commit f03574f2d5b2d6229dcdf2d322848065f72953c7 upstream.

This code was an optimization for 32-bit NUMA systems.

It has probably been the cause of a number of subtle bugs over
the years, although the conditions to excite them would have
been hard to trigger.  Essentially, we remap part of the kernel
linear mapping area, and then sometimes part of that area gets
freed back in to the bootmem allocator.  If those pages get
used by kernel data structures (say mem_map[] or a dentry),
there's no big deal.  But, if anyone ever tried to use the
linear mapping for these pages _and_ cared about their physical
address, bad things happen.

For instance, say you passed __GFP_ZERO to the page allocator
and then happened to get handed one of these pages, it zero the
remapped page, but it would make a pte to the _old_ page.
There are probably a hundred other ways that it could screw
with things.

We don't need to hang on to performance optimizations for
these old boxes any more.  All my 32-bit NUMA systems are long
dead and buried, and I probably had access to more than most
people.

This code is causing real things to break today:

	https://lkml.org/lkml/2013/1/9/376

I looked in to actually fixing this, but it requires surgery
to way too much brittle code, as well as stuff like
per_cpu_ptr_to_phys().

[ hpa: Cc: this for -stable, since it is a memory corruption issue.
  However, an alternative is to simply mark NUMA as depends BROKEN
  rather than EXPERIMENTAL in the X86_32 subclause... ]

Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It turns out that there are more cases than CONFIG_DEBUG_PAGEALLOC that
can have holes in the kernel address space: it seems to happen easily
with Xen, and it looks like the AMD gart64 code will also punch holes
dynamically.

Actually hitting that case is still very unlikely, so just do the
access, and take an exception and fix it up for the very unlikely case
of it being a page-crosser with no next page.

And hey, this abstraction might even help other architectures that have
other issues with unaligned word accesses than the possible missing next
page.  IOW, this could do the byte order magic too.

Peter Anvin fixed a thinko in the shifting for the exception case.

Reported-and-tested-by: Jana Saout <jana@saout.de>
Cc:  Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
  ...

Pull more ARM updates from Russell King.

This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups.  They
all looked pretty trivial, though.

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
  ARM: fix Kconfig warning for HAVE_BPF_JIT
  ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
  ARM: 7349/1: integrator: convert to sparse irqs
  ARM: 7259/3: net: JIT compiler for packet filters
  ARM: 7334/1: add jump label support
  ARM: 7333/2: jump label: detect %c support for ARM
  ARM: 7338/1: add support for early console output via semihosting
  ARM: use set_current_blocked() and block_sigmask()
  ARM: exec: remove redundant set_fs(USER_DS)
  ARM: 7332/1: extract out code patch function from kprobes
  ARM: 7331/1: extract out insn generation code from ftrace
  ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
  ARM: 7351/1: ftrace: remove useless memory checks
  ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
  ARM: Versatile Express: add NO_IOPORT
  ARM: get rid of asm/irq.h in asm/prom.h
  ARM: 7319/1: Print debug info for SIGBUS in user faults
  ARM: 7318/1: gic: refactor irq_start assignment
  ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
  ARM: 7315/1: perf: add support for the Cortex-A7 PMU
  ...

Pull arch/tile (really asm-generic) update from Chris Metcalf:
 "These are a couple of asm-generic changes that apply to tile."

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  compat: use sys_sendfile64() implementation for sendfile syscall
  [PATCH v3] ipc: provide generic compat versions of IPC syscalls

Pull x86 platform driver updates from Matthew Garrett:
 "Some significant updates to samsung-laptop, additional hardware
  support for Toshibas, misc updates to various hardware and a new
  backlight driver for some Apple machines."

Fix up trivial conflicts: geode Geos update happening next to net5501
support, and MSIC thermal platform support added twice.

* 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86: (77 commits)
  acer-wmi: add quirk table for video backlight vendor mode
  drivers/platform/x86/amilo-rfkill.c::amilo_rfkill_probe() avoid NULL deref
  samsung-laptop: unregister ACPI video module for some well known laptops
  acer-wmi: No wifi rfkill on Sony machines
  thinkpad-acpi: recognize Lenovo as version string in newer V-series BIOS
  asus-wmi: don't update power and brightness when using scalar
  eeepc-wmi: split et2012 specific hacks
  eeepc-wmi: refine quirks handling
  asus-nb-wmi: set panel_power correctly
  asus-wmi: move WAPF variable into quirks_entry
  asus-wmi: store backlight power status for AIO machine
  asus-wmi: add scalar board brightness adj. support
  samsung-laptop: cleanup return type: mode_t vs umode_t
  drivers, samsung-laptop: fix usage of isalnum
  drivers, samsung-laptop: fix initialization of sabi_data in sabi_set_commandb
  asus-wmi: on/off bit is not set when reading the value
  eeepc-wmi: add extra keymaps for EP121
  asus-nb-wmi: ignore useless keys
  acer-wmi: support Lenovo ideapad S205 Brazos wifi switch
  acer-wmi: fix out of input parameter size when set
  ...

Pull x86 platform changes from Ingo Molnar.

Removes the Moorestown platform that nobody ever used.

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform: Move APIC ID validity check into platform APIC code
  x86/olpc/xo15/sci: Enable lid close wakeup control
  x86/geode/net5501: Add platform driver for Soekris Engineering net5501
  x86/geode/alix2: Supplement driver to include GPIO button support
  x86/mid/powerbtn: Use MSIC read/write instead of ipc_scu
  x86/mid/thermal: Turn off thermistor
  x86/mid/thermal: Add msic_thermal alias
  x86/mid/thermal: Convert to use Intel MSIC API
  x86/mid/scu_ipc: Remove Moorestown support
  x86/mid: Kill off Moorestown
  x86/mrst: Add msic_thermal platform support
  x86/config: Select MSIC MFD driver on Intel Medfield platform
  x86/mid: Remove Intel Moorestown
  x86/mrst: Set ISA bus type for fake MP IRQs
  x86/ioapic: Use legacy_pic to set correct gsi-irq mapping

Pull irq_domain support for all architectures from Grant Likely:
 "Generialize powerpc's irq_host as irq_domain

  This branch takes the PowerPC irq_host infrastructure (reverse mapping
  from Linux IRQ numbers to hardware irq numbering), generalizes it,
  renames it to irq_domain, and makes it available to all architectures.

  Originally the plan has been to create an all-new irq_domain
  implementation which addresses some of the powerpc shortcomings such
  as not handling 1:1 mappings well, but doing that proved to be far
  more difficult and invasive than generalizing the working code and
  refactoring it in-place.  So, this branch rips out the 'new'
  irq_domain and replaces it with the modified powerpc version (in a
  fully bisectable way of course).  It converts all users over to the
  new API and makes irq_domain selectable on any architecture.

  No architecture is forced to enable irq_domain, but the infrastructure
  is required for doing OpenFirmware style irq translations.  It will
  even work on SPARC even though SPARC has it's own mechanism for
  translating irqs at boot time.  MIPS, microblaze, embedded x86 and c6x
  are converted too.

  The resulting irq_domain code is probably still too verbose and can be
  optimized more, but that can be done incrementally and is a task for
  follow-on patches."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6: (31 commits)
  dt: fix twl4030 for non-dt compile on x86
  mfd: twl-core: Add IRQ_DOMAIN dependency
  devicetree: Add empty of_platform_populate() for !CONFIG_OF_ADDRESS (sparc)
  irq_domain: Centralize definition of irq_dispose_mapping()
  irq_domain/mips: Allow irq_domain on MIPS
  irq_domain/x86: Convert x86 (embedded) to use common irq_domain
  ppc-6xx: fix build failure in flipper-pic.c and hlwd-pic.c
  irq_domain/microblaze: Convert microblaze to use irq_domains
  irq_domain/powerpc: Replace custom xlate functions with library functions
  irq_domain/powerpc: constify irq_domain_ops
  irq_domain/c6x: Use library of xlate functions
  irq_domain/c6x: constify irq_domain structures
  irq_domain/c6x: Convert c6x to use generic irq_domain support.
  irq_domain: constify irq_domain_ops
  irq_domain: Create common xlate functions that device drivers can use
  irq_domain: Remove irq_domain_add_simple()
  irq_domain: Remove 'new' irq_domain in favour of the ppc one
  mfd: twl-core.c: Fix the number of interrupts managed by twl4030
  of/address: add empty static inlines for !CONFIG_OF
  irq_domain: Add support for base irq and hwirq in legacy mappings
  ...

Pull driver core patches for 3.4-rc1 from Greg KH:
 "Here's the big driver core merge for 3.4-rc1.

  Lots of various things here, sysfs fixes/tweaks (with the nlink
  breakage reverted), dynamic debugging updates, w1 drivers, hyperv
  driver updates, and a variety of other bits and pieces, full
  information in the shortlog."

* tag 'driver-core-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (78 commits)
  Tools: hv: Support enumeration from all the pools
  Tools: hv: Fully support the new KVP verbs in the user level daemon
  Drivers: hv: Support the newly introduced KVP messages in the driver
  Drivers: hv: Add new message types to enhance KVP
  regulator: Support driver probe deferral
  Revert "sysfs: Kill nlink counting."
  uevent: send events in correct order according to seqnum (v3)
  driver core: minor comment formatting cleanups
  driver core: move the deferred probe pointer into the private area
  drivercore: Add driver probe deferral mechanism
  DS2781 Maxim Stand-Alone Fuel Gauge battery and w1 slave drivers
  w1_bq27000: Only one thread can access the bq27000 at a time.
  w1_bq27000 - remove w1_bq27000_write
  w1_bq27000: remove unnecessary NULL test.
  sysfs: Fix memory leak in sysfs_sd_setsecdata().
  intel_idle: Revert change of auto_demotion_disable_flags for Nehalem
  w1: Fix w1_bq27000
  driver-core: documentation: fix up Greg's email address
  powernow-k6: Really enable auto-loading
  powernow-k7: Fix CPU family number
  ...

Trivial platform driver for Traverse Technologies Geos and Geos2
single-board computers. Uses SMBIOS to identify platform.
Based on progressive revisions of the leds-net5501 driver that
was rewritten by Ed Wildgoose as a platform driver.

Supports GPIO-based LEDs (3) and 1 polled button which is
typically used for a soft reset.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Reviewed-by: Ed Wildgoose <ed@wildgooses.com>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>