1 # SPDX-License-Identifier: GPL-2.0
6 # Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
7 # the inclusion of generic Makefile.
8 ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32
9 include $(srctree)/lib/vdso/Makefile
11 # Same as cc-*option, but using CC_COMPAT instead of CC
12 ifeq ($(CONFIG_CC_IS_CLANG), y)
15 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
18 cc32-option = $(call try-run,\
19 $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
20 cc32-disable-warning = $(call try-run,\
21 $(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
22 cc32-ldoption = $(call try-run,\
23 $(CC_COMPAT) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
24 cc32-as-instr = $(call try-run,\
25 printf "%b\n" "$(1)" | $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
27 # We cannot use the global flags to compile the vDSO files, the main reason
28 # being that the 32-bit compiler may be older than the main (64-bit) compiler
29 # and therefore may not understand flags set using $(cc-option ...). Besides,
30 # arch-specific options should be taken from the arm Makefile instead of the
32 # As a result we set our own flags here.
34 # KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
35 VDSO_CPPFLAGS := -D__KERNEL__ -nostdinc
36 VDSO_CPPFLAGS += -isystem $(shell $(CC_COMPAT) -print-file-name=include 2>/dev/null)
37 VDSO_CPPFLAGS += $(LINUXINCLUDE)
39 # Common C and assembly flags
40 # From top-level Makefile
41 VDSO_CAFLAGS := $(VDSO_CPPFLAGS)
42 ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),)
43 VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
46 VDSO_CAFLAGS += $(call cc32-option,-fno-PIE)
47 ifdef CONFIG_DEBUG_INFO
52 VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm)
53 VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft
54 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
55 VDSO_CAFLAGS += -mbig-endian
57 VDSO_CAFLAGS += -mlittle-endian
60 # From arm vDSO Makefile
61 VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
62 VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING
65 # Try to compile for ARMv8. If the compiler is too old and doesn't support it,
66 # fall back to v7. There is no easy way to check for what architecture the code
67 # is being compiled, so define a macro specifying that (see arch/arm/Makefile).
68 VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
69 -march=armv7-a -D__LINUX_ARM_ARCH__=7)
71 VDSO_CFLAGS := $(VDSO_CAFLAGS)
72 VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
73 # KBUILD_CFLAGS from top-level Makefile
74 VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
75 -fno-strict-aliasing -fno-common \
76 -Werror-implicit-function-declaration \
77 -Wno-format-security \
80 # Some useful compiler-dependent flags from top-level Makefile
81 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
82 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
83 VDSO_CFLAGS += $(call cc32-option,-fno-strict-overflow)
84 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
85 VDSO_CFLAGS += $(call cc32-option,-Werror=date-time)
86 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
88 # The 32-bit compiler does not provide 128-bit integers, which are used in
89 # some headers that are indirectly included from the vDSO code.
90 # This hack makes the compiler happy and should trigger a warning/error if
91 # variables of such type are referenced.
92 VDSO_CFLAGS += -D__uint128_t='void*'
93 # Silence some warnings coming from headers that operate on long's
94 # (on GCC 4.8 or older, there is unfortunately no way to silence this warning)
95 VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow)
96 VDSO_CFLAGS += -Wno-int-to-pointer-cast
98 VDSO_AFLAGS := $(VDSO_CAFLAGS)
99 VDSO_AFLAGS += -D__ASSEMBLY__
101 # Check for binutils support for dmb ishld
102 dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)
104 VDSO_CFLAGS += $(dmbinstr)
105 VDSO_AFLAGS += $(dmbinstr)
107 VDSO_LDFLAGS := $(VDSO_CPPFLAGS)
108 # From arm vDSO Makefile
109 VDSO_LDFLAGS += -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1
110 VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
111 VDSO_LDFLAGS += -nostdlib -shared -mfloat-abi=soft
112 VDSO_LDFLAGS += -Wl,--hash-style=sysv
113 VDSO_LDFLAGS += -Wl,--build-id
114 VDSO_LDFLAGS += $(call cc32-ldoption,-fuse-ld=bfd)
117 # Borrow vdsomunge.c from the arm vDSO
118 # We have to use a relative path because scripts/Makefile.host prefixes
119 # $(hostprogs-y) with $(obj)
120 munge := ../../../arm/vdso/vdsomunge
121 hostprogs-y := $(munge)
124 c-obj-vdso-gettimeofday := vgettimeofday.o
125 asm-obj-vdso := sigreturn.o
127 ifneq ($(c-gettimeofday-y),)
128 VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y)
131 VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
134 targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw
135 c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso))
136 c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday))
137 asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
138 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
142 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
144 # Force dependency (vdso.s includes vdso.so through incbin)
145 $(obj)/vdso.o: $(obj)/vdso.so
147 include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE
148 $(call if_changed,vdsosym)
150 # Strip rule for vdso.so
151 $(obj)/vdso.so: OBJCOPYFLAGS := -S
152 $(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE
153 $(call if_changed,objcopy)
155 $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE
156 $(call if_changed,vdsomunge)
158 # Link rule for the .so file, .lds has to be first
159 $(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE
160 $(call if_changed,vdsold_and_vdso_check)
162 # Compilation rules for the vDSO sources
163 $(c-obj-vdso): %.o: %.c FORCE
164 $(call if_changed_dep,vdsocc)
165 $(c-obj-vdso-gettimeofday): %.o: %.c FORCE
166 $(call if_changed_dep,vdsocc_gettimeofday)
167 $(asm-obj-vdso): %.o: %.S FORCE
168 $(call if_changed_dep,vdsoas)
170 # Actual build commands
171 quiet_cmd_vdsold_and_vdso_check = LD32 $@
172 cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check)
174 quiet_cmd_vdsold = LD32 $@
175 cmd_vdsold = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_LDFLAGS) \
176 -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@
177 quiet_cmd_vdsocc = CC32 $@
178 cmd_vdsocc = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $<
179 quiet_cmd_vdsocc_gettimeofday = CC32 $@
180 cmd_vdsocc_gettimeofday = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $<
181 quiet_cmd_vdsoas = AS32 $@
182 cmd_vdsoas = $(CC_COMPAT) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $<
184 quiet_cmd_vdsomunge = MUNGE $@
185 cmd_vdsomunge = $(obj)/$(munge) $< $@
187 # Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO)
188 gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh
189 quiet_cmd_vdsosym = VDSOSYM $@
190 # The AArch64 nm should be able to read an AArch32 binary
191 cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
193 # Install commands for the unstripped file
194 quiet_cmd_vdso_install = INSTALL32 $@
195 cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so
197 vdso.so: $(obj)/vdso.so.dbg
198 @mkdir -p $(MODLIB)/vdso
199 $(call cmd,vdso_install)
201 vdso_install: vdso.so