xref: /linux/arch/riscv/kernel/vdso/Makefile (revision d30c1683aaecb93d2ab95685dc4300a33d3cea7a)
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
23CFI_SUFFIX = -cfi
24OFFSET_SUFFIX = _cfi
25ccflags-y += -DVDSO_CFI=1
26asflags-y += -DVDSO_CFI=1
27endif
28
29# Files to link into the vdso
30obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
31
32ifdef CONFIG_VDSO_GETRANDOM
33obj-vdso += vgetrandom-chacha.o
34endif
35
36ccflags-y := -fno-stack-protector
37ccflags-y += -DDISABLE_BRANCH_PROFILING
38ccflags-y += -fno-builtin
39ccflags-y += $(KBUILD_BASE_ISA)$(CFI_MARCH)
40ccflags-y += $(CFI_FULL)
41asflags-y += $(KBUILD_BASE_ISA)$(CFI_MARCH)
42asflags-y += $(CFI_FULL)
43
44ifneq ($(c-gettimeofday-y),)
45  CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
46endif
47
48ifneq ($(c-getrandom-y),)
49  CFLAGS_getrandom.o += -fPIC -include $(c-getrandom-y)
50endif
51
52CFLAGS_hwprobe.o += -fPIC
53
54# Build rules
55vdso_offsets := vdso$(if $(VDSO_CFI_BUILD),$(CFI_SUFFIX),)-offsets.h
56vdso_o := vdso$(if $(VDSO_CFI_BUILD),$(CFI_SUFFIX),).o
57vdso_so := vdso$(if $(VDSO_CFI_BUILD),$(CFI_SUFFIX),).so
58vdso_so_dbg := vdso$(if $(VDSO_CFI_BUILD),$(CFI_SUFFIX),).so.dbg
59vdso_lds := vdso.lds
60
61targets := $(obj-vdso) $(vdso_so) $(vdso_so_dbg) $(vdso_lds)
62
63obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
64
65obj-y += vdso$(if $(VDSO_CFI_BUILD),$(CFI_SUFFIX),).o
66CPPFLAGS_$(vdso_lds) += -P -C -U$(ARCH)
67ifneq ($(filter vgettimeofday, $(vdso-syms)),)
68CPPFLAGS_$(vdso_lds) += -DHAS_VGETTIMEOFDAY
69endif
70
71# Disable -pg to prevent insert call site
72CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
73CFLAGS_REMOVE_getrandom.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
74CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
75
76# Force dependency
77$(obj)/$(vdso_o): $(obj)/$(vdso_so)
78
79# link rule for the .so file, .lds has to be first
80$(obj)/$(vdso_so_dbg): $(obj)/$(vdso_lds) $(obj-vdso) FORCE
81	$(call if_changed,vdsold_and_check)
82LDFLAGS_$(vdso_so_dbg) = -shared -soname=linux-vdso.so.1 \
83	--build-id=sha1 --eh-frame-hdr
84
85# strip rule for the .so file
86$(obj)/%.so: OBJCOPYFLAGS := -S
87$(obj)/%.so: $(obj)/%.so.dbg FORCE
88	$(call if_changed,objcopy)
89
90# Generate VDSO offsets using helper script
91gen-vdsosym := $(src)/gen_vdso_offsets.sh
92quiet_cmd_vdsosym = VDSOSYM $@
93	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) $(OFFSET_SUFFIX) | LC_ALL=C sort > $@
94
95include/generated/$(vdso_offsets): $(obj)/$(vdso_so_dbg) FORCE
96	$(call if_changed,vdsosym)
97
98# actual build commands
99# The DSO images are built using a special linker script
100# Make sure only to export the intended __vdso_xxx symbol offsets.
101quiet_cmd_vdsold_and_check = VDSOLD  $@
102      cmd_vdsold_and_check = $(LD) $(CFI_FULL) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
103                   $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
104                   rm $@.tmp && \
105                   $(cmd_vdso_check)
106