Merge tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - improve fixdep to coalesce consecutive slashes in dep-files

 - fix some issues of the maintainer string generation in deb-pkg script

 - remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up
   several tools and linker scripts

 - clean-up modpost

 - allow to enable the dead code/data elimination for PowerPC in EXPERT
   mode

 - improve two coccinelle scripts for better performance

 - pass endianness and machine size flags to sparse for all architecture

 - misc fixes

* tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
  kbuild: add machine size to CHECKFLAGS
  kbuild: add endianness flag to CHEKCFLAGS
  kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice
  scripts: Fixed printf format mismatch
  scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation
  coccinelle: deref_null: improve performance
  coccinelle: mini_lock: improve performance
  powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
  kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled
  kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build
  kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION
  modpost: constify *modname function argument where possible
  modpost: remove redundant is_vmlinux() test
  modpost: use strstarts() helper more widely
  modpost: pass struct elf_info pointer to get_modinfo()
  checkpatch: remove VMLINUX_SYMBOL() check
  vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL()
  kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
  export.h: remove code for prefixing symbols with underscore
  depmod.sh: remove symbol prefix support
  ...

Makefile

@@ -802,13 +802,12 @@ KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 endif
 
 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
-KBUILD_CFLAGS	+= $(call cc-option,-ffunction-sections,)
-KBUILD_CFLAGS	+= $(call cc-option,-fdata-sections,)
+KBUILD_CFLAGS_KERNEL	+= $(call cc-option,-ffunction-sections,)
+KBUILD_CFLAGS_KERNEL	+= $(call cc-option,-fdata-sections,)
 endif
 
 # arch Makefile may override CC so keep this after arch Makefile is included
 NOSTDINC_FLAGS += -nostdinc -isystem $(call shell-cached,$(CC) -print-file-name=include)
-CHECKFLAGS     += $(NOSTDINC_FLAGS)
 
 # warn about C99 declaration after statement
 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
@@ -878,6 +877,12 @@ ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 LDFLAGS_vmlinux	+= $(call ld-option, -X,)
 endif
 
+# insure the checker run with the right endianness
+CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
+
+# the checker needs the correct machine size
+CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
+
 # Default kernel image to build when no specific target is given.
 # KBUILD_IMAGE may be overruled on the command line or
 # set in the environment
@@ -1763,7 +1768,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files))
 # Run depmod only if we have System.map and depmod is executable
 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
-                   $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
+                   $(KERNELRELEASE)
 
 # Create temporary dir for module support files
 # clean it up only when building all modules

arch/Kconfig

@@ -597,21 +597,6 @@ config CC_STACKPROTECTOR_AUTO
 
 endchoice
 
-config LD_DEAD_CODE_DATA_ELIMINATION
-	bool
-	help
-	  Select this if the architecture wants to do dead code and
-	  data elimination with the linker by compiling with
-	  -ffunction-sections -fdata-sections and linking with
-	  --gc-sections.
-
-	  This requires that the arch annotates or otherwise protects
-	  its external entry points from being discarded. Linker scripts
-	  must also merge .text.*, .data.*, and .bss.* correctly into
-	  output sections. Care must be taken not to pull in unrelated
-	  sections (e.g., '.text.init'). Typically '.' in section names
-	  is used to distinguish them from label names / C identifiers.
-
 config HAVE_ARCH_WITHIN_STACK_FRAMES
 	bool
 	help
@@ -687,12 +672,6 @@ config MODULES_USE_ELF_REL
 	  Modules only use ELF REL relocations.  Modules with ELF RELA
 	  relocations will give an error.
 
-config HAVE_UNDERSCORE_SYMBOL_PREFIX
-	bool
-	help
-	  Some architectures generate an _ in front of C symbols; things like
-	  module loading and assembly files need to know about this.
-
 config HAVE_IRQ_EXIT_ON_IRQ_STACK
 	bool
 	help

arch/alpha/Makefile

@@ -11,7 +11,7 @@
 NM := $(NM) -B
 
 LDFLAGS_vmlinux	:= -static -N #-relax
-CHECKFLAGS	+= -D__alpha__ -m64
+CHECKFLAGS	+= -D__alpha__
 cflags-y	:= -pipe -mno-fp-regs -ffixed-8
 cflags-y	+= $(call cc-option, -fno-jump-tables)
 

arch/arm/Makefile

@@ -135,7 +135,7 @@ endif
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
 KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
 
-CHECKFLAGS	+= -D__arm__ -m32
+CHECKFLAGS	+= -D__arm__
 
 #Default value
 head-y		:= arch/arm/kernel/head$(MMUEXT).o

arch/arm64/Makefile

@@ -78,7 +78,7 @@ LDFLAGS		+= -maarch64linux
 UTS_MACHINE	:= aarch64
 endif
 
-CHECKFLAGS	+= -D__aarch64__ -m64
+CHECKFLAGS	+= -D__aarch64__
 
 ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
 KBUILD_LDFLAGS_MODULE	+= -T $(srctree)/arch/arm64/kernel/module.lds

arch/ia64/Makefile

@@ -18,7 +18,7 @@ READELF := $(CROSS_COMPILE)readelf
 
 export AWK
 
-CHECKFLAGS	+= -m64 -D__ia64=1 -D__ia64__=1 -D_LP64 -D__LP64__
+CHECKFLAGS	+= -D__ia64=1 -D__ia64__=1 -D_LP64 -D__LP64__
 
 OBJCOPYFLAGS	:= --strip-all
 LDFLAGS_vmlinux	:= -static

arch/mips/Makefile

@@ -309,9 +309,6 @@ ifdef CONFIG_MIPS
 CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
 	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
 	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
-ifdef CONFIG_64BIT
-CHECKFLAGS		+= -m64
-endif
 endif
 
 OBJCOPYFLAGS		+= --remove-section=.reginfo

arch/openrisc/Makefile

@@ -25,7 +25,6 @@ LDFLAGS_vmlinux :=
 LIBGCC 		:= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 KBUILD_CFLAGS	+= -pipe -ffixed-r10 -D__linux__
-CHECKFLAGS	+= -mbig-endian
 
 ifeq ($(CONFIG_OPENRISC_HAVE_INST_MUL),y)
 	KBUILD_CFLAGS += $(call cc-option,-mhard-mul)

arch/parisc/Makefile

@@ -22,13 +22,13 @@ KBUILD_IMAGE := vmlinuz
 KBUILD_DEFCONFIG := default_defconfig
 
 NM		= sh $(srctree)/arch/parisc/nm
-CHECKFLAGS	+= -D__hppa__=1 -mbig-endian
+CHECKFLAGS	+= -D__hppa__=1
 LIBGCC		= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 export LIBGCC
 
 ifdef CONFIG_64BIT
 UTS_MACHINE	:= parisc64
-CHECKFLAGS	+= -D__LP64__=1 -m64
+CHECKFLAGS	+= -D__LP64__=1
 CC_ARCHES	= hppa64
 LD_BFD		:= elf64-hppa-linux
 else # 32-bit

arch/powerpc/Kconfig

@@ -198,6 +198,7 @@ config PPC
 	select HAVE_KPROBES
 	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_KRETPROBES
+	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
 	select HAVE_LIVEPATCH			if HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP

arch/powerpc/kernel/vmlinux.lds.S

@@ -89,7 +89,7 @@ SECTIONS
 	 */
 	.text BLOCK(0) : AT(ADDR(.text) - LOAD_OFFSET) {
 #ifdef CONFIG_LD_HEAD_STUB_CATCH
-		*(.linker_stub_catch);
+		KEEP(*(.linker_stub_catch));
 		. = . ;
 #endif
 
@@ -98,7 +98,7 @@ SECTIONS
 		ALIGN_FUNCTION();
 #endif
 		/* careful! __ftr_alt_* sections need to be close to .text */
-		*(.text.hot .text .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text);
+		*(.text.hot TEXT_MAIN .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text);
 		SCHED_TEXT
 		CPUIDLE_TEXT
 		LOCK_TEXT
@@ -184,10 +184,10 @@ SECTIONS
 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 		INIT_DATA
 		__vtop_table_begin = .;
-		*(.vtop_fixup);
+		KEEP(*(.vtop_fixup));
 		__vtop_table_end = .;
 		__ptov_table_begin = .;
-		*(.ptov_fixup);
+		KEEP(*(.ptov_fixup));
 		__ptov_table_end = .;
 	}
 
@@ -208,26 +208,26 @@ SECTIONS
 	. = ALIGN(8);
 	__ftr_fixup : AT(ADDR(__ftr_fixup) - LOAD_OFFSET) {
 		__start___ftr_fixup = .;
-		*(__ftr_fixup)
+		KEEP(*(__ftr_fixup))
 		__stop___ftr_fixup = .;
 	}
 	. = ALIGN(8);
 	__mmu_ftr_fixup : AT(ADDR(__mmu_ftr_fixup) - LOAD_OFFSET) {
 		__start___mmu_ftr_fixup = .;
-		*(__mmu_ftr_fixup)
+		KEEP(*(__mmu_ftr_fixup))
 		__stop___mmu_ftr_fixup = .;
 	}
 	. = ALIGN(8);
 	__lwsync_fixup : AT(ADDR(__lwsync_fixup) - LOAD_OFFSET) {
 		__start___lwsync_fixup = .;
-		*(__lwsync_fixup)
+		KEEP(*(__lwsync_fixup))
 		__stop___lwsync_fixup = .;
 	}
 #ifdef CONFIG_PPC64
 	. = ALIGN(8);
 	__fw_ftr_fixup : AT(ADDR(__fw_ftr_fixup) - LOAD_OFFSET) {
 		__start___fw_ftr_fixup = .;
-		*(__fw_ftr_fixup)
+		KEEP(*(__fw_ftr_fixup))
 		__stop___fw_ftr_fixup = .;
 	}
 #endif
@@ -240,7 +240,7 @@ SECTIONS
 	. = ALIGN(8);
 	.machine.desc : AT(ADDR(.machine.desc) - LOAD_OFFSET) {
 		__machine_desc_start = . ;
-		*(.machine.desc)
+		KEEP(*(.machine.desc))
 		__machine_desc_end = . ;
 	}
 #ifdef CONFIG_RELOCATABLE
@@ -288,7 +288,7 @@ SECTIONS
 	.data : AT(ADDR(.data) - LOAD_OFFSET) {
 		DATA_DATA
 		*(.data.rel*)
-		*(.sdata)
+		*(SDATA_MAIN)
 		*(.sdata2)
 		*(.got.plt) *(.got)
 		*(.plt)
@@ -303,7 +303,7 @@ SECTIONS
 
 	.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
 		__start_opd = .;
-		*(.opd)
+		KEEP(*(.opd))
 		__end_opd = .;
 	}
 

arch/s390/Makefile

@@ -18,7 +18,7 @@ KBUILD_CFLAGS	+= -m64
 KBUILD_AFLAGS	+= -m64
 UTS_MACHINE	:= s390x
 STACK_SIZE	:= 16384
-CHECKFLAGS	+= -D__s390__ -D__s390x__ -mbig-endian
+CHECKFLAGS	+= -D__s390__ -D__s390x__
 
 export LD_BFD
 

arch/sparc/Makefile

@@ -39,7 +39,7 @@ else
 # sparc64
 #
 
-CHECKFLAGS    += -D__sparc__ -D__sparc_v9__ -D__arch64__ -m64
+CHECKFLAGS    += -D__sparc__ -D__sparc_v9__ -D__arch64__
 LDFLAGS       := -m elf64_sparc
 export BITS   := 64
 UTS_MACHINE   := sparc64

arch/x86/Makefile

@@ -94,7 +94,7 @@ ifeq ($(CONFIG_X86_32),y)
 else
         BITS := 64
         UTS_MACHINE := x86_64
-        CHECKFLAGS += -D__x86_64__ -m64
+        CHECKFLAGS += -D__x86_64__
 
         biarch := -m64
         KBUILD_AFLAGS += -m64

include/asm-generic/export.h

@@ -19,42 +19,32 @@
 #define KCRC_ALIGN 4
 #endif
 
-#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
-#define KSYM(name) _##name
-#else
-#define KSYM(name) name
-#endif
-
 /*
  * note on .section use: @progbits vs %progbits nastiness doesn't matter,
  * since we immediately emit into those sections anyway.
  */
 .macro ___EXPORT_SYMBOL name,val,sec
 #ifdef CONFIG_MODULES
-	.globl KSYM(__ksymtab_\name)
+	.globl __ksymtab_\name
 	.section ___ksymtab\sec+\name,"a"
 	.balign KSYM_ALIGN
-KSYM(__ksymtab_\name):
-	__put \val, KSYM(__kstrtab_\name)
+__ksymtab_\name:
+	__put \val, __kstrtab_\name
 	.previous
 	.section __ksymtab_strings,"a"
-KSYM(__kstrtab_\name):
-#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
-	.asciz "_\name"
-#else
+__kstrtab_\name:
 	.asciz "\name"
-#endif
 	.previous
 #ifdef CONFIG_MODVERSIONS
 	.section ___kcrctab\sec+\name,"a"
 	.balign KCRC_ALIGN
-KSYM(__kcrctab_\name):
+__kcrctab_\name:
 #if defined(CONFIG_MODULE_REL_CRCS)
-	.long KSYM(__crc_\name) - .
+	.long __crc_\name - .
 #else
-	.long KSYM(__crc_\name)
+	.long __crc_\name
 #endif
-	.weak KSYM(__crc_\name)
+	.weak __crc_\name
 	.previous
 #endif
 #endif
@@ -84,12 +74,12 @@ KSYM(__kcrctab_\name):
 #endif
 
 #define EXPORT_SYMBOL(name)					\
-	__EXPORT_SYMBOL(name, KSYM_FUNC(KSYM(name)),)
+	__EXPORT_SYMBOL(name, KSYM_FUNC(name),)
 #define EXPORT_SYMBOL_GPL(name) 				\
-	__EXPORT_SYMBOL(name, KSYM_FUNC(KSYM(name)), _gpl)
+	__EXPORT_SYMBOL(name, KSYM_FUNC(name), _gpl)
 #define EXPORT_DATA_SYMBOL(name)				\
-	__EXPORT_SYMBOL(name, KSYM(name),)
+	__EXPORT_SYMBOL(name, name,)
 #define EXPORT_DATA_SYMBOL_GPL(name)				\
-	__EXPORT_SYMBOL(name, KSYM(name),_gpl)
+	__EXPORT_SYMBOL(name, name,_gpl)
 
 #endif

include/linux/export.h

@@ -10,14 +10,8 @@
  * hackers place grumpy comments in header files.
  */
 
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
-#define __VMLINUX_SYMBOL(x) _##x
-#define __VMLINUX_SYMBOL_STR(x) "_" #x
-#else
 #define __VMLINUX_SYMBOL(x) x
 #define __VMLINUX_SYMBOL_STR(x) #x
-#endif
 
 /* Indirect, so macros are expanded before pasting. */
 #define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
@@ -46,14 +40,14 @@ extern struct module __this_module;
 #if defined(CONFIG_MODULE_REL_CRCS)
 #define __CRC_SYMBOL(sym, sec)						\
 	asm("	.section \"___kcrctab" sec "+" #sym "\", \"a\"	\n"	\
-	    "	.weak	" VMLINUX_SYMBOL_STR(__crc_##sym) "	\n"	\
-	    "	.long	" VMLINUX_SYMBOL_STR(__crc_##sym) " - .	\n"	\
+	    "	.weak	__crc_" #sym "				\n"	\
+	    "	.long	__crc_" #sym " - .			\n"	\
 	    "	.previous					\n");
 #else
 #define __CRC_SYMBOL(sym, sec)						\
 	asm("	.section \"___kcrctab" sec "+" #sym "\", \"a\"	\n"	\
-	    "	.weak	" VMLINUX_SYMBOL_STR(__crc_##sym) "	\n"	\
-	    "	.long	" VMLINUX_SYMBOL_STR(__crc_##sym) "	\n"	\
+	    "	.weak	__crc_" #sym "				\n"	\
+	    "	.long	__crc_" #sym "				\n"	\
 	    "	.previous					\n");
 #endif
 #else
@@ -66,7 +60,7 @@ extern struct module __this_module;
 	__CRC_SYMBOL(sym, sec)						\
 	static const char __kstrtab_##sym[]				\
 	__attribute__((section("__ksymtab_strings"), aligned(1)))	\
-	= VMLINUX_SYMBOL_STR(sym);					\
+	= #sym;								\
 	static const struct kernel_symbol __ksymtab_##sym		\
 	__used								\
 	__attribute__((section("___ksymtab" sec "+" #sym), used))	\

init/Kconfig

@@ -1038,6 +1038,33 @@ config CC_OPTIMIZE_FOR_SIZE
 
 endchoice
 
+config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	bool
+	help
+	  This requires that the arch annotates or otherwise protects
+	  its external entry points from being discarded. Linker scripts
+	  must also merge .text.*, .data.*, and .bss.* correctly into
+	  output sections. Care must be taken not to pull in unrelated
+	  sections (e.g., '.text.init'). Typically '.' in section names
+	  is used to distinguish them from label names / C identifiers.
+
+config LD_DEAD_CODE_DATA_ELIMINATION
+	bool "Dead code and data elimination (EXPERIMENTAL)"
+	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	depends on EXPERT
+	help
+	  Select this if the architecture wants to do dead code and
+	  data elimination with the linker by compiling with
+	  -ffunction-sections -fdata-sections, and linking with
+	  --gc-sections.
+
+	  This can reduce on disk and in-memory size of the kernel
+	  code and static data, particularly for small configs and
+	  on small systems. This has the possibility of introducing
+	  silently broken kernel if the required annotations are not
+	  present. This option is not well tested yet, so use at your
+	  own risk.
+
 config SYSCTL
 	bool
 

scripts/Makefile.build

@@ -147,7 +147,6 @@ $(obj)/%.i: $(src)/%.c FORCE
 cmd_gensymtypes_c =                                                         \
     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
     $(GENKSYMS) $(if $(1), -T $(2))                                         \
-     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
      $(if $(KBUILD_PRESERVE),-p)                                            \
      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
@@ -355,7 +354,6 @@ cmd_gensymtypes_S =                                                         \
      sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
     $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \
     $(GENKSYMS) $(if $(1), -T $(2))                                         \
-     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
      $(if $(KBUILD_PRESERVE),-p)                                            \
      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
@@ -487,15 +485,10 @@ targets += $(lib-target)
 
 dummy-object = $(obj)/.lib_exports.o
 ksyms-lds = $(dot-target).lds
-ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
-ref_prefix = EXTERN(_
-else
-ref_prefix = EXTERN(
-endif
 
 quiet_cmd_export_list = EXPORTS $@
 cmd_export_list = $(OBJDUMP) -h $< | \
-	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
+	sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' >$(ksyms-lds);\
 	rm -f $(dummy-object);\
 	echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
 	$(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\

scripts/adjust_autoksyms.sh

@@ -61,9 +61,6 @@ for mod in "$MODVERDIR"/*.mod; do
 	sed -n -e '3{s/ /\n/g;/^$/!p;}' "$mod"
 done | sort -u |
 while read sym; do
-	if [ -n "$CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX" ]; then
-		sym="${sym#_}"
-	fi
 	echo "#define __KSYM_${sym} 1"
 done >> "$new_ksyms_file"