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) $(CC_FLAGS_SCS)
41
42# Disable profiling and instrumentation for VDSO code
43GCOV_PROFILE := n
44KCOV_INSTRUMENT := n
45KASAN_SANITIZE := n
46UBSAN_SANITIZE := n
47
48# Force dependency
49$(obj)/vdso.o: $(obj)/vdso.so
50
51# link rule for the .so file, .lds has to be first
52$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
53	$(call if_changed,vdsold)
54LDFLAGS_vdso.so.dbg = -shared -S -soname=linux-vdso.so.1 \
55	--build-id=sha1 --hash-style=both --eh-frame-hdr
56
57# strip rule for the .so file
58$(obj)/%.so: OBJCOPYFLAGS := -S
59$(obj)/%.so: $(obj)/%.so.dbg FORCE
60	$(call if_changed,objcopy)
61
62# Generate VDSO offsets using helper script
63gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
64quiet_cmd_vdsosym = VDSOSYM $@
65	cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
66
67include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
68	$(call if_changed,vdsosym)
69
70# actual build commands
71# The DSO images are built using a special linker script
72# Make sure only to export the intended __vdso_xxx symbol offsets.
73quiet_cmd_vdsold = VDSOLD  $@
74      cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
75                   $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
76                   rm $@.tmp
77