Revision 300f786b2683f8bb1ec0afb6e1851183a479c86d authored by Cyrill Gorcunov on 07 June 2012, 21:21:12 UTC, committed by Linus Torvalds on 07 June 2012, 21:43:55 UTC
Zero is written at clear_tid_address when the process exits. This functionality is used by pthread_join(). We already have sys_set_tid_address() to change this address for the current task but there is no way to obtain it from user space. Without the ability to find this address and dump it we can't restore pthread'ed apps which call pthread_join() once they have been restored. This patch introduces the PR_GET_TID_ADDRESS prctl option which allows the current process to obtain own clear_tid_address. This feature is available iif CONFIG_CHECKPOINT_RESTORE is set. [akpm@linux-foundation.org: fix prctl numbering] Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pedro Alves <palves@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1ad75b9
Makefile_32.cpu
# CPU tuning section - shared with UML.
# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
#-mtune exists since gcc 3.4
HAS_MTUNE := $(call cc-option-yn, -mtune=i386)
ifeq ($(HAS_MTUNE),y)
tune = $(call cc-option,-mtune=$(1),$(2))
else
tune = $(call cc-option,-mcpu=$(1),$(2))
endif
align := $(cc-option-align)
cflags-$(CONFIG_M386) += -march=i386
cflags-$(CONFIG_M486) += -march=i486
cflags-$(CONFIG_M586) += -march=i586
cflags-$(CONFIG_M586TSC) += -march=i586
cflags-$(CONFIG_M586MMX) += -march=pentium-mmx
cflags-$(CONFIG_M686) += -march=i686
cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2)
cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3)
cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3)
cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4)
cflags-$(CONFIG_MK6) += -march=k6
# Please note, that patches that add -march=athlon-xp and friends are pointless.
# They make zero difference whatsosever to performance at this time.
cflags-$(CONFIG_MK7) += -march=athlon
cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon)
cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586)
cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586)
cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686)
cflags-$(CONFIG_MVIAC7) += -march=i686
cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2)
cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \
$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
# AMD Elan support
cflags-$(CONFIG_MELAN) += -march=i486
# Geode GX1 support
cflags-$(CONFIG_MGEODEGX1) += -march=pentium-mmx
cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx)
# add at the end to overwrite eventual tuning options from earlier
# cpu entries
cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686))
# Work around the pentium-mmx code generator madness of gcc4.4.x which
# does stack alignment by generating horrible code _before_ the mcount
# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph
# tracer assumptions. For i686, generic, core2 this is set by the
# compiler anyway
ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y)
ADD_ACCUMULATE_OUTGOING_ARGS := y
endif
# Work around to a bug with asm goto with first implementations of it
# in gcc causing gcc to mess up the push and pop of the stack in some
# uses of asm goto.
ifeq ($(CONFIG_JUMP_LABEL), y)
ADD_ACCUMULATE_OUTGOING_ARGS := y
endif
cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args)
# Bug fix for binutils: this option is required in order to keep
# binutils from generating NOPL instructions against our will.
ifneq ($(CONFIG_X86_P6_NOP),y)
cflags-y += $(call cc-option,-Wa$(comma)-mtune=generic32,)
endif
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