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)/, $(obj-vdso))
20 btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti
22 # -Bsymbolic has been added for consistency with arm, the compat vDSO and
23 # potential future proofing if we end up with internal calls to the exported
24 # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
25 # preparation in build-time C")).
26 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
27 -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id=sha1 -n \
30 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
31 ccflags-y += -DDISABLE_BRANCH_PROFILING
33 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS)
36 OBJECT_FILES_NON_STANDARD := y
39 CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables
41 ifneq ($(c-gettimeofday-y),)
42 CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
45 # Disable gcov profiling for VDSO code
50 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
52 # Force dependency (incbin is bad)
53 $(obj)/vdso.o : $(obj)/vdso.so
55 # Link rule for the .so file, .lds has to be first
56 $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
57 $(call if_changed,vdsold_and_vdso_check)
59 # Strip rule for the .so file
60 $(obj)/%.so: OBJCOPYFLAGS := -S
61 $(obj)/%.so: $(obj)/%.so.dbg FORCE
62 $(call if_changed,objcopy)
64 # Generate VDSO offsets using helper script
65 gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
66 quiet_cmd_vdsosym = VDSOSYM $@
67 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
69 include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
70 $(call if_changed,vdsosym)
72 # Actual build commands
73 quiet_cmd_vdsold_and_vdso_check = LD $@
74 cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
76 # Install commands for the unstripped file
77 quiet_cmd_vdso_install = INSTALL $@
78 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
80 vdso.so: $(obj)/vdso.so.dbg
81 @mkdir -p $(MODLIB)/vdso
82 $(call cmd,vdso_install)