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Commit 4efca4ed authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michal Marek
Browse files

kbuild: modversions for EXPORT_SYMBOL() for asm 



Allow architectures to create asm/asm-prototypes.h file that
provides C prototypes for exported asm functions, which enables
proper CRC versions to be generated for them.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichal Marek <mmarek@suse.com>
parent 989cea5c

scripts/Makefile.build

+72 −6
Original line number Diff line number Diff line
@@ -159,7 +159,8 @@ cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $< 
$(obj)/%.i: $(src)/%.c FORCE

	$(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) $< |                                   \

    $(GENKSYMS) $(if $(1), -T $(2))                                         \

     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \
@@ -169,7 +170,7 @@ cmd_gensymtypes = \ 
quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@

cmd_cc_symtypes_c =                                                         \

    set -e;                                                                 \

    $(call cmd_gensymtypes,true,$@) >/dev/null;                             \

    $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \

    test -s $@ || rm -f $@



$(obj)/%.symtypes : $(src)/%.c FORCE
@@ -198,9 +199,10 @@ else 
#   the actual value of the checksum generated by genksyms



cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<

cmd_modversions =								\



cmd_modversions_c =								\

	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | 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) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\
@@ -268,13 +270,14 @@ endif # CONFIG_STACK_VALIDATION 
define rule_cc_o_c

	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \

	$(call cmd_and_fixdep,cc_o_c)					  \

	$(cmd_modversions)						  \

	$(cmd_modversions_c)						  \

	$(cmd_objtool)						          \

	$(call echo-cmd,record_mcount) $(cmd_record_mcount)

endef



define rule_as_o_S

	$(call cmd_and_fixdep,as_o_S)					  \

	$(cmd_modversions_S)						  \

	$(cmd_objtool)

endef
@@ -314,6 +317,39 @@ modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 
$(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)

$(real-objs-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 \([a-zA-Z0-9_]*\),.*/EXPORT_SYMBOL(\1);/' ) |  \

    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - |                                \

    $(GENKSYMS) $(if $(1), -T $(2))                                         \

     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \

     $(if $(KBUILD_PRESERVE),-p)                                            \

     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))



quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@

cmd_cc_symtypes_S =                                                         \

    set -e;                                                                 \

    $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \

    test -s $@ || rm -f $@



$(obj)/%.symtypes : $(src)/%.S FORCE

	$(call cmd,cc_symtypes_S)





quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@

cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $<
@@ -321,8 +357,38 @@ $(obj)/%.s: $(src)/%.S FORCE 
	$(call if_changed_dep,cpp_s_S)



quiet_cmd_as_o_S = AS $(quiet_modtag)  $@



ifndef CONFIG_MODVERSIONS

cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<



else



ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)



ifeq ($(ASM_PROTOTYPES),)

cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<



else



# versioning matches the C process described above, with difference that

# we parse asm-prototypes.h C header to get function definitions.



cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<



cmd_modversions_S =								\

	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\

		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\

		    > $(@D)/.tmp_$(@F:.o=.ver);					\

										\

		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\

			-T $(@D)/.tmp_$(@F:.o=.ver);				\

		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\

	else									\

		mv -f $(@D)/.tmp_$(@F) $@;					\

	fi;

endif

endif



$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE

	$(call if_changed_rule,as_o_S)