kbuild: Bump the build system to 5.1
Our last sync with the kernel was 5.1. Even that was a partial one
as some patches from 4.x kernels were already missing making the
transition to a modern kbuild infeasible.
We are so out of sync now, that tracking the patches and backporting
them one by one makes little sense and it's going to take ages.
This is an attempt to sync up Makefile[.lib/.kbuild].
Unfortunately due to sheer amount of patches this is not easy to review,
but that's what we decided during a community call.
One of the biggest changes is get rid of partial linking entirely and
build .a archives isntead of .o.
We diaviate from the kernel on that. Instead of calling a custom script
to create the archive symbol table, we call ar with rcTP (isntead of
rcSTP) since we want a resulting archive that's sauble with the linker.
The only affected platforms are PPC ones. Unfortunately I don't have any
of them around to test, but the objdump of the resulting files --
arch/powerpc/lib/built-in.[oa] looks identical.
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index aa48d24..998679f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -76,10 +76,12 @@
ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
lib-target := $(obj)/lib.a
+# Modified for U-Boot
+# real-obj-y += $(obj)/lib-ksyms.o
endif
-ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
-builtin-target := $(obj)/built-in.o
+ifneq ($(strip $(real-obj-y) $(need-builtin)),)
+builtin-target := $(obj)/built-in.a
endif
ifdef CONFIG_MODULES
@@ -102,7 +104,11 @@
cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
endif
-# Do section mismatch analysis for each module/built-in.o
+ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
+ cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
+endif
+
+# Do section mismatch analysis for each module/built-in.a
ifdef CONFIG_DEBUG_SECTION_MISMATCH
cmd_secanalysis = ; scripts/mod/modpost $@
endif
@@ -111,101 +117,94 @@
# ---------------------------------------------------------------------------
# Default is built-in, unless we know otherwise
+$(foreach x, i ll lst o s symtypes, $(patsubst %.o,%.$(x),$(real-obj-m))): \
+ part-of-module := y
+
modkern_cflags = \
$(if $(part-of-module), \
$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
quiet_modtag = $(if $(part-of-module),[M], )
-$(real-objs-m) : part-of-module := y
-$(real-objs-m:.o=.i) : part-of-module := y
-$(real-objs-m:.o=.s) : part-of-module := y
-$(real-objs-m:.o=.lst): part-of-module := y
-
-# Default for not multi-part modules
-modname = $(basetarget)
-
-$(multi-objs-m) : modname = $(modname-multi)
-$(multi-objs-m:.o=.i) : modname = $(modname-multi)
-$(multi-objs-m:.o=.s) : modname = $(modname-multi)
-$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
-$(multi-objs-y) : modname = $(modname-multi)
-$(multi-objs-y:.o=.i) : modname = $(modname-multi)
-$(multi-objs-y:.o=.s) : modname = $(modname-multi)
-$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
-
quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
-cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
+ cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
$(obj)/%.s: $(src)/%.c FORCE
$(call if_changed_dep,cc_s_c)
-quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
-cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
+quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
+cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
$(obj)/%.i: $(src)/%.c FORCE
- $(call if_changed_dep,cc_i_c)
+ $(call if_changed_dep,cpp_i_c)
-cmd_gensymtypes = \
+# These mirror gensymtypes_S and co below, keep them in synch.
+cmd_gensymtypes_c = \
$(CPP) -D__GENKSYMS__ $(c_flags) $< | \
- scripts/genksyms/genksyms $(if $(1), -T $(2)) \
+ scripts/genksyms/genksyms $(if $(1), -T $(2)) \
+ $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
$(if $(KBUILD_PRESERVE),-p) \
-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
cmd_cc_symtypes_c = \
- $(call cmd_gensymtypes,true,$@) >/dev/null; \
+ $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
test -s $@ || rm -f $@
$(obj)/%.symtypes : $(src)/%.c FORCE
$(call cmd,cc_symtypes_c)
+# LLVM assembly
+# Generate .ll files from .c
+quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
+ cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
+
+$(obj)/%.ll: $(src)/%.c FORCE
+ $(call if_changed_dep,cc_ll_c)
+
# C (.c) files
# The C file is compiled and updated dependency information is generated.
# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
+ cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
ifdef CONFIG_MODVERSIONS
# When module versioning is enabled the following steps are executed:
# o compile a <file>.o from <file>.c
# o if <file>.o doesn't contain a __ksymtab version, i.e. does
-# not export symbols, it's done
+# not export symbols, it's done.
# o otherwise, we calculate symbol versions using the good old
# genksyms on the preprocessed source and postprocess them in a way
# that they are usable as a linker script
# o generate .tmp_<file>.o from <file>.o using the linker to
# replace the unresolved symbols __crc_exported_symbol with
# the actual value of the checksum generated by genksyms
-
# o remove .tmp_<file>.o to <file>.o
-cmd_modversions = \
+
+cmd_modversions_c = \
if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
- $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
+ $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
> $(@D)/.tmp_$(@F:.o=.ver); \
\
- $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
+ $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
-T $(@D)/.tmp_$(@F:.o=.ver); \
mv -f $(@D)/.tmp_$(@F) $@; \
rm -f $(@D)/.tmp_$(@F:.o=.ver); \
- fi;
+ fi
endif
ifdef CONFIG_FTRACE_MCOUNT_RECORD
-# gcc 5 supports generating the mcount tables directly
-ifneq ($(call cc-option,-mrecord-mcount,y),y)
-KBUILD_CFLAGS += -mrecord-mcount
-else
-# else do it all manually
+ifndef CC_USING_RECORD_MCOUNT
+# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
ifdef BUILD_C_RECORDMCOUNT
ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
RECORDMCOUNT_FLAGS = -w
endif
# Due to recursion, we must skip empty.o.
# The empty.o file is created in the make process in order to determine
-# the target endianness and word size. It is made before all other C
-# files, including recordmcount.
+# the target endianness and word size. It is made before all other C
+# files, including recordmcount.
sub_cmd_record_mcount = \
if [ $(@) != "scripts/mod/empty.o" ]; then \
$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
@@ -213,17 +212,59 @@
recordmcount_source := $(srctree)/scripts/recordmcount.c \
$(srctree)/scripts/recordmcount.h
else
-sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
+sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
"$(if $(CONFIG_SYS_BIG_ENDIAN),big,little)" \
"$(if $(CONFIG_64BIT),64,32)" \
"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
"$(if $(part-of-module),1,0)" "$(@)";
recordmcount_source := $(srctree)/scripts/recordmcount.pl
+endif # BUILD_C_RECORDMCOUNT
+cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
+ $(sub_cmd_record_mcount))
+endif # CC_USING_RECORD_MCOUNT
+endif # CONFIG_FTRACE_MCOUNT_RECORD
+
+ifdef CONFIG_STACK_VALIDATION
+ifneq ($(SKIP_STACK_VALIDATION),1)
+
+__objtool_obj := $(objtree)/tools/objtool/objtool
+
+objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
+
+objtool_args += $(if $(part-of-module), --module,)
+
+ifndef CONFIG_FRAME_POINTER
+objtool_args += --no-fp
+endif
+ifdef CONFIG_GCOV_KERNEL
+objtool_args += --no-unreachable
endif
-cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
- $(sub_cmd_record_mcount))
-endif # -record-mcount
+ifdef CONFIG_RETPOLINE
+ objtool_args += --retpoline
+endif
+
+# '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
+cmd_objtool = $(if $(patsubst y%,, \
+ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
+ $(__objtool_obj) $(objtool_args) $@)
+objtool_obj = $(if $(patsubst y%,, \
+ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
+ $(__objtool_obj))
+
+endif # SKIP_STACK_VALIDATION
+endif # CONFIG_STACK_VALIDATION
+
+# Rebuild all objects when objtool changes, or is enabled/disabled.
+objtool_dep = $(objtool_obj) \
+ $(wildcard include/config/orc/unwinder.h \
+ include/config/stack/validation.h)
+
+ifdef CONFIG_TRIM_UNUSED_KSYMS
+cmd_gen_ksymdeps = \
+ $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
endif
define rule_cc_o_c
@@ -243,17 +284,25 @@
$(call cmd,modversions_S)
endef
+# List module undefined symbols (or empty line if not enabled)
+ifdef CONFIG_TRIM_UNUSED_KSYMS
+cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo
+else
+cmd_undef_syms = echo
+endif
+
# Built-in and composite module parts
-$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
# Single-part modules are special since we need to mark them in $(MODVERDIR)
-$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
- @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
+ @{ echo $(@:.o=.ko); echo $@; \
+ $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
quiet_cmd_cc_lst_c = MKLST $@
cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
@@ -268,29 +317,83 @@
modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
+$(real-obj-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
+$(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
+
+# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
+# or a file that it includes, in order to get versioned symbols. We build a
+# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
+# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
+#
+# This is convoluted. The .S file must first be preprocessed to run guards and
+# expand names, then the resulting exports must be constructed into plain
+# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
+# to make the genksyms input.
+#
+# These mirror gensymtypes_c and co above, keep them in synch.
+cmd_gensymtypes_S = \
+ { echo "\#include <linux/kernel.h>" ; \
+ echo "\#include <asm/asm-prototypes.h>" ; \
+ $(CPP) $(a_flags) $< | \
+ grep "\<___EXPORT_SYMBOL\>" | \
+ sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
+ $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
+ scripts/genksyms/genksyms $(if $(1), -T $(2)) \
+ $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
+ $(if $(KBUILD_PRESERVE),-p) \
+ -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
+
+quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
+cmd_cc_symtypes_S = \
+ $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
+ test -s $@ || rm -f $@
+
+$(obj)/%.symtypes : $(src)/%.S FORCE
+ $(call cmd,cc_symtypes_S)
+
-$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
-$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
-quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
-cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
+quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
+cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
$(obj)/%.s: $(src)/%.S FORCE
- $(call if_changed_dep,as_s_S)
+ $(call if_changed_dep,cpp_s_S)
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
-cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
+ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
+
+ifdef CONFIG_MODVERSIONS
+
+ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
+
+ifneq ($(ASM_PROTOTYPES),)
+
+# versioning matches the C process described above, with difference that
+# we parse asm-prototypes.h C header to get function definitions.
+
+cmd_modversions_S = \
+ if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
+ $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
+ > $(@D)/.tmp_$(@F:.o=.ver); \
+ \
+ $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
+ -T $(@D)/.tmp_$(@F:.o=.ver); \
+ mv -f $(@D)/.tmp_$(@F) $@; \
+ rm -f $(@D)/.tmp_$(@F:.o=.ver); \
+ fi
+endif
+endif
-$(obj)/%.o: $(src)/%.S FORCE
- $(call if_changed_dep,as_o_S)
+$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
+ $(call if_changed_rule,as_o_S)
-targets += $(real-objs-y) $(real-objs-m) $(lib-y)
+targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
targets += $(extra-y) $(MAKECMDGOALS) $(always)
targets += $(real-dtb-y) $(lib-y) $(always-y)
# Linker scripts preprocessor (.lds.S -> .lds)
# ---------------------------------------------------------------------------
quiet_cmd_cpp_lds_S = LDS $@
- cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
+ cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
-D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
$(obj)/%.lds: $(src)/%.lds.S FORCE
@@ -312,17 +415,17 @@
$(sort $(subdir-obj-y)): $(subdir-ym) ;
#
-# Rule to compile a set of .o files into one .o file
+# Rule to compile a set of .o files into one .a file (without symbol table)
#
ifdef builtin-target
-quiet_cmd_link_o_target = AR $@
-# If the list of objects to link is empty, just create an empty built-in.o
-cmd_link_o_target = $(if $(strip $(obj-y)),\
- rm -f $@; $(AR) cDPrsT $@ $(filter $(obj-y), $^), \
- rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@)
-$(builtin-target): $(obj-y) FORCE
- $(call if_changed,link_o_target)
+quiet_cmd_ar_builtin = AR $@
+# Modified for U-Boot, we create thin archives directly, instead of using the kernel script
+# Check f49821ee32b76 and 6358d6e8b98 in kernel
+ cmd_ar_builtin = rm -f $@; $(AR) rcTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)
+
+$(builtin-target): $(real-obj-y) FORCE
+ $(call if_changed,ar_builtin)
targets += $(builtin-target)
endif # builtin-target
@@ -341,7 +444,7 @@
$(Q)(cat /dev/null; $(modorder-cmds)) > $@
#
-# Rule to compile a set of .o files into one .a file
+# Rule to compile a set of .o files into one .a file (with symbol table)
#
ifdef lib-target
@@ -349,25 +452,40 @@
$(call if_changed,ar)
targets += $(lib-target)
-endif
-quiet_cmd_link_multi-y = AR $@
-cmd_link_multi-y = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(filter %.o,$^)
+dummy-object = $(obj)/.lib_exports.o
+ksyms-lds = $(dot-target).lds
-quiet_cmd_link_multi-m = AR [M] $@
-cmd_link_multi-m = $(cmd_link_multi-y)
+quiet_cmd_export_list = EXPORTS $@
+cmd_export_list = $(OBJDUMP) -h $< | \
+ 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);\
+ rm $(dummy-object) $(ksyms-lds)
-$(multi-used-y): FORCE
- $(call if_changed,link_multi-y)
-$(call multi_depend, $(multi-used-y), .o, -objs -y)
+$(obj)/lib-ksyms.o: $(lib-target) FORCE
+ $(call if_changed,export_list)
+
+targets += $(obj)/lib-ksyms.o
+
+endif
+
+# NOTE:
+# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
+# module is turned into a multi object module, $^ will contain header file
+# dependencies recorded in the .*.cmd file.
+quiet_cmd_link_multi-m = LD [M] $@
+cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)
$(multi-used-m): FORCE
$(call if_changed,link_multi-m)
- @{ echo $(@:.o=.ko); echo $(filter %.o,$^); } > $(MODVERDIR)/$(@F:.o=.mod)
-$(call multi_depend, $(multi-used-m), .o, -objs -y)
+ @{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
+ $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
+$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
-targets += $(multi-used-y) $(multi-used-m)
-
+targets += $(multi-used-m)
+targets := $(filter-out $(PHONY), $(targets))
# Add intermediate targets:
# When building objects with specific suffix patterns, add intermediate
@@ -375,9 +493,13 @@
intermediate_targets = $(foreach sfx, $(2), \
$(patsubst %$(strip $(1)),%$(sfx), \
$(filter %$(strip $(1)), $(targets))))
+# %.asn1.o <- %.asn1.[ch] <- %.asn1
+# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
# %.lex.o <- %.lex.c <- %.l
# %.tab.o <- %.tab.[ch] <- %.y
-targets += $(call intermediate_targets, .lex.o, .lex.c) \
+targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
+ $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
+ $(call intermediate_targets, .lex.o, .lex.c) \
$(call intermediate_targets, .tab.o, .tab.c .tab.h)
# Descending
@@ -385,7 +507,7 @@
PHONY += $(subdir-ym)
$(subdir-ym):
- $(Q)$(MAKE) $(build)=$@
+ $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------