arch/mips/vdso/Makefile

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

File Facts

System
Linux kernel
Corpus path
arch/mips/vdso/Makefile
Extension
[no extension]
Size
5797 bytes
Lines
198
Domain
Architecture Layer
Bucket
arch/mips
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
# Objects to go into the VDSO.

# Include the generic Makefile to check the built vdso.
include $(srctree)/lib/vdso/Makefile.include

obj-vdso-y := elf.o sigreturn.o

# Common compiler flags between ABIs.
ccflags-vdso := \
	$(filter -I%,$(KBUILD_CFLAGS)) \
	$(filter -E%,$(KBUILD_CFLAGS)) \
	$(filter -mmicromips,$(KBUILD_CFLAGS)) \
	$(filter -march=%,$(KBUILD_CFLAGS)) \
	$(filter -m%-float,$(KBUILD_CFLAGS)) \
	$(filter -mno-loongson-%,$(KBUILD_CFLAGS)) \
	$(CLANG_FLAGS) \
	-D__VDSO__

ifndef CONFIG_64BIT
ccflags-vdso += -DBUILD_VDSO32
endif

#
# The -fno-jump-tables flag only prevents the compiler from generating
# jump tables but does not prevent the compiler from emitting absolute
# offsets.
cflags-vdso := $(ccflags-vdso) \
	$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
	$(filter -std=%,$(KBUILD_CFLAGS)) \
	-O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
	-mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \
	-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
	$(call cc-option, -fno-asynchronous-unwind-tables)
aflags-vdso := $(ccflags-vdso) \
	-D__ASSEMBLY__ -Wa,-gdwarf-2

ifneq ($(c-gettimeofday-y),)
obj-vdso-y += vgettimeofday.o
CFLAGS_vgettimeofday.o = -include $(c-gettimeofday-y)

# config-n32-o32-env.c prepares the environment to build a 32bit vDSO
# library on a 64bit kernel.
# Note: Needs to be included before than the generic library.
CFLAGS_vgettimeofday-o32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday-n32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
endif

CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)

# VDSO linker flags.
ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
	$(filter -E%,$(KBUILD_CFLAGS)) -shared \
	-G 0 --eh-frame-hdr --hash-style=sysv --build-id=sha1 -T

CFLAGS_REMOVE_vdso.o = $(CC_FLAGS_FTRACE)

# Check that we don't have PIC 'jalr t9' calls left
quiet_cmd_vdso_mips_check = VDSOCHK $@
      cmd_vdso_mips_check = if $(OBJDUMP) --disassemble $@ | grep -E -h "jalr.*t9" > /dev/null; \
		       then (echo >&2 "$@: PIC 'jalr t9' calls are not supported"; \
			     rm -f $@; /bin/false); fi

#
# Shared build commands.
#

quiet_cmd_vdsold_and_vdso_check = LD      $@
      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check); $(cmd_vdso_mips_check)

Annotation

Implementation Notes