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This implements new vDSO for x86-64. The concept is similar to the existing vDSOs on i386 and PPC. x86-64 has had static vsyscalls before, but these are not flexible enough anymore. A vDSO is a ELF shared library supplied by the kernel that is mapped into user address space. The vDSO mapping is randomized for each process for security reasons. Doing this was needed for clock_gettime, because clock_gettime always needs a syscall fallback and having one at a fixed address would have made buffer overflow exploits too easy to write. The vdso can be disabled with vdso=0 It currently includes a new gettimeofday implemention and optimized clock_gettime(). The gettimeofday implementation is slightly faster than the one in the old vsyscall. clock_gettime is significantly faster than the syscall for CLOCK_MONOTONIC and CLOCK_REALTIME. The new calls are generally faster than the old vsyscall. Advantages over the old x86-64 vsyscalls: - Extensible - Randomized - Cleaner - Easier to virtualize (the old static address range previously causes overhead e.g. for Xen because it has to create special page tables for it) Weak points: - glibc support still to be written The VM interface is partly based on Ingo Molnar's i386 version. Includes compile fix from Joachim Deguara Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
130 lines
4.5 KiB
Makefile
130 lines
4.5 KiB
Makefile
#
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# x86_64/Makefile
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#
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# This file is included by the global makefile so that you can add your own
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# architecture-specific flags and dependencies. Remember to do have actions
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# for "archclean" and "archdep" for cleaning up and making dependencies for
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# this architecture
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#
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# This file is subject to the terms and conditions of the GNU General Public
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# License. See the file "COPYING" in the main directory of this archive
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# for more details.
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#
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# Copyright (C) 1994 by Linus Torvalds
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#
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# 19990713 Artur Skawina <skawina@geocities.com>
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# Added '-march' and '-mpreferred-stack-boundary' support
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# 20000913 Pavel Machek <pavel@suse.cz>
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# Converted for x86_64 architecture
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# 20010105 Andi Kleen, add IA32 compiler.
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# ....and later removed it again....
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#
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# $Id: Makefile,v 1.31 2002/03/22 15:56:07 ak Exp $
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LDFLAGS := -m elf_x86_64
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OBJCOPYFLAGS := -O binary -R .note -R .comment -S
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LDFLAGS_vmlinux :=
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CHECKFLAGS += -D__x86_64__ -m64
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cflags-y :=
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cflags-kernel-y :=
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cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
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cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
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# gcc doesn't support -march=core2 yet as of gcc 4.3, but I hope it
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# will eventually. Use -mtune=generic as fallback
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cflags-$(CONFIG_MCORE2) += \
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$(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
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cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
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cflags-y += -m64
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cflags-y += -mno-red-zone
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cflags-y += -mcmodel=kernel
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cflags-y += -pipe
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cflags-y += -Wno-sign-compare
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cflags-y += -fno-asynchronous-unwind-tables
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ifneq ($(CONFIG_DEBUG_INFO),y)
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# -fweb shrinks the kernel a bit, but the difference is very small
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# it also messes up debugging, so don't use it for now.
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#cflags-y += $(call cc-option,-fweb)
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endif
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# -funit-at-a-time shrinks the kernel .text considerably
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# unfortunately it makes reading oopses harder.
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cflags-y += $(call cc-option,-funit-at-a-time)
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# prevent gcc from generating any FP code by mistake
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cflags-y += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
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# this works around some issues with generating unwind tables in older gccs
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# newer gccs do it by default
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cflags-y += -maccumulate-outgoing-args
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# do binutils support CFI?
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cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
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AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
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# is .cfi_signal_frame supported too?
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cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
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AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
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cflags-$(CONFIG_CC_STACKPROTECTOR) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh "$(CC)" -fstack-protector )
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cflags-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh "$(CC)" -fstack-protector-all )
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CFLAGS += $(cflags-y)
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CFLAGS_KERNEL += $(cflags-kernel-y)
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AFLAGS += -m64
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head-y := arch/x86_64/kernel/head.o arch/x86_64/kernel/head64.o arch/x86_64/kernel/init_task.o
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libs-y += arch/x86_64/lib/
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core-y += arch/x86_64/kernel/ \
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arch/x86_64/mm/ \
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arch/x86_64/crypto/ \
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arch/x86_64/vdso/
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core-$(CONFIG_IA32_EMULATION) += arch/x86_64/ia32/
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drivers-$(CONFIG_PCI) += arch/x86_64/pci/
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drivers-$(CONFIG_OPROFILE) += arch/x86_64/oprofile/
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boot := arch/x86_64/boot
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PHONY += bzImage bzlilo install archmrproper \
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fdimage fdimage144 fdimage288 isoimage archclean
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#Default target when executing "make"
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all: bzImage
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BOOTIMAGE := arch/x86_64/boot/bzImage
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KBUILD_IMAGE := $(BOOTIMAGE)
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bzImage: vmlinux
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$(Q)$(MAKE) $(build)=$(boot) $(BOOTIMAGE)
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bzlilo: vmlinux
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$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) zlilo
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bzdisk: vmlinux
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$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) zdisk
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fdimage fdimage144 fdimage288 isoimage: vmlinux
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$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@
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install:
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$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@
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archclean:
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$(Q)$(MAKE) $(clean)=$(boot)
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define archhelp
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echo '* bzImage - Compressed kernel image (arch/$(ARCH)/boot/bzImage)'
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echo ' install - Install kernel using'
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echo ' (your) ~/bin/installkernel or'
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echo ' (distribution) /sbin/installkernel or'
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echo ' install to $$(INSTALL_PATH) and run lilo'
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echo ' bzdisk - Create a boot floppy in /dev/fd0'
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echo ' fdimage - Create a boot floppy image'
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echo ' isoimage - Create a boot CD-ROM image'
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endef
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CLEAN_FILES += arch/$(ARCH)/boot/fdimage \
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arch/$(ARCH)/boot/image.iso \
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arch/$(ARCH)/boot/mtools.conf
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