linux-imx/arch/powerpc/kernel/vdso/Makefile

SPDX-License-Identifier: GPL-2.0

List of files in the vdso, has to be asm only for now

Include the generic Makefile to check the built vdso.

include $(srctree)/lib/vdso/Makefile

obj-vdso32 = sigtramp32-32.o gettimeofday-32.o datapage-32.o cacheflush-32.o note-32.o getcpu-32.o obj-vdso64 = sigtramp64-64.o gettimeofday-64.o datapage-64.o cacheflush-64.o note-64.o getcpu-64.o

ifneq ($(c-gettimeofday-y),) CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y) CFLAGS_vgettimeofday-32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_vgettimeofday-32.o += $(call cc-option, -fno-stack-protector) CFLAGS_vgettimeofday-32.o += -DDISABLE_BRANCH_PROFILING CFLAGS_vgettimeofday-32.o += -ffreestanding -fasynchronous-unwind-tables CFLAGS_REMOVE_vgettimeofday-32.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_vgettimeofday-32.o += -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc

This flag is supported by clang for 64-bit but not 32-bit so it will cause

an unused command line flag warning for this file.

ifdef CONFIG_CC_IS_CLANG CFLAGS_REMOVE_vgettimeofday-32.o += -fno-stack-clash-protection endif CFLAGS_vgettimeofday-64.o += -include $(c-gettimeofday-y) CFLAGS_vgettimeofday-64.o += $(DISABLE_LATENT_ENTROPY_PLUGIN) CFLAGS_vgettimeofday-64.o += $(call cc-option, -fno-stack-protector) CFLAGS_vgettimeofday-64.o += -DDISABLE_BRANCH_PROFILING CFLAGS_vgettimeofday-64.o += -ffreestanding -fasynchronous-unwind-tables CFLAGS_REMOVE_vgettimeofday-64.o = $(CC_FLAGS_FTRACE)

Go prior to 1.16.x assumes r30 is not clobbered by any VDSO code. That used to be true

by accident when the VDSO was hand-written asm code, but may not be now that the VDSO is

compiler generated. To avoid breaking Go tell GCC not to use r30. Impact on code

generation is minimal, it will just use r29 instead.

CFLAGS_vgettimeofday-64.o += $(call cc-option, -ffixed-r30) endif

Build rules

ifdef CROSS32_COMPILE VDSOCC := $(CROSS32_COMPILE)gcc else VDSOCC := $(CC) endif

targets := $(obj-vdso32) vdso32.so.dbg vgettimeofday-32.o obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32)) targets += $(obj-vdso64) vdso64.so.dbg vgettimeofday-64.o obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))

GCOV_PROFILE := n KCOV_INSTRUMENT := n UBSAN_SANITIZE := n KASAN_SANITIZE := n KCSAN_SANITIZE := n

ccflags-y := -fno-common -fno-builtin ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld) ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)

Filter flags that clang will warn are unused for linking

ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CFLAGS))

CC32FLAGS := -m32 LD32FLAGS := -Wl,-soname=linux-vdso32.so.1 AS32FLAGS := -D__VDSO32__

LD64FLAGS := -Wl,-soname=linux-vdso64.so.1 AS64FLAGS := -D__VDSO64__

targets += vdso32.lds CPPFLAGS_vdso32.lds += -P -C -Upowerpc targets += vdso64.lds CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)

link rule for the .so file, .lds has to be first

$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday-32.o FORCE $(call if_changed,vdso32ld_and_check) $(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday-64.o FORCE $(call if_changed,vdso64ld_and_check)

assembly rules for the .S files

$(obj-vdso32): %-32.o: %.S FORCE $(call if_changed_dep,vdso32as) $(obj)/vgettimeofday-32.o: %-32.o: %.c FORCE $(call if_changed_dep,vdso32cc) $(obj-vdso64): %-64.o: %.S FORCE $(call if_changed_dep,vdso64as) $(obj)/vgettimeofday-64.o: %-64.o: %.c FORCE $(call if_changed_dep,cc_o_c)

Generate VDSO offsets using helper script

gen-vdso32sym := $(srctree)/$(src)/gen_vdso32_offsets.sh quiet_cmd_vdso32sym = VDSO32SYM $@ cmd_vdso32sym = $(NM) $< | $(gen-vdso32sym) | LC_ALL=C sort > $@ gen-vdso64sym := $(srctree)/$(src)/gen_vdso64_offsets.sh quiet_cmd_vdso64sym = VDSO64SYM $@ cmd_vdso64sym = $(NM) $< | $(gen-vdso64sym) | LC_ALL=C sort > $@

include/generated/vdso32-offsets.h: $(obj)/vdso32.so.dbg FORCE $(call if_changed,vdso32sym) include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE $(call if_changed,vdso64sym)

actual build commands

quiet_cmd_vdso32ld_and_check = VDSO32L $@ cmd_vdso32ld_and_check = $(VDSOCC) $(ldflags-y) $(CC32FLAGS) $(LD32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) quiet_cmd_vdso32as = VDSO32A $@ cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $< quiet_cmd_vdso32cc = VDSO32C $@ cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $<

quiet_cmd_vdso64ld_and_check = VDSO64L $@ cmd_vdso64ld_and_check = $(VDSOCC) $(ldflags-y) $(LD64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) quiet_cmd_vdso64as = VDSO64A $@ cmd_vdso64as = $(VDSOCC) $(a_flags) $(AS64FLAGS) -c -o $@ $<

OBJECT_FILES_NON_STANDARD := y