xref: /linux/arch/riscv/kernel/vdso/Makefile (revision 37f57bd3faeac92e898c3381355f4fd2b6a80901)
1# SPDX-License-Identifier: GPL-2.0-only
2# Copied from arch/tile/kernel/vdso/Makefile
3
4# Include the generic Makefile to check the built vdso.
5include $(srctree)/lib/vdso/Makefile.include
6# Symbols present in the vdso
7vdso-syms  = rt_sigreturn
8ifdef CONFIG_64BIT
9vdso-syms += vgettimeofday
10endif
11vdso-syms += getcpu
12vdso-syms += flush_icache
13vdso-syms += hwprobe
14vdso-syms += sys_hwprobe
15
16ifdef CONFIG_VDSO_GETRANDOM
17vdso-syms += getrandom
18endif
19
20ifdef VDSO_CFI_BUILD
21CFI_MARCH = _zicfilp_zicfiss
22CFI_FULL = -fcf-protection=full
23endif
24
25# Files to link into the vdso
26obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
27
28ifdef CONFIG_VDSO_GETRANDOM
29obj-vdso += vgetrandom-chacha.o
30endif
31
32ccflags-y := -fno-stack-protector
33ccflags-y += -DDISABLE_BRANCH_PROFILING
34ccflags-y += -fno-builtin
35ccflags-y += $(KBUILD_BASE_ISA)$(CFI_MARCH)
36ccflags-y += $(CFI_FULL)
37asflags-y += $(KBUILD_BASE_ISA)$(CFI_MARCH)
38asflags-y += $(CFI_FULL)
39
40ifneq ($(c-gettimeofday-y),)
41  CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
42endif
43
44ifneq ($(c-getrandom-y),)
45  CFLAGS_getrandom.o += -fPIC -include $(c-getrandom-y)
46endif
47
48CFLAGS_hwprobe.o += -fPIC
49
50# Build rules
51targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds
52obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
53
54obj-y += vdso.o
55CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
56ifneq ($(filter vgettimeofday, $(vdso-syms)),)
57CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
58endif
59
60# Disable -pg to prevent insert call site
61CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
62CFLAGS_REMOVE_getrandom.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
63CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
64
65# Force dependency
66$(obj)/vdso.o: $(obj)/vdso.so
67
68# link rule for the .so file, .lds has to be first
69$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
70	$(call if_changed,vdsold_and_check)
71LDFLAGS_vdso.so.dbg = -shared -soname=linux-vdso.so.1 \
72	--build-id=sha1 --eh-frame-hdr
73
74# strip rule for the .so file
75$(obj)/%.so: OBJCOPYFLAGS := -S
76$(obj)/%.so: $(obj)/%.so.dbg FORCE
77	$(call if_changed,objcopy)
78
79# Generate VDSO offsets using helper script
80gen-vdsosym := $(src)/gen_vdso_offsets.sh
81quiet_cmd_vdsosym = VDSOSYM $@
82	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
83
84include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
85	$(call if_changed,vdsosym)
86
87# actual build commands
88# The DSO images are built using a special linker script
89# Make sure only to export the intended __vdso_xxx symbol offsets.
90quiet_cmd_vdsold_and_check = VDSOLD  $@
91      cmd_vdsold_and_check = $(LD) $(CFI_FULL) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
92                   $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
93                   rm $@.tmp && \
94                   $(cmd_vdso_check)
95