This requires a few changes since that dpcd value is above the
range currently cached by radeon. I've check the dp specs, and
above 0xf there's a big gap and nothing that looks like we should
cache it while a given device is plugged in. It's also the same value
that i915.ko uses.

Hence extend the various dpcd arrays in the radeon driver, use
proper symbolic constants where applicable (one place overallocated
the dpcd array to 25 bytes). Then also drop the rd_interval cache -
radeon_dp_link_train_init re-reads the dpcd block, so the values we'll
consume in train_cr and train_ce will always be fresh.

To avoid needless diff-churn, #define the old size of dpcd as the new
one and keep it around.

v2: Alex Deucher noticed one place where I've forgotten to replace 8
with DP_RECEIVER_CAP_SIZE.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Safe for the minor difference that the intel versions get an offset
into the link_status as an argument, both are the same again.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

radeon and intel use the exact same definition.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@gmail.com>

v2: Kill 2 more helpers in intel_dp.c that I've missed.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

radeon and intel use the exact same definition.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I want to move some dp link training helpers into this place, so in
the future this won't be just about i2c any longer.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the cached EDID from intel_dp and intel_lvds_connector to
intel_connector. Unify cached EDID handling for LVDS and eDP, in
preparation for adding more generic EDID caching later.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The caller, not intel_connector_update_modes(), should free the edid. This
improves the reusability of intel_connector_update_modes().
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pave the way for sharing some logic between eDP and LVDS.

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Create a generic struct intel_panel for sharing a data structure and code
between eDP and LVDS panels. Add the new struct to intel_connector so that
later on we can have generic EDID and mode reading functions with EDID
caching that transparently fallback to fixed mode when EDID is not
available.

Add intel_panel as a dummy first, and move data (such as the mentioned
fixed mode) to it in later patches.

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup tiny conflict in intel_dp_destroy.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since we do EDID caching in intel_dp_init, we can do the fixed mode
initialization there too. This should not change the functionality apart
from initializing fixed mode earlier. Particularly retain the behaviour of
only falling back to VBT if EDID is not available to not regress

commit 47f0eb22
Author: Keith Packard <keithp@keithp.com>
Date:   Mon Sep 19 14:33:26 2011 -0700

    drm/i915: Only use VBT panel mode on eDP if no EDID is found
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As there is 1:1 mapping between encoder and connector for the LVDS, the
goal is to simply reduce the amount of noise within the connector
functions, i.e. we split the encoder/connector for LVDS as best we can and
try to only operate on the LVDS connector from the connector funcs and the
LVDS encoder form the encoder funcs.

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Get rid of saved int_lvds_connector and int_edp_connector in
drm_i915_private.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Introduce a local structure to move LVDS specific information away from the
drm_i915_private and onto the LVDS connector.

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In preparation for introducing intel_lvds_connector to move some of the
LVDS specific storage away from drm_i915_private, first rename the encoder
to avoid potential confusion.

Based on earlier work by Chris Wilson <chris@chris-wilson.co.uk>

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Linux 3.7-rc2

Backmerge to solve two ugly conflicts:
- uapi. We've already added new ioctl definitions for -next. Do I need to say more?
- wc support gtt ptes. We've had to revert this for snb+ for 3.7 and
  also fix a few other things in the code. Now we know how to make it
  work on snb+, but to avoid losing the other fixes do the backmerge
  first before re-enabling wc gtt ptes on snb+.

And a few other minor things, among them git getting confused in
intel_dp.c and seemingly causing a conflict out of nothing ...

Conflicts:
	drivers/gpu/drm/i915/i915_reg.h
	drivers/gpu/drm/i915/intel_display.c
	drivers/gpu/drm/i915/intel_dp.c
	drivers/gpu/drm/i915/intel_modes.c
	include/drm/i915_drm.h
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull arm64 fixes from Catalin Marinas:
 "Main changes:
   - AArch64 Linux compilation fixes following 3.7-rc1 changes
     (MODULES_USE_ELF_RELA, update_vsyscall() prototype)
   - Unnecessary register setting in start_thread() (thanks to Al Viro)
   - ptrace fixes"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
  arm64: fix alignment padding in assembly code
  arm64: ptrace: use HW_BREAKPOINT_EMPTY type for disabled breakpoints
  arm64: ptrace: make structure padding explicit for debug registers
  arm64: No need to set the x0-x2 registers in start_thread()
  arm64: Ignore memory blocks below PHYS_OFFSET
  arm64: Fix the update_vsyscall() prototype
  arm64: Select MODULES_USE_ELF_RELA
  arm64: Remove duplicate inclusion of mmu_context.h in smp.c

An interesting effect of using the generic version of linkage.h
is that the padding is defined in terms of x86 NOPs, which can have
even more interesting effects when the assembly code looks like this:

ENTRY(func1)
	mov	x0, xzr
ENDPROC(func1)
	// fall through
ENTRY(func2)
	mov	x0, #1
	ret
ENDPROC(func2)

Admittedly, the code is not very nice. But having code from another
architecture doesn't look completely sane either.

The fix is to add arm64's version of linkage.h, which causes the insertion
of proper AArch64 NOPs.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The min/max call needed to have explicit types on some architectures
(e.g. mn10300). Use clamp_t instead to avoid the warning:

  kernel/sys.c: In function 'override_release':
  kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull perf fixes from Ingo Molnar:
 "Assorted small fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf python: Properly link with libtraceevent
  perf hists browser: Add back callchain folding symbol
  perf tools: Fix build on sparc.
  perf python: Link with libtraceevent
  perf python: Initialize 'page_size' variable
  tools lib traceevent: Fix missed freeing of subargs in free_arg() in filter
  lib tools traceevent: Add back pevent assignment in __pevent_parse_format()
  perf hists browser: Fix off-by-two bug on the first column
  perf tools: Remove warnings on JIT samples for srcline sort key
  perf tools: Fix segfault when using srcline sort key
  perf: Require exclude_guest to use PEBS - kernel side enforcement
  perf tool: Precise mode requires exclude_guest

Namhyung Kim reported that the build fails with:

  GEN python/perf.so
  gcc: error: python_ext_build/tmp//../../libtraceevent.a: No such file or directory
  error: command 'gcc' failed with exit status 1
  cp: cannot stat `python_ext_build/lib/perf.so': No such file or directory
  make: *** [python/perf.so] Error 1

We need to propagate the TE_PATH variable to the setup.py file.
Reported-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/n/tip-8umiPbm4sxpknKivbjgykhut@git.kernel.org
[ Fixed superfluous variable build error. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

* The python binding needs to link with libtraceevent and to initialize
  the 'page_size' variable so that mmaping works again.

* The callchain folding character that appears on the TUI just before
  the overhead had disappeared due to recent changes, add it back.

* Intel PEBS in VT-x context uses the DS address as a guest linear address,
  even though its programmed by the host as a host linear address. This either
  results in guest memory corruption and or the hardware faulting and 'crashing'
  the virtual machine.  Therefore we have to disable PEBS on VT-x enter and
  re-enable on VT-x exit, enforcing a strict exclude_guest.

  Kernel side enforcement fix by Peter Zijlstra, tooling side fix by David Ahern.

* Fix build on sparc due to UAPI, fix from David Miller.

* Fixes for the srclike sort key for unresolved symbols and when processing
  samples in JITted code, where we don't have an ELF file, just an special
  symbol table, fixes from Namhyung Kim.

* Fix some leaks in libtraceevent, from Steven Rostedt.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull ARM soc fixes from Olof Johansson:
 "A set of fixes and some minor cleanups for -rc2:

   - A series from Arnd that fixes warnings in drivers and other code
     included by ARM defconfigs.  Most have been acked by corresponding
     maintainers (and seem quite hard to argue not picking up anyway in
     the few exception cases).
   - A few misc patches from the list for integrator/vt8500/i.MX
   - A batch of fixes to OMAP platforms, fixing:
     - boot problems on beaglebone,
     - regression fixes for local timers
     - clockdomain locking fixes
     - a few boot/sparse warnings
   - For Tegra:
     - Clock rate calculation overflow fix
     - Revert a change that removed timer clocks and a fix for symbol
       name clashes
   - For Renesas:
     - IO accessor / annotation cleanups to remove warnings
   - For Kirkwood/Dove/mvebu:
     - Fixes for device trees for Dove (some minor cleanups, some fixes)
     - Fixes for the mvebu gpio driver
     - Fix build problem for Feroceon due to missing ifdefs
     - Fix lsxl DTS files"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  ARM: kirkwood: fix buttons on lsxl boards
  ARM: kirkwood: fix LEDs names for lsxl boards
  ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2
  gpio: mvebu: Add missing breaks in mvebu_gpio_irq_set_type
  ARM: dove: Add crypto engine to DT
  ARM: dove: Remove watchdog from DT
  ARM: dove: Restructure SoC device tree descriptor
  ARM: dove: Fix clock names of sata and gbe
  ARM: dove: Fix tauros2 device tree init
  ARM: dove: Add pcie clock support
  ARM: OMAP2+: Allow kernel to boot even if GPMC fails to reserve memory
  ARM: OMAP: clockdomain: Fix locking on _clkdm_clk_hwmod_enable / disable
  ARM: s3c: mark s3c2440_clk_add as __init_refok
  spi/s3c64xx: use correct dma_transfer_direction type
  ARM: OMAP4: devices: fixup OMAP4 DMIC platform device error message
  ARM: OMAP2+: clock data: Add dev-id for the omap-gpmc dummy fck
  ARM: OMAP: resolve sparse warning concerning debug_card_init()
  ARM: OMAP4: Fix twd_local_timer_register regression
  ARM: tegra: add tegra_timer clock
  ARM: tegra: rename tegra system timer
  ...

Emit the magic string that indicates a module has a signature after the
signature data instead of before it.  This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string.  Instead we just need to do a single memcmp().

This works because at the end of the signature data there is the
fixed-length signature information block.  This block then falls
immediately prior to the magic number.

From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

From Jason Cooper:
 - improve #ifdef logic to prevent linker errors with CACHE_FEROCEON_L2
 - lsxl board dts fixes

* tag 'kirkwood_fixes_for_v3.7' of git://git.infradead.org/users/jcooper/linux:
  ARM: kirkwood: fix buttons on lsxl boards
  ARM: kirkwood: fix LEDs names for lsxl boards
  ARM: Kirkwood: fix disabling CACHE_FEROCEON_L2

The module build process no longer creates intermediate files for module
signing, so remove them from .gitignore.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Turn sign-file into perl and merge in x509keyid.  The latter doesn't
need to be a separate script as it doesn't actually need to work out the
SHA1 sum of the X.509 certificate itself, since it can get that from the
X.509 certificate.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We were programming register 0x42020 twice on those platforms. Once
should be enough.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the consolidated registers, it appears that we're setting the same
bis several times. Let's just collect the bits we want to set and program
it once.

v2: More cleanup. Also program 0x42004 and 0x45000 for FBC on non
    mobile platforms (Paulo Zanoni)
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Undo the functional change as discussed on irc.]
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Merge branch 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes

A collection of warning fixes on non-ARM code from Arnd Bergmann:

* 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: s3c: mark s3c2440_clk_add as __init_refok
  spi/s3c64xx: use correct dma_transfer_direction type
  pcmcia: sharpsl: don't discard sharpsl_pcmcia_ops
  USB: EHCI: mark ehci_orion_conf_mbus_windows __devinit
  mm/slob: use min_t() to compare ARCH_SLAB_MINALIGN
  SCSI: ARM: make fas216_dumpinfo function conditional
  SCSI: ARM: ncr5380/oak uses no interrupts

  /proc/<pid>/numa_maps scans vma and show mempolicy under
  mmap_sem. It sometimes accesses task->mempolicy which can
  be freed without mmap_sem and numa_maps can show some
  garbage while scanning.

This patch tries to take reference count of task->mempolicy at reading
numa_maps before calling get_vma_policy(). By this, task->mempolicy
will not be freed until numa_maps reaches its end.

V2->v3
  -  updated comments to be more verbose.
  -  removed task_lock() in numa_maps code.
V1->V2
  -  access task->mempolicy only once and remember it.  Becase kernel/exit.c
     can overwrite it.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull miscellaneous x86 fixes from Peter Anvin:
 "The biggest ones are fixing suspend/resume breakage on 32 bits, and an
  interrim fix for mapping over holes that allows AMD kit with more than
  1 TB.

  A final solution for the latter is in the works, but involves some
  fairly invasive changes that will probably mean it will only be
  appropriate for 3.8."

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, MCE: Remove bios_cmci_threshold sysfs attribute
  x86, amd, mce: Avoid NULL pointer reference on CPU northbridge lookup
  x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
  x86/cache_info: Use ARRAY_SIZE() in amd_l3_attrs()
  x86/reboot: Remove quirk entry for SBC FITPC
  x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID

Merge misc fixes from Andrew Morton:
 "Seven fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (7 patches)
  lib/dma-debug.c: fix __hash_bucket_find()
  mm: compaction: correct the nr_strict va isolated check for CMA
  firmware/memmap: avoid type conflicts with the generic memmap_init()
  pidns: remove recursion from free_pid_ns()
  drivers/video/backlight/lm3639_bl.c: return proper error in lm3639_bled_mode_store() error paths
  kernel/sys.c: fix stack memory content leak via UNAME26
  linux/coredump.h needs asm/siginfo.h

If there is only one match, the unique matched entry should be returned.

Without the fix, the upcoming dma debug interfaces ("dma-debug: new
interfaces to debug dma mapping errors") can't work reliably because
only device and dma_addr are passed to dma_mapping_error().
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Reported-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: NShuah Khan <shuah.khan@hp.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Thierry reported that the "iron out" patch for isolate_freepages_block()
had problems due to the strict check being too strict with "mm:
compaction: Iron out isolate_freepages_block() and
isolate_freepages_range() -fix1".  It's possible that more pages than
necessary are isolated but the check still fails and I missed that this
fix was not picked up before RC1.  This same problem has been identified
in 3.7-RC1 by Tony Prisk and should be addressed by the following patch.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Tested-by: NTony Prisk <linux@prisktech.co.nz>
Reported-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NRik van Riel <riel@redhat.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Richard Davies <richard@arachsys.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this build error:

  drivers/firmware/memmap.c:240:19: error: conflicting types for 'memmap_init'
  arch/ia64/include/asm/pgtable.h:565:17: note: previous declaration of 'memmap_init' was here
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Bernhard Walle <bwalle@suse.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

free_pid_ns() operates in a recursive fashion:

free_pid_ns(parent)
  put_pid_ns(parent)
    kref_put(&ns->kref, free_pid_ns);
      free_pid_ns

thus if there was a huge nesting of namespaces the userspace may trigger
avalanche calling of free_pid_ns leading to kernel stack exhausting and a
panic eventually.

This patch turns the recursion into an iterative loop.

Based on a patch by Andrew Vagin.

[akpm@linux-foundation.org: export put_pid_ns() to modules]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>