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arm64: 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 tested this,
and VDSO worked for me.

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>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Masahiro Yamada 2019-04-11 18:30:15 +09:00 committed by Will Deacon
parent d263119387
commit 691efbedc6
1 changed files with 3 additions and 10 deletions
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13
arch/arm64/kernel/vdso/Makefile
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@ -12,17 +12,12 @@ obj-vdso := gettimeofday.o note.o sigreturn.o
targets := $(obj-vdso) vdso.so vdso.so.dbg
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
ccflags-y := -shared -fno-common -fno-builtin
ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \
$(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 \
$(call ld-option, --hash-style=sysv) -n -T
# Disable gcov profiling for VDSO code
GCOV_PROFILE := n
# Workaround for bare-metal (ELF) toolchains that neglect to pass -shared
# down to collect2, resulting in silent corruption of the vDSO image.
ccflags-y += -Wl,-shared
obj-y += vdso.o
extra-y += vdso.lds
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
@ -32,7 +27,7 @@ $(obj)/vdso.o : $(obj)/vdso.so
# Link rule for the .so file, .lds has to be first
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
$(call if_changed,ld)
# Strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
@ -52,8 +47,6 @@ $(obj-vdso): %.o: %.S FORCE
$(call if_changed_dep,vdsoas)
# Actual build commands
quiet_cmd_vdsold = VDSOL $@
cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $(real-prereqs) -o $@
quiet_cmd_vdsoas = VDSOA $@
cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $<