1# SPDX-License-Identifier: GPL-2.0
2
3# List of files in the vdso, has to be asm only for now
4
5# Include the generic Makefile to check the built vdso.
6include $(srctree)/lib/vdso/Makefile
7
8obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o
9obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o
10
11ifneq ($(c-gettimeofday-y),)
12  CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
13  CFLAGS_vgettimeofday-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
14  CFLAGS_vgettimeofday-32.o += $(call cc-option, -fno-stack-protector)
15  CFLAGS_vgettimeofday-32.o += -DDISABLE_BRANCH_PROFILING
16  CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables
17  CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE)
18  CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
19  # This flag is supported by clang for 64-bit but not 32-bit so it will cause
20  # an unused command line flag warning for this file.
21  ifdef CONFIG_CC_IS_CLANG
22  CFLAGS_REMOVE_vgettimeofday-32.o += -fno-stack-clash-protection
23  endif
24  CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y)
25  CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
26  CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector)
27  CFLAGS_vgettimeofday-64.o += -DDISABLE_BRANCH_PROFILING
28  CFLAGS_vgettimeofday-64.o += -ffreestanding -fasynchronous-unwind-tables
29  CFLAGS_REMOVE_vgettimeofday-64.o = $(CC_FLAGS_FTRACE)
30# Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true
31# by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is
32# compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code
33# generation is minimal, it will just use r29 instead.
34  CFLAGS_vgettimeofday-64.o += $(call cc-option, -ffixed-r30)
35endif
36
37# Build rules
38
39ifdef CROSS32_COMPILE
40    VDSOCC := $(CROSS32_COMPILE)gcc
41else
42    VDSOCC := $(CC)
43endif
44
45targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o
46obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
47targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o
48obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
49
50GCOV_PROFILE := n
51KCOV_INSTRUMENT := n
52UBSAN_SANITIZE := n
53KASAN_SANITIZE := n
54KCSAN_SANITIZE := n
55
56ccflags-y := -fno-common -fno-builtin
57ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS)
58ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld)
59ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
60
61# Filter flags that clang will warn are unused for linking
62ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CFLAGS))
63
64CC32FLAGS := -m32
65LD32FLAGS := -Wl,-soname=linux-vdso32.so.1
66AS32FLAGS := -D__VDSO32__
67
68LD64FLAGS := -Wl,-soname=linux-vdso64.so.1
69AS64FLAGS := -D__VDSO64__
70
71targets += vdso32.lds
72CPPFLAGS_vdso32.lds += -P -C -Upowerpc
73targets += vdso64.lds
74CPPFLAGS_vdso64.lds += -P -C
75
76# link rule for the .so file, .lds has to be first
77$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o FORCE
78	$(call if_changed,vdso32ld_and_check)
79$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o FORCE
80	$(call if_changed,vdso64ld_and_check)
81
82# assembly rules for the .S files
83$(obj-vdso32): %-32.o: %.S FORCE
84	$(call if_changed_dep,vdso32as)
85$(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE
86	$(call if_changed_dep,vdso32cc)
87$(obj-vdso64): %-64.o: %.S FORCE
88	$(call if_changed_dep,vdso64as)
89$(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE
90	$(call if_changed_dep,cc_o_c)
91
92# Generate VDSO offsets using helper script
93gen-vdso32sym := $(srctree)/$(src)/gen_vdso32_offsets.sh
94quiet_cmd_vdso32sym = VDSO32SYM $@
95      cmd_vdso32sym = $(NM) $< | $(gen-vdso32sym) | LC_ALL=C sort > $@
96gen-vdso64sym := $(srctree)/$(src)/gen_vdso64_offsets.sh
97quiet_cmd_vdso64sym = VDSO64SYM $@
98      cmd_vdso64sym = $(NM) $< | $(gen-vdso64sym) | LC_ALL=C sort > $@
99
100include/generated/vdso32-offsets.h: $(obj)/vdso32.so.dbg FORCE
101	$(call if_changed,vdso32sym)
102include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE
103	$(call if_changed,vdso64sym)
104
105# actual build commands
106quiet_cmd_vdso32ld_and_check = VDSO32L $@
107      cmd_vdso32ld_and_check = $(VDSOCC) $(ldflags-y) $(CC32FLAGS) $(LD32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
108quiet_cmd_vdso32as = VDSO32A $@
109      cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $<
110quiet_cmd_vdso32cc = VDSO32C $@
111      cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $<
112
113quiet_cmd_vdso64ld_and_check = VDSO64L $@
114      cmd_vdso64ld_and_check = $(VDSOCC) $(ldflags-y) $(LD64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
115quiet_cmd_vdso64as = VDSO64A $@
116      cmd_vdso64as = $(VDSOCC) $(a_flags) $(AS64FLAGS) -c -o $@ $<
117
118OBJECT_FILES_NON_STANDARD := y
119