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
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
16# Files to link into the vdso
17obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
18
19ccflags-y := -fno-stack-protector
20ccflags-y += -DDISABLE_BRANCH_PROFILING
21
22ifneq ($(c-gettimeofday-y),)
23  CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
24endif
25
26CFLAGS_hwprobe.o += -fPIC
27
28# Build rules
29targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds
30obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
31
32obj-y += vdso.o
33CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
34ifneq ($(filter vgettimeofday, $(vdso-syms)),)
35CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
36endif
37
38# Disable -pg to prevent insert call site
39CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
40CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS)
41
42# Force dependency
43$(obj)/vdso.o: $(obj)/vdso.so
44
45# link rule for the .so file, .lds has to be first
46$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
47	$(call if_changed,vdsold)
48LDFLAGS_vdso.so.dbg = -shared -S -soname=linux-vdso.so.1 \
49	--build-id=sha1 --hash-style=both --eh-frame-hdr
50
51# strip rule for the .so file
52$(obj)/%.so: OBJCOPYFLAGS := -S
53$(obj)/%.so: $(obj)/%.so.dbg FORCE
54	$(call if_changed,objcopy)
55
56# Generate VDSO offsets using helper script
57gen-vdsosym := $(src)/gen_vdso_offsets.sh
58quiet_cmd_vdsosym = VDSOSYM $@
59	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
60
61include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
62	$(call if_changed,vdsosym)
63
64# actual build commands
65# The DSO images are built using a special linker script
66# Make sure only to export the intended __vdso_xxx symbol offsets.
67quiet_cmd_vdsold = VDSOLD  $@
68      cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
69                   $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
70                   rm $@.tmp
71