1 # SPDX-License-Identifier: GPL-2.0
2 # List of files in the vdso, has to be asm only for now
3 
4 ARCH_REL_TYPE_ABS := R_PPC_JUMP_SLOT|R_PPC_GLOB_DAT|R_PPC_ADDR32|R_PPC_ADDR24|R_PPC_ADDR16|R_PPC_ADDR16_LO|R_PPC_ADDR16_HI|R_PPC_ADDR16_HA|R_PPC_ADDR14|R_PPC_ADDR14_BRTAKEN|R_PPC_ADDR14_BRNTAKEN|R_PPC_REL24
5 include $(srctree)/lib/vdso/Makefile
6 
7 obj-vdso64 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o getcpu.o
8 
9 ifneq ($(c-gettimeofday-y),)
10   CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
11   CFLAGS_vgettimeofday.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
12   CFLAGS_vgettimeofday.o += $(call cc-option, -fno-stack-protector)
13   CFLAGS_vgettimeofday.o += -DDISABLE_BRANCH_PROFILING
14   CFLAGS_vgettimeofday.o += -ffreestanding -fasynchronous-unwind-tables
15   CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
16 endif
17 
18 # Build rules
19 
20 targets := $(obj-vdso64) vdso64.so.dbg vgettimeofday.o
21 obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
22 
23 GCOV_PROFILE := n
24 KCOV_INSTRUMENT := n
25 UBSAN_SANITIZE := n
26 KASAN_SANITIZE := n
27 
28 ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
29 	-Wl,-soname=linux-vdso64.so.1 -Wl,--hash-style=both
30 
31 # Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true
32 # by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is
33 # compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code
34 # generation is minimal, it will just use r29 instead.
35 ccflags-y += $(call cc-option, -ffixed-r30)
36 
37 asflags-y := -D__VDSO64__ -s
38 
39 targets += vdso64.lds
40 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
41 
42 # link rule for the .so file, .lds has to be first
43 $(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday.o FORCE
44 	$(call if_changed,vdso64ld_and_check)
45 
46 # Generate VDSO offsets using helper script
47 gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
48 quiet_cmd_vdsosym = VDSOSYM $@
49       cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
50 
51 include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE
52 	$(call if_changed,vdsosym)
53 
54 # actual build commands
55 quiet_cmd_vdso64ld_and_check = VDSO64L $@
56       cmd_vdso64ld_and_check = $(CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
57