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
)