arch/powerpc/kernel/vdso/Makefile

Source file repositories/reference/linux-study-clean/arch/powerpc/kernel/vdso/Makefile

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kernel/vdso/Makefile
Extension
[no extension]
Size
5661 bytes
Lines
130
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: build/configuration rule
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

# 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.include

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

obj-vdso32 += getrandom-32.o vgetrandom-chacha-32.o
obj-vdso64 += getrandom-64.o vgetrandom-chacha-64.o

ifneq ($(c-gettimeofday-y),)
  CFLAGS_vgettimeofday-32.o += -include $(c-gettimeofday-y)
# 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 += -include $(c-gettimeofday-y) $(call cc-option, -ffixed-r30)
endif

ifneq ($(c-getrandom-y),)
  CFLAGS_vgetrandom-32.o += -include $(c-getrandom-y)
  CFLAGS_vgetrandom-64.o += -include $(c-getrandom-y)
endif

# Build rules

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

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

ccflags-y := -fno-common -fno-builtin -DBUILD_VDSO
ccflags-y += $(DISABLE_LATENT_ENTROPY_PLUGIN)
ccflags-y += $(call cc-option, -fno-stack-protector)
ccflags-y += -DDISABLE_BRANCH_PROFILING
ccflags-y += -ffreestanding -fasynchronous-unwind-tables
ccflags-remove-y := $(CC_FLAGS_FTRACE)
ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack $(CLANG_FLAGS)
ldflags-$(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_CPPFLAGS) $(KBUILD_CFLAGS))

CC32FLAGS := -m32
CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc -mpcrel
ifdef CONFIG_CC_IS_CLANG
# 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.
CC32FLAGSREMOVE += -fno-stack-clash-protection
# -mstack-protector-guard values from the 64-bit build are not valid for the
# 32-bit one. clang validates the values passed to these arguments during
# parsing, even when -fno-stack-protector is passed afterwards.
CC32FLAGSREMOVE += -mstack-protector-guard%
# ftrace is disabled for the vdso but arch/powerpc/Makefile adds this define to
# KBUILD_CPPFLAGS, which enables use of the 'patchable_function_entry'
# attribute in the 'inline' define via 'notrace'. This attribute is not
# supported for the powerpcle target, resulting in many instances of
# -Wunknown-attributes.
CC32FLAGSREMOVE += -DCC_USING_PATCHABLE_FUNCTION_ENTRY

Annotation

Implementation Notes