xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision fb37409a)
1# SPDX-License-Identifier: GPL-2.0-only
2# Copied from arch/tile/kernel/vdso/Makefile
3
4# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
5# the inclusion of generic Makefile.
6ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
7include $(srctree)/lib/vdso/Makefile
8# Symbols present in the vdso
9vdso-syms  = rt_sigreturn
10ifdef CONFIG_64BIT
11vdso-syms += vgettimeofday
12endif
13vdso-syms += getcpu
14vdso-syms += flush_icache
15
16# Files to link into the vdso
17obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
18
19ifneq ($(c-gettimeofday-y),)
20  CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
21endif
22
23# Build rules
24targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
25obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
26
27obj-y += vdso.o vdso-syms.o
28CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
29
30# Disable -pg to prevent insert call site
31CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
32
33# Disable gcov profiling for VDSO code
34GCOV_PROFILE := n
35
36# Force dependency
37$(obj)/vdso.o: $(obj)/vdso.so
38
39# link rule for the .so file, .lds has to be first
40SYSCFLAGS_vdso.so.dbg = $(c_flags)
41$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
42	$(call if_changed,vdsold)
43
44# We also create a special relocatable object that should mirror the symbol
45# table and layout of the linked DSO. With ld --just-symbols we can then
46# refer to these symbols in the kernel code rather than hand-coded addresses.
47
48SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
49	-Wl,--build-id -Wl,--hash-style=both
50$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
51	$(call if_changed,vdsold)
52
53LDFLAGS_vdso-syms.o := -r --just-symbols
54$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
55	$(call if_changed,ld)
56
57# strip rule for the .so file
58$(obj)/%.so: OBJCOPYFLAGS := -S
59$(obj)/%.so: $(obj)/%.so.dbg FORCE
60	$(call if_changed,objcopy)
61
62# actual build commands
63# The DSO images are built using a special linker script
64# Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
65# Make sure only to export the intended __vdso_xxx symbol offsets.
66quiet_cmd_vdsold = VDSOLD  $@
67      cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
68                           -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
69                   $(CROSS_COMPILE)objcopy \
70                           $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
71                   rm $@.tmp
72
73# install commands for the unstripped file
74quiet_cmd_vdso_install = INSTALL $@
75      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
76
77vdso.so: $(obj)/vdso.so.dbg
78	@mkdir -p $(MODLIB)/vdso
79	$(call cmd,vdso_install)
80
81vdso_install: vdso.so
82