1 # SPDX-License-Identifier: GPL-2.0
3 # Building a vDSO image for AArch64.
5 # Author: Will Deacon <will.deacon@arm.com>
6 # Heavily based on the vDSO Makefiles for other archs.
9 # Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
10 # the inclusion of generic Makefile.
11 ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64
12 include $(srctree)/lib/vdso/Makefile
14 obj-vdso := vgettimeofday.o note.o sigreturn.o
17 targets := $(obj-vdso) vdso.so vdso.so.dbg
18 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
20 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
23 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
24 ccflags-y += -DDISABLE_BRANCH_PROFILING
26 VDSO_LDFLAGS := -Bsymbolic
28 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
29 KBUILD_CFLAGS += $(DISABLE_LTO)
32 OBJECT_FILES_NON_STANDARD := y
35 ifeq ($(c-gettimeofday-y),)
36 CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny
38 CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -include $(c-gettimeofday-y)
41 # Clang versions less than 8 do not support -mcmodel=tiny
42 ifeq ($(CONFIG_CC_IS_CLANG), y)
43 ifeq ($(shell test $(CONFIG_CLANG_VERSION) -lt 80000; echo $$?),0)
44 CFLAGS_REMOVE_vgettimeofday.o += -mcmodel=tiny
48 # Disable gcov profiling for VDSO code
53 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
55 # Force dependency (incbin is bad)
56 $(obj)/vdso.o : $(obj)/vdso.so
58 # Link rule for the .so file, .lds has to be first
59 $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
61 $(call if_changed,vdso_check)
63 # Strip rule for the .so file
64 $(obj)/%.so: OBJCOPYFLAGS := -S
65 $(obj)/%.so: $(obj)/%.so.dbg FORCE
66 $(call if_changed,objcopy)
68 # Generate VDSO offsets using helper script
69 gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
70 quiet_cmd_vdsosym = VDSOSYM $@
71 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
73 include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
74 $(call if_changed,vdsosym)
76 # Actual build commands
77 quiet_cmd_vdsocc = VDSOCC $@
78 cmd_vdsocc = $(CC) $(a_flags) $(c_flags) -c -o $@ $<
80 # Install commands for the unstripped file
81 quiet_cmd_vdso_install = INSTALL $@
82 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
84 vdso.so: $(obj)/vdso.so.dbg
85 @mkdir -p $(MODLIB)/vdso
86 $(call cmd,vdso_install)