Merge tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - Fix build regressions for parisc, csky, nios2, openrisc

 - Simplify module builds for CONFIG_LTO_CLANG and CONFIG_X86_KERNEL_IBT

 - Remove arch/parisc/nm, which was presumably a workaround for old
   tools

 - Check the odd combination of EXPORT_SYMBOL and 'static' precisely

 - Make external module builds robust against "too long argument error"

 - Support j, k keys for moving the cursor in nconfig

* tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
  kbuild: Allow to select bash in a modified environment
  scripts: kconfig: nconf: make nconfig accept jk keybindings
  modpost: use fnmatch() to simplify match()
  modpost: simplify mod->name allocation
  kbuild: factor out the common objtool arguments
  kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o
  kbuild: clean .tmp_* pattern by make clean
  kbuild: remove redundant cleanups in scripts/link-vmlinux.sh
  kbuild: rebuild multi-object modules when objtool is updated
  kbuild: add cmd_and_savecmd macro
  kbuild: make *.mod rule robust against too long argument error
  kbuild: make built-in.a rule robust against too long argument error
  kbuild: check static EXPORT_SYMBOL* by script instead of modpost
  parisc: remove arch/parisc/nm
  kbuild: do not create *.prelink.o for Clang LTO or IBT
  kbuild: replace $(linked-object) with CONFIG options
  kbuild: do not try to parse *.cmd files for objects provided by compiler
  kbuild: replace $(if A,A,B) with $(or A,B) in scripts/Makefile.modpost
  modpost: squash if...else-if in find_elf_symbol2()
  modpost: reuse ARRAY_SIZE() macro for section_mismatch()
  ...

1 files changed, 38 insertions, 72 deletions

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 06400504150b..1f01ac65c0cd 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -88,10 +88,6 @@ endif
 targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
 				$(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
 
-ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
-targets-for-modules += $(patsubst %.o, %.prelink.o, $(filter %.o, $(obj-m)))
-endif
-
 ifdef need-modorder
 targets-for-modules += $(obj)/modules.order
 endif
@@ -152,8 +148,18 @@ $(obj)/%.ll: $(src)/%.c FORCE
 # The C file is compiled and updated dependency information is generated.
 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
 
+is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
+
+# When a module consists of a single object, there is no reason to keep LLVM IR.
+# Make $(LD) covert LLVM IR to ELF here.
+ifdef CONFIG_LTO_CLANG
+cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
+endif
+
 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
-      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool)
+      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
+		$(cmd_ld_single_m) \
+		$(cmd_objtool)
 
 ifdef CONFIG_MODVERSIONS
 # When module versioning is enabled the following steps are executed:
@@ -204,54 +210,25 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),
 	$(sub_cmd_record_mcount))
 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 
-ifdef CONFIG_OBJTOOL
-
-objtool := $(objtree)/tools/objtool/objtool
-
-objtool_args =								\
-	$(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label)	\
-	$(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr)		\
-	$(if $(CONFIG_X86_KERNEL_IBT), --ibt)				\
-	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
-	$(if $(CONFIG_UNWINDER_ORC), --orc)				\
-	$(if $(CONFIG_RETPOLINE), --retpoline)				\
-	$(if $(CONFIG_SLS), --sls)					\
-	$(if $(CONFIG_STACK_VALIDATION), --stackval)			\
-	$(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call)		\
-	--uaccess							\
-	$(if $(linked-object), --link)					\
-	$(if $(part-of-module), --module)				\
-	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
-
-cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
-cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
-
-endif # CONFIG_OBJTOOL
-
-ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
-
-# Skip objtool for LLVM bitcode
-$(obj)/%.o: objtool-enabled :=
-
-else
-
 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
 
-$(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
-	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
+is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 
-endif
+$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
 
 ifdef CONFIG_TRIM_UNUSED_KSYMS
 cmd_gen_ksymdeps = \
 	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
 endif
 
+cmd_check_local_export = $(srctree)/scripts/check-local-export $@
+
 define rule_cc_o_c
 	$(call cmd_and_fixdep,cc_o_c)
 	$(call cmd,gen_ksymdeps)
+	$(call cmd,check_local_export)
 	$(call cmd,checksrc)
 	$(call cmd,checkdoc)
 	$(call cmd,gen_objtooldep)
@@ -262,6 +239,7 @@ endef
 define rule_as_o_S
 	$(call cmd_and_fixdep,as_o_S)
 	$(call cmd,gen_ksymdeps)
+	$(call cmd,check_local_export)
 	$(call cmd,gen_objtooldep)
 	$(call cmd,gen_symversions_S)
 endef
@@ -271,27 +249,10 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 	$(call if_changed_rule,cc_o_c)
 	$(call cmd,force_checksrc)
 
-ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
-# Module .o files may contain LLVM bitcode, compile them into native code
-# before ELF processing
-quiet_cmd_cc_prelink_modules = LD [M]  $@
-      cmd_cc_prelink_modules =						\
-	$(LD) $(ld_flags) -r -o $@					\
-		--whole-archive $(filter-out FORCE,$^)			\
-		$(cmd_objtool)
-
-# objtool was skipped for LLVM bitcode, run it now that we have compiled
-# modules into native code
-$(obj)/%.prelink.o: objtool-enabled = y
-$(obj)/%.prelink.o: part-of-module := y
-$(obj)/%.prelink.o: linked-object := y
-
-$(obj)/%.prelink.o: $(obj)/%.o FORCE
-	$(call if_changed,cc_prelink_modules)
-endif
-
-cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \
-	$(AWK) -v RS='( |\n)' '!x[$$0]++' > $@
+# To make this rule robust against "Argument list too long" error,
+# ensure to add $(obj)/ prefix by a shell command.
+cmd_mod = echo $(call real-search, $*.o, .o, -objs -y -m) | \
+	$(AWK) -v RS='( |\n)' '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
 
 $(obj)/%.mod: FORCE
 	$(call if_changed,mod)
@@ -299,7 +260,7 @@ $(obj)/%.mod: FORCE
 # List module undefined symbols
 cmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@
 
-$(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE
+$(obj)/%.usyms: $(obj)/%.o FORCE
 	$(call if_changed,undefined_syms)
 
 quiet_cmd_cc_lst_c = MKLST   $@
@@ -392,9 +353,14 @@ $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
 #
+# To make this rule robust against "Argument list too long" error,
+# remove $(obj)/ prefix, and restore it by a shell command.
 
 quiet_cmd_ar_builtin = AR      $@
-      cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
+      cmd_ar_builtin = rm -f $@; \
+		echo $(patsubst $(obj)/%,%,$(real-prereqs)) | \
+		sed -E 's:([^ ]+):$(obj)/\1:g' | \
+		xargs $(AR) cDPrST $@
 
 $(obj)/built-in.a: $(real-obj-y) FORCE
 	$(call if_changed,ar_builtin)
@@ -421,18 +387,18 @@ $(obj)/modules.order: $(obj-m) FORCE
 $(obj)/lib.a: $(lib-y) FORCE
 	$(call if_changed,ar)
 
-ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
-quiet_cmd_link_multi-m = AR [M]  $@
-cmd_link_multi-m =						\
-	rm -f $@; 						\
-	$(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@)
-else
-quiet_cmd_link_multi-m = LD [M]  $@
-      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@)
-endif
+quiet_cmd_ld_multi_m = LD [M]  $@
+      cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
+
+define rule_ld_multi_m
+	$(call cmd_and_savecmd,ld_multi_m)
+	$(call cmd,gen_objtooldep)
+endef
 
+$(multi-obj-m): objtool-enabled := $(delay-objtool)
+$(multi-obj-m): part-of-module := y
 $(multi-obj-m): %.o: %.mod FORCE
-	$(call if_changed,link_multi-m)
+	$(call if_changed_rule,ld_multi_m)
 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 
 targets := $(filter-out $(PHONY), $(targets))