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# SPDX-License-Identifier: GPL-2.0-only
# Copied from arch/tile/kernel/vdso/Makefile
# Symbols present in the vdso
vdso-syms = rt_sigreturn
ifdef CONFIG_64BIT
vdso-syms += gettimeofday
vdso-syms += clock_gettime
vdso-syms += clock_getres
endif
vdso-syms += getcpu
vdso-syms += flush_icache
# Files to link into the vdso
obj-vdso = $(patsubst %, %.o, $(vdso-syms))
# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
obj-y += vdso.o vdso-syms.o
CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
# Disable gcov profiling for VDSO code
GCOV_PROFILE := n
# Force dependency
$(obj)/vdso.o: $(obj)/vdso.so
# link rule for the .so file, .lds has to be first
SYSCFLAGS_vdso.so.dbg = $(c_flags)
$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
# We also create a special relocatable object that should mirror the symbol
# table and layout of the linked DSO. With ld --just-symbols we can then
# refer to these symbols in the kernel code rather than hand-coded addresses.
SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-Wl,--build-id -Wl,--hash-style=both
$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
$(call if_changed,vdsold)
LDFLAGS_vdso-syms.o := -r --just-symbols
$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
$(call if_changed,ld)
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
# actual build commands
# The DSO images are built using a special linker script
# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
# Make sure only to export the intended __vdso_xxx symbol offsets.
quiet_cmd_vdsold = VDSOLD $@
cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
-Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
$(CROSS_COMPILE)objcopy \
$(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
rm $@.tmp
# install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@
cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
vdso.so: $(obj)/vdso.so.dbg
@mkdir -p $(MODLIB)/vdso
$(call cmd,vdso_install)
vdso_install: vdso.so
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