kconfig-language.rst

@@ -540,8 +540,8 @@ followed by a test macro::
 If you need to expose a compiler capability to makefiles and/or C source files,
 `CC_HAS_` is the recommended prefix for the config option::
 
-  config CC_HAS_STACKPROTECTOR_NONE
-	def_bool $(cc-option,-fno-stack-protector)
+  config CC_HAS_ASM_GOTO
+	def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC))
 
 Build as module only
 ~~~~~~~~~~~~~~~~~~~~
@@ -688,10 +688,10 @@ and real world requirements were not well understood. As it stands though
 only reverse engineering techniques have been used to deduce semantics from
 variability modeling languages such as Kconfig [3]_.
 
-.. [0] http://www.eng.uwaterloo.ca/~shshe/kconfig_semantics.pdf
-.. [1] http://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
-.. [2] http://gsd.uwaterloo.ca/sites/default/files/ase241-berger_0.pdf
-.. [3] http://gsd.uwaterloo.ca/sites/default/files/icse2011.pdf
+.. [0] https://www.eng.uwaterloo.ca/~shshe/kconfig_semantics.pdf
+.. [1] https://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
+.. [2] https://gsd.uwaterloo.ca/sites/default/files/ase241-berger_0.pdf
+.. [3] https://gsd.uwaterloo.ca/sites/default/files/icse2011.pdf
 
 Full SAT solver for Kconfig
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -710,10 +710,10 @@ such efforts somehow on Kconfig. There is enough interest from mentors of
 existing projects to not only help advise how to integrate this work upstream
 but also help maintain it long term. Interested developers should visit:
 
-http://kernelnewbies.org/KernelProjects/kconfig-sat
+https://kernelnewbies.org/KernelProjects/kconfig-sat
 
-.. [4] http://www.cs.cornell.edu/~sabhar/chapters/SATSolvers-KR-Handbook.pdf
-.. [5] http://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
+.. [4] https://www.cs.cornell.edu/~sabhar/chapters/SATSolvers-KR-Handbook.pdf
+.. [5] https://gsd.uwaterloo.ca/sites/default/files/vm-2013-berger.pdf
 .. [6] https://cados.cs.fau.de
 .. [7] https://vamos.cs.fau.de
 .. [8] https://undertaker.cs.fau.de

Documentation/kbuild/llvm.rst

@@ -76,7 +76,7 @@ Getting Help
 Getting LLVM
 -------------
 
-- http://releases.llvm.org/download.html
+- https://releases.llvm.org/download.html
 - https://github.com/llvm/llvm-project
 - https://llvm.org/docs/GettingStarted.html
 - https://llvm.org/docs/CMake.html

Documentation/kbuild/makefiles.rst

@@ -368,13 +368,24 @@ more details, with real examples.
 
 		subdir-ccflags-y := -Werror
 
+    ccflags-remove-y, asflags-remove-y
+	These flags are used to remove particular flags for the compiler,
+	assembler invocations.
+
+	Example::
+
+		ccflags-remove-$(CONFIG_MCOUNT) += -pg
+
     CFLAGS_$@, AFLAGS_$@
 	CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
 	kbuild makefile.
 
 	$(CFLAGS_$@) specifies per-file options for $(CC).  The $@
 	part has a literal value which specifies the file that it is for.
 
+	CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
+	can re-add compiler flags that were removed by ccflags-remove-y.
+
 	Example::
 
 		# drivers/scsi/Makefile
@@ -387,6 +398,9 @@ more details, with real examples.
 	$(AFLAGS_$@) is a similar feature for source files in assembly
 	languages.
 
+	AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
+	can re-add assembler flags that were removed by asflags-remove-y.
+
 	Example::
 
 		# arch/arm/kernel/Makefile
@@ -735,6 +749,10 @@ Both possibilities are described in the following.
 		hostprogs     := lxdialog
 		always-y      := $(hostprogs)
 
+	Kbuild provides the following shorthand for this:
+
+		hostprogs-always-y := lxdialog
+
 	This will tell kbuild to build lxdialog even if not referenced in
 	any rule.
 
@@ -817,7 +835,32 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
 5.4 When userspace programs are actually built
 ----------------------------------------------
 
-	Same as "When host programs are actually built".
+	Kbuild builds userspace programs only when told to do so.
+	There are two ways to do this.
+
+	(1) Add it as the prerequisite of another file
+
+	Example::
+
+		#net/bpfilter/Makefile
+		userprogs := bpfilter_umh
+		$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+
+	$(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
+
+	(2) Use always-y
+
+	Example::
+
+		userprogs := binderfs_example
+		always-y := $(userprogs)
+
+	Kbuild provides the following shorthand for this:
+
+		userprogs-always-y := binderfs_example
+
+	This will tell Kbuild to build binderfs_example when it visits this
+	Makefile.
 
 6 Kbuild clean infrastructure
 =============================

Makefile

@@ -508,7 +508,6 @@ KBUILD_CFLAGS_MODULE  := -DMODULE
 KBUILD_LDFLAGS_MODULE :=
 export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
 KBUILD_LDFLAGS :=
-GCC_PLUGINS_CFLAGS :=
 CLANG_FLAGS :=
 
 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
@@ -747,9 +746,6 @@ endif
 KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
 KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
 
-include scripts/Makefile.kcov
-include scripts/Makefile.gcc-plugins
-
 ifdef CONFIG_READABLE_ASM
 # Disable optimizations that make assembler listings hard to read.
 # reorder blocks reorders the control in the function
@@ -764,7 +760,7 @@ ifneq ($(CONFIG_FRAME_WARN),0)
 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 endif
 
-stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
+stackp-flags-y                                    := -fno-stack-protector
 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 
@@ -959,10 +955,19 @@ ifdef CONFIG_RETPOLINE
 KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
 endif
 
-include scripts/Makefile.kasan
-include scripts/Makefile.extrawarn
-include scripts/Makefile.ubsan
-include scripts/Makefile.kcsan
+# include additional Makefiles when needed
+include-y			:= scripts/Makefile.extrawarn
+include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
+include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
+include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
+include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
+include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
+
+include $(addprefix $(srctree)/, $(include-y))
+
+# scripts/Makefile.gcc-plugins is intentionally included last.
+# Do not add $(call cc-option,...) below this line. When you build the kernel
+# from the clean source tree, the GCC plugins do not exist at this point.
 
 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 KBUILD_CPPFLAGS += $(KCPPFLAGS)
@@ -1120,7 +1125,6 @@ KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
 
 export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
-export LDFLAGS_vmlinux
 # used by scripts/Makefile.package
 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
 
@@ -1152,7 +1156,7 @@ ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
 
 # Final link of vmlinux with optional arch pass after final link
 cmd_link-vmlinux =                                                 \
-	$(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ;    \
+	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE

arch/Kconfig

@@ -481,9 +481,6 @@ config HAVE_STACKPROTECTOR
 	  An arch should select this symbol if:
 	  - it has implemented a stack canary (e.g. __stack_chk_guard)
 
-config CC_HAS_STACKPROTECTOR_NONE
-	def_bool $(cc-option,-fno-stack-protector)
-
 config STACKPROTECTOR
 	bool "Stack Protector buffer overflow detection"
 	depends on HAVE_STACKPROTECTOR

arch/arm/boot/compressed/Makefile

@@ -84,9 +84,8 @@ endif
 
 # -fstack-protector-strong triggers protection checks in this code,
 # but it is being used too early to link to meaningful stack_chk logic.
-nossp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
 $(foreach o, $(libfdt_objs) atags_to_fdt.o, \
-	$(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt $(nossp-flags-y)))
+	$(eval CFLAGS_$(o) := -I $(srctree)/scripts/dtc/libfdt -fno-stack-protector))
 
 # These were previously generated C files. When you are building the kernel
 # with O=, make sure to remove the stale files in the output tree. Otherwise,
@@ -103,13 +102,9 @@ clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S
 
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
 
-ifeq ($(CONFIG_FUNCTION_TRACER),y)
-ORIG_CFLAGS := $(KBUILD_CFLAGS)
-KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
-endif
-
 ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin \
 	     -I$(obj) $(DISABLE_ARM_SSP_PER_TASK_PLUGIN)
+ccflags-remove-$(CONFIG_FUNCTION_TRACER) += -pg
 asflags-y := -DZIMAGE
 
 # Supply kernel BSS size to the decompressor via a linker symbol.

arch/mips/vdso/Makefile

@@ -35,8 +35,7 @@ cflags-vdso := $(ccflags-vdso) \
 	-O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
 	-mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \
 	-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
-	$(call cc-option, -fno-asynchronous-unwind-tables) \
-	$(call cc-option, -fno-stack-protector)
+	$(call cc-option, -fno-asynchronous-unwind-tables)
 aflags-vdso := $(ccflags-vdso) \
 	-D__ASSEMBLY__ -Wa,-gdwarf-2
 

arch/powerpc/boot/Makefile

@@ -366,6 +366,8 @@ initrd-y := $(patsubst zImage%, zImage.initrd%, \
 		$(patsubst treeImage%, treeImage.initrd%, $(image-y)))))
 initrd-y := $(filter-out $(image-y), $(initrd-y))
 targets	+= $(image-y) $(initrd-y)
+targets += $(foreach x, dtbImage uImage cuImage simpleImage treeImage, \
+		$(patsubst $(x).%, dts/%.dtb, $(filter $(x).%, $(image-y))))
 
 $(addprefix $(obj)/, $(initrd-y)): $(obj)/ramdisk.image.gz
 

arch/powerpc/kernel/Makefile

@@ -16,7 +16,7 @@ CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
 CFLAGS_btext.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
 CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
 
-CFLAGS_prom_init.o += $(call cc-option, -fno-stack-protector)
+CFLAGS_prom_init.o += -fno-stack-protector
 CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING
 CFLAGS_prom_init.o += -ffreestanding