linux_dsm_epyc7002/arch/arm/vdso/Makefile
Nathan Lynch f80f6531b4 ARM: 8344/1: VDSO: honor CONFIG_VDSO in Makefile
When CONFIG_VDSO=n, the build normally does not enter arch/arm/vdso/
because arch/arm/Makefile does not add it to core-y.

However, if the user runs 'make arch/arm/vdso/' the VDSO targets will
get visited.  This is because the VDSO Makefile itself does not
consider the value of CONFIG_VDSO.

It is arguably better and more consistent behavior to generate an
empty built-in.o when CONFIG_VDSO=n and the user attempts to build
arch/arm/vdso/.  It's nicer because it doesn't try to build things
that Kconfig dependencies are there to prevent (e.g. the dependency on
AEABI), and it's less confusing than building objects that won't be
used in the final image.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-21 15:28:02 +01:00

75 lines
2.2 KiB
Makefile

hostprogs-y := vdsomunge
obj-vdso := vgettimeofday.o datapage.o
# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
ccflags-y := -shared -fPIC -fno-common -fno-builtin -fno-stack-protector
ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 -DDISABLE_BRANCH_PROFILING
ccflags-y += -Wl,--no-undefined $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
obj-$(CONFIG_VDSO) += vdso.o
extra-$(CONFIG_VDSO) += vdso.lds
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
CFLAGS_REMOVE_vdso.o = -pg
# Force -O2 to avoid libgcc dependencies
CFLAGS_REMOVE_vgettimeofday.o = -pg -Os
CFLAGS_vgettimeofday.o = -O2
# Disable gcov profiling for VDSO code
GCOV_PROFILE := n
# Force dependency
$(obj)/vdso.o : $(obj)/vdso.so
# Link rule for the .so file
$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
$(call if_changed,vdsomunge)
# Strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
# Actual build commands
quiet_cmd_vdsold = VDSO $@
cmd_vdsold = $(CC) $(c_flags) -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) \
$(call cc-ldoption, -Wl$(comma)--build-id) \
-Wl,-Bsymbolic -Wl,-z,max-page-size=4096 \
-Wl,-z,common-page-size=4096 -o $@
quiet_cmd_vdsomunge = MUNGE $@
cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
#
# Install the unstripped copy of vdso.so.dbg. If our toolchain
# supports build-id, install .build-id links as well.
#
# Cribbed from arch/x86/vdso/Makefile.
#
quiet_cmd_vdso_install = INSTALL $<
define cmd_vdso_install
cp $< "$(MODLIB)/vdso/vdso.so"; \
if readelf -n $< | grep -q 'Build ID'; then \
buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
first=`echo $$buildid | cut -b-2`; \
last=`echo $$buildid | cut -b3-`; \
mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
ln -sf "../../vdso.so" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
fi
endef
$(MODLIB)/vdso: FORCE
@mkdir -p $(MODLIB)/vdso
PHONY += vdso_install
vdso_install: $(obj)/vdso.so.dbg $(MODLIB)/vdso FORCE
$(call cmd,vdso_install)