Merge tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support zstd-compressed debug info

 - Allow W=1 builds to detect objects shared among multiple modules

 - Add srcrpm-pkg target to generate a source RPM package

 - Make the -s option detection work for future GNU Make versions

 - Add -Werror to KBUILD_CPPFLAGS when CONFIG_WERROR=y

 - Allow W=1 builds to detect -Wundef warnings in any preprocessed files

 - Raise the minimum supported version of binutils to 2.25

 - Use $(intcmp ...) to compare integers if GNU Make >= 4.4 is used

 - Use $(file ...) to read a file if GNU Make >= 4.2 is used

 - Print error if GNU Make older than 3.82 is used

 - Allow modpost to detect section mismatches with Clang LTO

 - Include vmlinuz.efi into kernel tarballs for arm64 CONFIG_EFI_ZBOOT=y

* tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
  buildtar: fix tarballs with EFI_ZBOOT enabled
  modpost: Include '.text.*' in TEXT_SECTIONS
  padata: Mark padata_work_init() as __ref
  kbuild: ensure Make >= 3.82 is used
  kbuild: refactor the prerequisites of the modpost rule
  kbuild: change module.order to list *.o instead of *.ko
  kbuild: use .NOTINTERMEDIATE for future GNU Make versions
  kconfig: refactor Makefile to reduce process forks
  kbuild: add read-file macro
  kbuild: do not sort after reading modules.order
  kbuild: add test-{ge,gt,le,lt} macros
  Documentation: raise minimum supported version of binutils to 2.25
  kbuild: add -Wundef to KBUILD_CPPFLAGS for W=1 builds
  kbuild: move -Werror from KBUILD_CFLAGS to KBUILD_CPPFLAGS
  kbuild: Port silent mode detection to future gnu make.
  init/version.c: remove #include <generated/utsrelease.h>
  firmware_loader: remove #include <generated/utsrelease.h>
  modpost: Mark uuid_le type to be suitable only for MEI
  kbuild: add ability to make source rpm buildable using koji
  kbuild: warn objects shared among multiple modules
  ...

Author: torvalds

Documentation/process/changes.rst

@@ -35,7 +35,7 @@ Rust (optional)        1.62.0           rustc --version
 bindgen (optional)     0.56.0           bindgen --version
 GNU make               3.82             make --version
 bash                   4.2              bash --version
-binutils               2.23             ld -v
+binutils               2.25             ld -v
 flex                   2.5.35           flex --version
 bison                  2.0              bison --version
 pahole                 1.16             pahole --version
@@ -119,7 +119,7 @@ Bash 4.2 or newer is needed.
 Binutils
 --------
 
-Binutils 2.23 or newer is needed to build the kernel.
+Binutils 2.25 or newer is needed to build the kernel.
 
 pkg-config
 ----------

Makefile

@@ -11,6 +11,10 @@ NAME = Hurr durr I'ma ninja sloth
 # Comments in this file are targeted only to the developer, do not
 # expect to learn how to build the kernel reading this file.
 
+ifeq ($(filter undefine,$(.FEATURES)),)
+$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
+endif
+
 $(if $(filter __%, $(MAKECMDGOALS)), \
 	$(error targets prefixed with '__' are only for internal use))
 
@@ -93,10 +97,17 @@ endif
 
 # If the user is running make -s (silent mode), suppress echoing of
 # commands
+# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
 
-ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
-  quiet=silent_
-  KBUILD_VERBOSE = 0
+ifeq ($(filter 3.%,$(MAKE_VERSION)),)
+silence:=$(findstring s,$(firstword -$(MAKEFLAGS)))
+else
+silence:=$(findstring s,$(filter-out --%,$(MAKEFLAGS)))
+endif
+
+ifeq ($(silence),s)
+quiet=silent_
+KBUILD_VERBOSE = 0
 endif
 
 export quiet Q KBUILD_VERBOSE
@@ -369,7 +380,7 @@ else # !mixed-build
 include $(srctree)/scripts/Kbuild.include
 
 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
-KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
+KERNELRELEASE = $(call read-file, include/config/kernel.release)
 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 
@@ -859,7 +870,8 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 
 KBUILD_CFLAGS += $(stackp-flags-y)
 
-KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
+KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
+KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
 KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
 
 KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
@@ -990,7 +1002,7 @@ KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 # Check for frame size exceeding threshold during prolog/epilog insertion
 # when using lld < 13.0.0.
 ifneq ($(CONFIG_FRAME_WARN),0)
-ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
+ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
 KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 endif
 endif
@@ -1560,7 +1572,7 @@ __modinst_pre:
 		rm -f $(MODLIB)/build ; \
 		ln -s $(CURDIR) $(MODLIB)/build ; \
 	fi
-	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
+	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
 	@cp -f modules.builtin $(MODLIB)/
 	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
 

arch/riscv/Makefile

@@ -37,7 +37,7 @@ else
 endif
 
 ifeq ($(CONFIG_LD_IS_LLD),y)
-ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 150000; echo $$?),0)
+ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 150000),y)
 	KBUILD_CFLAGS += -mno-relax
 	KBUILD_AFLAGS += -mno-relax
 ifndef CONFIG_AS_IS_LLVM

arch/x86/Makefile

@@ -217,7 +217,7 @@ endif
 KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
 
 ifdef CONFIG_LTO_CLANG
-ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
+ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
 KBUILD_LDFLAGS	+= -plugin-opt=-stack-alignment=$(if $(CONFIG_X86_32),4,8)
 endif
 endif

drivers/base/firmware_loader/firmware.h

@@ -9,8 +9,6 @@
 #include <linux/list.h>
 #include <linux/completion.h>
 
-#include <generated/utsrelease.h>
-
 /**
  * enum fw_opt - options to control firmware loading behaviour
  *

init/version.c

@@ -15,7 +15,6 @@
 #include <linux/printk.h>
 #include <linux/uts.h>
 #include <linux/utsname.h>
-#include <generated/utsrelease.h>
 #include <linux/proc_ns.h>
 
 static int __init early_hostname(char *arg)

kernel/padata.c

@@ -83,8 +83,16 @@ static struct padata_work *padata_work_alloc(void)
 	return pw;
 }
 
-static void padata_work_init(struct padata_work *pw, work_func_t work_fn,
-			     void *data, int flags)
+/*
+ * This function is marked __ref because this function may be optimized in such
+ * a way that it directly refers to work_fn's address, which causes modpost to
+ * complain when work_fn is marked __init. This scenario was observed with clang
+ * LTO, where padata_work_init() was optimized to refer directly to
+ * padata_mt_helper() because the calls to padata_work_init() with other work_fn
+ * values were eliminated or inlined.
+ */
+static void __ref padata_work_init(struct padata_work *pw, work_func_t work_fn,
+				   void *data, int flags)
 {
 	if (flags & PADATA_WORK_ONSTACK)
 		INIT_WORK_ONSTACK(&pw->pw_work, work_fn);

lib/Kconfig.debug

@@ -312,8 +312,21 @@ config DEBUG_INFO_REDUCED
 	  DEBUG_INFO build and compile times are reduced too.
 	  Only works with newer gcc versions.
 
-config DEBUG_INFO_COMPRESSED
-	bool "Compressed debugging information"
+choice
+	prompt "Compressed Debug information"
+	help
+	  Compress the resulting debug info. Results in smaller debug info sections,
+	  but requires that consumers are able to decompress the results.
+
+	  If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
+
+config DEBUG_INFO_COMPRESSED_NONE
+	bool "Don't compress debug information"
+	help
+	  Don't compress debug info sections.
+
+config DEBUG_INFO_COMPRESSED_ZLIB
+	bool "Compress debugging information with zlib"
 	depends on $(cc-option,-gz=zlib)
 	depends on $(ld-option,--compress-debug-sections=zlib)
 	help
@@ -327,6 +340,18 @@ config DEBUG_INFO_COMPRESSED
 	  preferable to setting $KDEB_COMPRESS to "none" which would be even
 	  larger.
 
+config DEBUG_INFO_COMPRESSED_ZSTD
+	bool "Compress debugging information with zstd"
+	depends on $(cc-option,-gz=zstd)
+	depends on $(ld-option,--compress-debug-sections=zstd)
+	help
+	  Compress the debug information using zstd.  This may provide better
+	  compression than zlib, for about the same time costs, but requires newer
+	  toolchain support.  Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
+	  zstd.
+
+endchoice # "Compressed Debug information"
+
 config DEBUG_INFO_SPLIT
 	bool "Produce split debuginfo in .dwo files"
 	depends on $(cc-option,-gsplit-dwarf)

scripts/Kbuild.include

@@ -10,6 +10,26 @@ empty   :=
 space   := $(empty) $(empty)
 space_escape := _-_SPACE_-_
 pound := \#
+define newline
+
+
+endef
+
+###
+# Comparison macros.
+# Usage: $(call test-lt, $(CONFIG_LLD_VERSION), 150000)
+#
+# Use $(intcmp ...) if supported. (Make >= 4.4)
+# Otherwise, fall back to the 'test' shell command.
+ifeq ($(intcmp 1,0,,,y),y)
+test-ge = $(intcmp $(strip $1)0, $(strip $2)0,,y,y)
+test-gt = $(intcmp $(strip $1)0, $(strip $2)0,,,y)
+else
+test-ge = $(shell test $(strip $1)0 -ge $(strip $2)0 && echo y)
+test-gt = $(shell test $(strip $1)0 -gt $(strip $2)0 && echo y)
+endif
+test-le = $(call test-ge, $2, $1)
+test-lt = $(call test-gt, $2, $1)
 
 ###
 # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
@@ -40,6 +60,21 @@ escsq = $(subst $(squote),'\$(squote)',$1)
 # Quote a string to pass it to C files. foo => '"foo"'
 stringify = $(squote)$(quote)$1$(quote)$(squote)
 
+###
+# The path to Kbuild or Makefile. Kbuild has precedence over Makefile.
+kbuild-dir = $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
+kbuild-file = $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
+
+###
+# Read a file, replacing newlines with spaces
+#
+# Make 4.2 or later can read a file by using its builtin function.
+ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),)
+read-file = $(subst $(newline),$(space),$(file < $1))
+else
+read-file = $(shell cat $1 2>/dev/null)
+endif
+
 ###
 # Easy method for doing a status message
        kecho := :
@@ -150,9 +185,6 @@ endif
 make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))))
 
 # Find any prerequisites that are newer than target or that do not exist.
-# (This is not true for now; $? should contain any non-existent prerequisites,
-# but it does not work as expected when .SECONDARY is present. This seems a bug
-# of GNU Make.)
 # PHONY targets skipped in both cases.
 newer-prereqs = $(filter-out $(PHONY),$?)
 
@@ -228,4 +260,14 @@ endif
 .DELETE_ON_ERROR:
 
 # do not delete intermediate files automatically
+#
+# .NOTINTERMEDIATE is more correct, but only available on newer Make versions.
+# Make 4.4 introduced .NOTINTERMEDIATE, and it appears in .FEATURES, but the
+# global .NOTINTERMEDIATE does not work. We can use it on Make > 4.4.
+# Use .SECONDARY for older Make versions, but "newer-prereq" cannot detect
+# deleted files.
+ifneq ($(and $(filter notintermediate, $(.FEATURES)),$(filter-out 4.4,$(MAKE_VERSION))),)
+.NOTINTERMEDIATE:
+else
 .SECONDARY:
+endif

scripts/Makefile.asm-generic

@@ -10,15 +10,15 @@ PHONY := all
 all:
 
 src := $(subst /generated,,$(obj))
--include $(src)/Kbuild
+
+include $(srctree)/scripts/Kbuild.include
+-include $(kbuild-file)
 
 # $(generic)/Kbuild lists mandatory-y. Exclude um since it is a special case.
 ifneq ($(SRCARCH),um)
 include $(srctree)/$(generic)/Kbuild
 endif
 
-include $(srctree)/scripts/Kbuild.include
-
 redundant := $(filter $(mandatory-y) $(generated-y), $(generic-y))
 redundant += $(foreach f, $(generic-y), $(if $(wildcard $(srctree)/$(src)/$(f)),$(f)))
 redundant := $(sort $(redundant))