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ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO

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We use $(LD) to link vmlinux, modules, decompressors, etc.

VDSO is the only exceptional case where $(CC) is used as the linker
driver, but I do not know why we need to do so. VDSO uses a special
linker script, and does not link standard libraries at all.

I changed the Makefile to use $(LD) rather than $(CC). I confirmed
the same vdso.so.raw was still produced.

Users will be able to use their favorite linker (e.g. lld instead of
of bfd) by passing LD= from the command line.

My plan is to rewrite all VDSO Makefiles to use $(LD), then delete

cc-ldoption.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Masahiro Yamada 2019-04-18 10:57:49 +01:00 committed by Russell King
parent 32b25e9b98
commit fe00e50b2d
1 changed files with 8 additions and 13 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

21
arch/arm/vdso/Makefile
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@ -10,12 +10,12 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector ccflags-y := -fPIC -fno-common -fno-builtin -fno-stack-protector
ccflags-y += -DDISABLE_BRANCH_PROFILING ccflags-y += -DDISABLE_BRANCH_PROFILING
VDSO_LDFLAGS := -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 ldflags-y = -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 -z max-page-size=4096 -z common-page-size=4096 \
VDSO_LDFLAGS += -nostdlib -shared -nostdlib -shared \
VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) $(call ld-option, --hash-style=sysv) \
VDSO_LDFLAGS += $(call cc-ldoption, -Wl$(comma)--build-id) $(call ld-option, --build-id) \
VDSO_LDFLAGS += $(call cc-ldoption, -fuse-ld=bfd) -T
obj-$(CONFIG_VDSO) += vdso.o obj-$(CONFIG_VDSO) += vdso.o
extra-$(CONFIG_VDSO) += vdso.lds extra-$(CONFIG_VDSO) += vdso.lds
@ -37,8 +37,8 @@ KCOV_INSTRUMENT := n
$(obj)/vdso.o : $(obj)/vdso.so $(obj)/vdso.o : $(obj)/vdso.so
# Link rule for the .so file # Link rule for the .so file
$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE $(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold) $(call if_changed,ld)
$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
$(call if_changed,vdsomunge) $(call if_changed,vdsomunge)
@ -48,11 +48,6 @@ $(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE $(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy) $(call if_changed,objcopy)
# Actual build commands
quiet_cmd_vdsold = VDSO $@
cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \
-Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
quiet_cmd_vdsomunge = MUNGE $@ quiet_cmd_vdsomunge = MUNGE $@
cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@ cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@