xref: /openbmc/linux/arch/riscv/kernel/vdso/Makefile (revision a2cab953)
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, $(vdso-syms)) note.o
18
19ccflags-y := -fno-stack-protector
20
21ifneq ($(c-gettimeofday-y),)
22  CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
23endif
24
25# Build rules
26targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds
27obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
28
29obj-y += vdso.o
30CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
31ifneq ($(filter vgettimeofday, $(vdso-syms)),)
32CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
33endif
34
35# Disable -pg to prevent insert call site
36CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
37
38# Disable profiling and instrumentation for VDSO code
39GCOV_PROFILE := n
40KCOV_INSTRUMENT := n
41KASAN_SANITIZE := n
42UBSAN_SANITIZE := n
43
44# Force dependency
45$(obj)/vdso.o: $(obj)/vdso.so
46
47# link rule for the .so file, .lds has to be first
48$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
49	$(call if_changed,vdsold)
50LDFLAGS_vdso.so.dbg = -shared -S -soname=linux-vdso.so.1 \
51	--build-id=sha1 --hash-style=both --eh-frame-hdr
52
53# strip rule for the .so file
54$(obj)/%.so: OBJCOPYFLAGS := -S
55$(obj)/%.so: $(obj)/%.so.dbg FORCE
56	$(call if_changed,objcopy)
57
58# Generate VDSO offsets using helper script
59gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
60quiet_cmd_vdsosym = VDSOSYM $@
61	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
62
63include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
64	$(call if_changed,vdsosym)
65
66# actual build commands
67# The DSO images are built using a special linker script
68# Make sure only to export the intended __vdso_xxx symbol offsets.
69quiet_cmd_vdsold = VDSOLD  $@
70      cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
71                   $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
72                   rm $@.tmp
73
74# install commands for the unstripped file
75quiet_cmd_vdso_install = INSTALL $@
76      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
77
78vdso.so: $(obj)/vdso.so.dbg
79	@mkdir -p $(MODLIB)/vdso
80	$(call cmd,vdso_install)
81
82vdso_install: vdso.so
83