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)
14 CC_COMPAT += --target=arm-linux-gnueabi
16 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
19 ifeq ($(CONFIG_LD_IS_LLD), y)
22 LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld
25 cc32-option = $(call try-run,\
26 $(CC_COMPAT) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
27 cc32-disable-warning = $(call try-run,\
28 $(CC_COMPAT) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
29 cc32-as-instr = $(call try-run,\
30 printf "%b\n" "$(1)" | $(CC_COMPAT) $(VDSO_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
32 # We cannot use the global flags to compile the vDSO files, the main reason
33 # being that the 32-bit compiler may be older than the main (64-bit) compiler
34 # and therefore may not understand flags set using $(cc-option ...). Besides,
35 # arch-specific options should be taken from the arm Makefile instead of the
37 # As a result we set our own flags here.
39 # KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile
40 VDSO_CPPFLAGS := -DBUILD_VDSO -D__KERNEL__ -nostdinc
41 VDSO_CPPFLAGS += -isystem $(shell $(CC_COMPAT) -print-file-name=include 2>/dev/null)
42 VDSO_CPPFLAGS += $(LINUXINCLUDE)
44 # Common C and assembly flags
45 # From top-level Makefile
46 VDSO_CAFLAGS := $(VDSO_CPPFLAGS)
47 VDSO_CAFLAGS += $(call cc32-option,-fno-PIE)
48 ifdef CONFIG_DEBUG_INFO
53 VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm)
54 VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft
55 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
56 VDSO_CAFLAGS += -mbig-endian
58 VDSO_CAFLAGS += -mlittle-endian
61 # From arm vDSO Makefile
62 VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector
63 VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING
66 # Try to compile for ARMv8. If the compiler is too old and doesn't support it,
67 # fall back to v7. There is no easy way to check for what architecture the code
68 # is being compiled, so define a macro specifying that (see arch/arm/Makefile).
69 VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\
70 -march=armv7-a -D__LINUX_ARM_ARCH__=7)
72 VDSO_CFLAGS := $(VDSO_CAFLAGS)
73 VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1
74 # KBUILD_CFLAGS from top-level Makefile
75 VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
76 -fno-strict-aliasing -fno-common \
77 -Werror-implicit-function-declaration \
78 -Wno-format-security \
81 # Some useful compiler-dependent flags from top-level Makefile
82 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
83 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
84 VDSO_CFLAGS += -fno-strict-overflow
85 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
86 VDSO_CFLAGS += -Werror=date-time
87 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
89 # The 32-bit compiler does not provide 128-bit integers, which are used in
90 # some headers that are indirectly included from the vDSO code.
91 # This hack makes the compiler happy and should trigger a warning/error if
92 # variables of such type are referenced.
93 VDSO_CFLAGS += -D__uint128_t='void*'
94 # Silence some warnings coming from headers that operate on long's
95 # (on GCC 4.8 or older, there is unfortunately no way to silence this warning)
96 VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow)
97 VDSO_CFLAGS += -Wno-int-to-pointer-cast
99 # Compile as THUMB2 or ARM. Unwinding via frame-pointers in THUMB2 is
101 ifeq ($(CONFIG_THUMB2_COMPAT_VDSO), y)
102 VDSO_CFLAGS += -mthumb -fomit-frame-pointer
107 VDSO_AFLAGS := $(VDSO_CAFLAGS)
108 VDSO_AFLAGS += -D__ASSEMBLY__
110 # Check for binutils support for dmb ishld
111 dmbinstr := $(call cc32-as-instr,dmb ishld,-DCONFIG_AS_DMB_ISHLD=1)
113 VDSO_CFLAGS += $(dmbinstr)
114 VDSO_AFLAGS += $(dmbinstr)
116 # From arm vDSO Makefile
117 VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1
118 VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096
119 VDSO_LDFLAGS += -nostdlib -shared --hash-style=sysv --build-id=sha1
122 # Borrow vdsomunge.c from the arm vDSO
123 # We have to use a relative path because scripts/Makefile.host prefixes
124 # $(hostprogs) with $(obj)
125 munge := ../../../arm/vdso/vdsomunge
126 hostprogs := $(munge)
129 c-obj-vdso-gettimeofday := vgettimeofday.o
131 ifneq ($(c-gettimeofday-y),)
132 VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y)
135 VDSO_CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
138 targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw
139 c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso))
140 c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday))
141 asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
142 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
145 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
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 = $(LD_COMPAT) $(VDSO_LDFLAGS) \
176 -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