1# SPDX-License-Identifier: GPL-2.0
2# Objects to go into the VDSO.
3
4# Include the generic Makefile to check the built vdso.
5include $(srctree)/lib/vdso/Makefile
6
7obj-vdso-y := elf.o vgetcpu.o vgettimeofday.o sigreturn.o
8
9# Common compiler flags between ABIs.
10ccflags-vdso := \
11	$(filter -I%,$(KBUILD_CFLAGS)) \
12	$(filter -E%,$(KBUILD_CFLAGS)) \
13	$(filter -march=%,$(KBUILD_CFLAGS)) \
14	$(filter -m%-float,$(KBUILD_CFLAGS)) \
15	$(CLANG_FLAGS) \
16	-D__VDSO__
17
18cflags-vdso := $(ccflags-vdso) \
19	-isystem $(shell $(CC) -print-file-name=include) \
20	$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
21	-O2 -g -fno-strict-aliasing -fno-common -fno-builtin \
22	-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
23	$(call cc-option, -fno-asynchronous-unwind-tables) \
24	$(call cc-option, -fno-stack-protector)
25aflags-vdso := $(ccflags-vdso) \
26	-D__ASSEMBLY__ -Wa,-gdwarf-2
27
28ifneq ($(c-gettimeofday-y),)
29  CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
30endif
31
32# VDSO linker flags.
33ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
34	$(filter -E%,$(KBUILD_CFLAGS)) -nostdlib -shared \
35	--hash-style=sysv --build-id -T
36
37#
38# Shared build commands.
39#
40
41quiet_cmd_vdsold_and_vdso_check = LD      $@
42      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
43
44quiet_cmd_vdsoas_o_S = AS       $@
45      cmd_vdsoas_o_S = $(CC) $(a_flags) -c -o $@ $<
46
47# Generate VDSO offsets using helper script
48gen-vdsosym := $(src)/gen_vdso_offsets.sh
49quiet_cmd_vdsosym = VDSOSYM $@
50      cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
51
52include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
53	$(call if_changed,vdsosym)
54
55#
56# Build native VDSO.
57#
58
59native-abi := $(filter -mabi=%,$(KBUILD_CFLAGS))
60
61targets += $(obj-vdso-y)
62targets += vdso.lds vdso.so.dbg vdso.so
63
64obj-vdso := $(obj-vdso-y:%.o=$(obj)/%.o)
65
66$(obj-vdso): KBUILD_CFLAGS := $(cflags-vdso) $(native-abi)
67$(obj-vdso): KBUILD_AFLAGS := $(aflags-vdso) $(native-abi)
68
69$(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi)
70
71$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
72	$(call if_changed,vdsold_and_vdso_check)
73
74$(obj)/vdso.so: OBJCOPYFLAGS := -S
75$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
76	$(call if_changed,objcopy)
77
78obj-y += vdso.o
79
80$(obj)/vdso.o : $(obj)/vdso.so
81