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 $(srctree)/lib/vdso/Makefile.include 7 8obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o 9obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o 10 11obj-vdso32 += getrandom-32.o vgetrandom-chacha-32.o 12obj-vdso64 += getrandom-64.o vgetrandom-chacha-64.o 13 14ifneq ($(c-gettimeofday-y),) 15 CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y) 16# Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true 17# by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is 18# compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code 19# generation is minimal, it will just use r29 instead. 20 CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y) $(call cc-option, -ffixed-r30) 21endif 22 23ifneq ($(c-getrandom-y),) 24 CFLAGS_vgetrandom-32.o += -include $(c-getrandom-y) 25 CFLAGS_vgetrandom-64.o += -include $(c-getrandom-y) 26endif 27 28# Build rules 29 30ifdef CROSS32_COMPILE 31 VDSOCC := $(CROSS32_COMPILE)gcc 32else 33 VDSOCC := $(CC) 34endif 35 36targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o vgetrandom-32.o 37targets += crtsavres-32.o 38obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32)) 39targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o vgetrandom-64.o 40obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64)) 41 42ccflags-y := -fno-common -fno-builtin -DBUILD_VDSO 43ccflags-y += $(DISABLE_LATENT_ENTROPY_PLUGIN) 44ccflags-y += $(call cc-option, -fno-stack-protector) 45ccflags-y += -DDISABLE_BRANCH_PROFILING 46ccflags-y += $(CONFIG_CC_OPT_INLINE_MEMSET) 47ccflags-y += -ffreestanding -fasynchronous-unwind-tables 48ccflags-remove-y := $(CC_FLAGS_FTRACE) 49ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS) 50ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld) 51ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) 52 53# Filter flags that clang will warn are unused for linking 54ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) 55 56CC32FLAGS := -m32 57CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc -mpcrel 58ifdef CONFIG_CC_IS_CLANG 59# This flag is supported by clang for 64-bit but not 32-bit so it will cause 60# an unused command line flag warning for this file. 61CC32FLAGSREMOVE += -fno-stack-clash-protection 62# -mstack-protector-guard values from the 64-bit build are not valid for the 63# 32-bit one. clang validates the values passed to these arguments during 64# parsing, even when -fno-stack-protector is passed afterwards. 65CC32FLAGSREMOVE += -mstack-protector-guard% 66# ftrace is disabled for the vdso but arch/powerpc/Makefile adds this define to 67# KBUILD_CPPFLAGS, which enables use of the 'patchable_function_entry' 68# attribute in the 'inline' define via 'notrace'. This attribute is not 69# supported for the powerpcle target, resulting in many instances of 70# -Wunknown-attributes. 71CC32FLAGSREMOVE += -DCC_USING_PATCHABLE_FUNCTION_ENTRY 72endif 73LD32FLAGS := -Wl,-soname=linux-vdso32.so.1 74AS32FLAGS := -D__VDSO32__ 75 76LD64FLAGS := -Wl,-soname=linux-vdso64.so.1 77AS64FLAGS := -D__VDSO64__ 78 79targets += vdso32.lds 80CPPFLAGS_vdso32.lds += -P -C -Upowerpc 81targets += vdso64.lds 82CPPFLAGS_vdso64.lds += -P -C 83 84# link rule for the .so file, .lds has to be first 85$(obj)/vdso32.so.dbg: $(obj)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o $(obj)/vgetrandom-32.o $(obj)/crtsavres-32.o FORCE 86 $(call if_changed,vdso32ld_and_check) 87$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o $(obj)/vgetrandom-64.o FORCE 88 $(call if_changed,vdso64ld_and_check) 89 90# assembly rules for the .S files 91$(obj-vdso32): %-32.o: %.S FORCE 92 $(call if_changed_dep,vdso32as) 93$(obj)/crtsavres-32.o: %-32.o: $(srctree)/arch/powerpc/lib/crtsavres.S FORCE 94 $(call if_changed_dep,vdso32as) 95$(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE 96 $(call if_changed_dep,vdso32cc) 97$(obj)/vgetrandom-32.o: %-32.o: %.c FORCE 98 $(call if_changed_dep,vdso32cc) 99$(obj-vdso64): %-64.o: %.S FORCE 100 $(call if_changed_dep,vdso64as) 101$(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE 102 $(call if_changed_dep,cc_o_c) 103$(obj)/vgetrandom-64.o: %-64.o: %.c FORCE 104 $(call if_changed_dep,cc_o_c) 105 106# Generate VDSO offsets using helper script 107gen-vdso32sym := $(src)/gen_vdso32_offsets.sh 108quiet_cmd_vdso32sym = VDSO32SYM $@ 109 cmd_vdso32sym = $(NM) $< | $(gen-vdso32sym) | LC_ALL=C sort > $@ 110gen-vdso64sym := $(src)/gen_vdso64_offsets.sh 111quiet_cmd_vdso64sym = VDSO64SYM $@ 112 cmd_vdso64sym = $(NM) $< | $(gen-vdso64sym) | LC_ALL=C sort > $@ 113 114include/generated/vdso32-offsets.h: $(obj)/vdso32.so.dbg FORCE 115 $(call if_changed,vdso32sym) 116include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE 117 $(call if_changed,vdso64sym) 118 119# actual build commands 120quiet_cmd_vdso32ld_and_check = VDSO32L $@ 121 cmd_vdso32ld_and_check = $(VDSOCC) $(ldflags-y) $(CC32FLAGS) $(LD32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) 122quiet_cmd_vdso32as = VDSO32A $@ 123 cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $< 124quiet_cmd_vdso32cc = VDSO32C $@ 125 cmd_vdso32cc = $(VDSOCC) $(filter-out $(CC32FLAGSREMOVE), $(c_flags)) $(CC32FLAGS) -c -o $@ $< 126 127quiet_cmd_vdso64ld_and_check = VDSO64L $@ 128 cmd_vdso64ld_and_check = $(VDSOCC) $(ldflags-y) $(LD64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) 129quiet_cmd_vdso64as = VDSO64A $@ 130 cmd_vdso64as = $(VDSOCC) $(a_flags) $(AS64FLAGS) -c -o $@ $< 131