From: Al Viro Date: Fri, 15 Jan 2016 19:01:22 +0000 (-0500) Subject: [kbuild] handle exports in lib-y objects reliably X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=7f2084fa55e6cb61f61b4224d4a8bafaeee55f9f;p=openwrt%2Fstaging%2Fblogic.git [kbuild] handle exports in lib-y objects reliably Collect the symbols exported by anything that goes into lib.a and add an empty object (lib-exports.o) with explicit undefs for each of those to obj-y. That allows to relax the rules regarding the use of exports in lib-* objects - right now an object with export can be in lib-* only if we are guaranteed that there always will be users in built-in parts of the tree, otherwise it needs to be in obj-*. As the result, we have an unholy mix of lib- and obj- in lib/Makefile and (especially) in arch/*/lib/Makefile. Moreover, a change in generic part of the kernel can lead to mysteriously missing exports on some configs. With this change we don't have to worry about that anymore. One side effect is that built-in.o now pulls everything with exports from the corresponding lib.a (if such exists). That's exactly what we want for linking vmlinux and fortunately it's almost the only thing built-in.o is used in. arch/ia64/hp/sim/boot/bootloader is the only exception and it's easy to get rid of now - just turn everything in arch/ia64/lib into lib-* and don't bother with arch/ia64/lib/built-in.o anymore. [AV: stylistic fix from Michal folded in] Acked-by: Michal Marek Signed-off-by: Al Viro --- diff --git a/arch/ia64/hp/sim/boot/Makefile b/arch/ia64/hp/sim/boot/Makefile index 2e805e0cc560..df6e9968c845 100644 --- a/arch/ia64/hp/sim/boot/Makefile +++ b/arch/ia64/hp/sim/boot/Makefile @@ -33,5 +33,5 @@ $(obj)/vmlinux.bin: vmlinux FORCE LDFLAGS_bootloader = -static -T $(obj)/bootloader: $(src)/bootloader.lds $(obj)/bootloader.o $(obj)/boot_head.o $(obj)/fw-emu.o \ - lib/lib.a arch/ia64/lib/built-in.o arch/ia64/lib/lib.a FORCE + lib/lib.a arch/ia64/lib/lib.a FORCE $(call if_changed,ld) diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile index 98771e2a78af..1f3d3877618f 100644 --- a/arch/ia64/lib/Makefile +++ b/arch/ia64/lib/Makefile @@ -2,17 +2,15 @@ # Makefile for ia64-specific library routines.. # -obj-y := io.o - -lib-y := __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o \ +lib-y := io.o __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o \ __divdi3.o __udivdi3.o __moddi3.o __umoddi3.o \ checksum.o clear_page.o csum_partial_copy.o \ clear_user.o strncpy_from_user.o strlen_user.o strnlen_user.o \ flush.o ip_fast_csum.o do_csum.o \ memset.o strlen.o xor.o -obj-$(CONFIG_ITANIUM) += copy_page.o copy_user.o memcpy.o -obj-$(CONFIG_MCKINLEY) += copy_page_mck.o memcpy_mck.o +lib-$(CONFIG_ITANIUM) += copy_page.o copy_user.o memcpy.o +lib-$(CONFIG_MCKINLEY) += copy_page_mck.o memcpy_mck.o lib-$(CONFIG_PERFMON) += carta_random.o AFLAGS___divdi3.o = diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 11602e5efb3b..cd9bf22bb027 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -81,6 +81,7 @@ endif ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),) lib-target := $(obj)/lib.a +obj-y += $(obj)/lib-ksyms.o endif ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),) @@ -395,6 +396,25 @@ $(lib-target): $(lib-y) FORCE $(call if_changed,link_l_target) 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)/;s/ .*/)/;p}' >$(ksyms-lds);\ + rm -f $(dummy-object);\ + $(AR) rcs$(KBUILD_ARFLAGS) $(dummy-object);\ + $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\ + rm $(dummy-object) $(ksyms-lds) + +$(obj)/lib-ksyms.o: $(lib-target) FORCE + $(call if_changed,export_list) endif #