Revision eb35bdd7bca29a13c8ecd44e6fd747a84ce675db authored by Will Deacon on 11 September 2014, 13:38:16 UTC, committed by Will Deacon on 11 September 2014, 17:34:58 UTC
Nathan reports that we leak TLS information from the parent context
during an exec, as we don't clear the TLS registers when flushing the
thread state.

This patch updates the flushing code so that we:

  (1) Unconditionally zero the tpidr_el0 register (since this is fully
      context switched for native tasks and zeroed for compat tasks)

  (2) Zero the tp_value state in thread_info before clearing the
      tpidrr0_el0 register for compat tasks (since this is only writable
      by the set_tls compat syscall and therefore not fully switched).

A missing compiler barrier is also added to the compat set_tls syscall.

Cc: <stable@vger.kernel.org>
Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 3d8afe3
Raw File
Makefile.headersinst
# ==========================================================================
# Installing headers
#
# header-y  - list files to be installed. They are preprocessed
#             to remove __KERNEL__ section of the file
# genhdr-y  - Same as header-y but in a generated/ directory
#
# ==========================================================================

# generated header directory
gen := $(if $(gen),$(gen),$(subst include/,include/generated/,$(obj)))

kbuild-file := $(srctree)/$(obj)/Kbuild
include $(kbuild-file)

# called may set destination dir (when installing to asm/)
_dst := $(if $(destination-y),$(destination-y),$(if $(dst),$(dst),$(obj)))

old-kbuild-file := $(srctree)/$(subst uapi/,,$(obj))/Kbuild
ifneq ($(wildcard $(old-kbuild-file)),)
include $(old-kbuild-file)
endif

include scripts/Kbuild.include

installdir    := $(INSTALL_HDR_PATH)/$(subst uapi/,,$(_dst))

header-y      := $(sort $(header-y))
subdirs       := $(patsubst %/,%,$(filter %/, $(header-y)))
header-y      := $(filter-out %/, $(header-y))

# files used to track state of install/check
install-file  := $(installdir)/.install
check-file    := $(installdir)/.check

# generic-y list all files an architecture uses from asm-generic
# Use this to build a list of headers which require a wrapper
wrapper-files := $(filter $(header-y), $(generic-y))

srcdir        := $(srctree)/$(obj)
gendir        := $(objtree)/$(gen)

oldsrcdir     := $(srctree)/$(subst /uapi,,$(obj))

# all headers files for this dir
header-y      := $(filter-out $(generic-y), $(header-y))
all-files     := $(header-y) $(genhdr-y) $(wrapper-files)
output-files  := $(addprefix $(installdir)/, $(all-files))

input-files1  := $(foreach hdr, $(header-y), \
		   $(if $(wildcard $(srcdir)/$(hdr)), \
			$(wildcard $(srcdir)/$(hdr))) \
		   )
input-files1-name := $(notdir $(input-files1))
input-files2  := $(foreach hdr, $(header-y), \
		   $(if  $(wildcard $(srcdir)/$(hdr)),, \
			$(if $(wildcard $(oldsrcdir)/$(hdr)), \
				$(wildcard $(oldsrcdir)/$(hdr)), \
				$(error Missing UAPI file $(srcdir)/$(hdr))) \
		   ))
input-files2-name := $(notdir $(input-files2))
input-files3  := $(foreach hdr, $(genhdr-y), \
		   $(if	$(wildcard $(gendir)/$(hdr)), \
			$(wildcard $(gendir)/$(hdr)), \
			$(error Missing generated UAPI file $(gendir)/$(hdr)) \
		   ))
input-files3-name := $(notdir $(input-files3))

# Work out what needs to be removed
oldheaders    := $(patsubst $(installdir)/%,%,$(wildcard $(installdir)/*.h))
unwanted      := $(filter-out $(all-files),$(oldheaders))

# Prefix unwanted with full paths to $(INSTALL_HDR_PATH)
unwanted-file := $(addprefix $(installdir)/, $(unwanted))

printdir = $(patsubst $(INSTALL_HDR_PATH)/%/,%,$(dir $@))

quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
                            file$(if $(word 2, $(all-files)),s))
      cmd_install = \
        $(CONFIG_SHELL) $< $(installdir) $(srcdir) $(input-files1-name); \
        $(CONFIG_SHELL) $< $(installdir) $(oldsrcdir) $(input-files2-name); \
        $(CONFIG_SHELL) $< $(installdir) $(gendir) $(input-files3-name); \
        for F in $(wrapper-files); do                                   \
                echo "\#include <asm-generic/$$F>" > $(installdir)/$$F;    \
        done;                                                           \
        touch $@

quiet_cmd_remove = REMOVE  $(unwanted)
      cmd_remove = rm -f $(unwanted-file)

quiet_cmd_check = CHECK   $(printdir) ($(words $(all-files)) files)
# Headers list can be pretty long, xargs helps to avoid
# the "Argument list too long" error.
      cmd_check = for f in $(all-files); do                          \
                  echo "$(installdir)/$${f}"; done                      \
                  | xargs                                            \
                  $(PERL) $< $(INSTALL_HDR_PATH)/include $(SRCARCH); \
	          touch $@

PHONY += __headersinst __headerscheck

ifndef HDRCHECK
# Rules for installing headers
__headersinst: $(subdirs) $(install-file)
	@:

targets += $(install-file)
$(install-file): scripts/headers_install.sh $(input-files1) $(input-files2) $(input-files3) FORCE
	$(if $(unwanted),$(call cmd,remove),)
	$(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
	$(call if_changed,install)

else
__headerscheck: $(subdirs) $(check-file)
	@:

targets += $(check-file)
$(check-file): scripts/headers_check.pl $(output-files) FORCE
	$(call if_changed,check)

endif

# Recursion
hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
.PHONY: $(subdirs)
$(subdirs):
	$(Q)$(MAKE) $(hdr-inst)=$(obj)/$@ dst=$(_dst)/$@

targets := $(wildcard $(sort $(targets)))
cmd_files := $(wildcard \
             $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))

ifneq ($(cmd_files),)
	include $(cmd_files)
endif

.PHONY: $(PHONY)
PHONY += FORCE
FORCE: ;
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