1 # SPDX-License-Identifier: GPL-2.0-only
2 # Copied from arch/tile/kernel/vdso/Makefile
4 # Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
5 # the inclusion of generic Makefile.
6 ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
7 include $(srctree)/lib/vdso/Makefile
8 # Symbols present in the vdso
9 vdso-syms = rt_sigreturn
11 vdso-syms += vgettimeofday
14 vdso-syms += flush_icache
16 # Files to link into the vdso
17 obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
19 ccflags-y := -fno-stack-protector
21 ifneq ($(c-gettimeofday-y),)
22 CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
26 targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-syms.S
27 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
29 obj-y += vdso.o vdso-syms.o
30 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
32 # Disable -pg to prevent insert call site
33 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
35 # Disable profiling and instrumentation for VDSO code
41 $(obj)/vdso.o: $(obj)/vdso.so
43 # link rule for the .so file, .lds has to be first
44 $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
45 $(call if_changed,vdsold)
46 LDFLAGS_vdso.so.dbg = -shared -s -soname=linux-vdso.so.1 \
47 --build-id=sha1 --hash-style=both --eh-frame-hdr
49 # We also create a special relocatable object that should mirror the symbol
50 # table and layout of the linked DSO. With ld --just-symbols we can then
51 # refer to these symbols in the kernel code rather than hand-coded addresses.
52 $(obj)/vdso-syms.S: $(obj)/vdso.so FORCE
53 $(call if_changed,so2s)
55 # strip rule for the .so file
56 $(obj)/%.so: OBJCOPYFLAGS := -S
57 $(obj)/%.so: $(obj)/%.so.dbg FORCE
58 $(call if_changed,objcopy)
60 # actual build commands
61 # The DSO images are built using a special linker script
62 # Make sure only to export the intended __vdso_xxx symbol offsets.
63 quiet_cmd_vdsold = VDSOLD $@
64 cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
65 $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
68 # Extracts symbol offsets from the VDSO, converting them into an assembly file
69 # that contains the same symbols at the same offsets.
70 quiet_cmd_so2s = SO2S $@
71 cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@
73 # install commands for the unstripped file
74 quiet_cmd_vdso_install = INSTALL $@
75 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
77 vdso.so: $(obj)/vdso.so.dbg
78 @mkdir -p $(MODLIB)/vdso
79 $(call cmd,vdso_install)