The CRTC helper .commit() operation is legacy code, the atomic helpers
prefer the .enable() operation. Replace the .commit() helper operation
with .enable() in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-6-laurent.pinchart+renesas@ideasonboard.com

The CRTC .prepare() helper operation is part of the legacy helpers and
is deprecated in favour of the .disable() helper operation. As the
vmwgfx driver provides a .disable() helper operation, and as the
.prepare() helper operation implementation is empty, we can remove it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-5-laurent.pinchart+renesas@ideasonboard.com

The CRTC helper .commit() operation is legacy code, the atomic helpers
prefer the .enable() operation. Replace the .commit() helper operation
with .enable() in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-4-laurent.pinchart+renesas@ideasonboard.com

The CRTC .dpms() helper operation is called by the atomic helpers only
when no .prepare(), .atomic_disable() or .disable() operation is
provided. As the qxl driver provides a .disable() operation, the .dpms()
operation is unused and can be removed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-3-laurent.pinchart+renesas@ideasonboard.com

The CRTC helper .prepare() operation is legacy code, the atomic helpers
prefer the .disable() operation. As the arcpgu driver implements the
.disable() and .prepare() operations identicallly, .prepare() can be
removed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-2-laurent.pinchart+renesas@ideasonboard.com

The CRTC helper .commit() operation is legacy code, the atomic helpers
prefer the .enable() operation. As the arcpgu driver implements the
.enable() operation, .commit() is never used and can be removed.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170627211621.27767-1-laurent.pinchart+renesas@ideasonboard.com

There's no reason for drivers to call this, and all the ones I've
removed looked very fishy:
- Proper quiescenting of the vblank machinery should be done by
  calling drm_crtc_vblank_off(), which is best done by shutting down
  the entire display engine with drm_atomic_helper_shutdown.

- Releasing of allocated memory is done by the core already, it calls
  drm_vblank_cleanup as a fallback.

- drm_vblank_cleanup also has checks for drivers which forget to clean
  up vblank interrupts.

This essentially reverts

commit e77cef9c
Author: Jerome Glisse <jglisse@redhat.com>
Date:   Thu Jan 7 15:39:13 2010 +0100

    drm: Avoid calling vblank function is vblank wasn't initialized

which was done to fix a bug in radeon code with msi interrupts:

commit 003e69f9
Author: Jerome Glisse <jglisse@redhat.com>
Date:   Thu Jan 7 15:39:14 2010 +0100

    drm/radeon/kms: Don't try to enable IRQ if we have no handler installed

Afaict from digging around in old code, this was needed to avoid
blowing up in the ums fallback, and has stopped serving it's purpose
long ago - if irq init fails, the driver fails to load, and there's
really no way to blow up anymore.

Long story short, this was most likely a small ums compat/fallback
hack that became a thing of it's own and got cargo-cult duplicated all
over the drm codebase for essentially no gain at all.

v2: Mention that for drivers with a ->release callback cleanup is
handled by drm_dev_fini() (Thierry).

Cc: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170626161949.25629-2-daniel.vetter@ffwll.ch

This was accidentally restored in

commit de5cc815
Author: Liviu Dudau <Liviu.Dudau@arm.com>
Date:   Tue Jun 6 15:05:21 2017 +0100

    drm/arm: hdlcd: Set the CRTC's port before binding the encoder

Fixes: de5cc815 ("drm/arm: hdlcd: Set the CRTC's port before binding the encoder.")
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170628091141.14539-1-daniel.vetter@ffwll.ch

Problem : While running IGT kms_atomic_transition test suite i encountered
a hang in drmHandleEvent immediately following  an atomic_commit.
After dumping the atomic state I relized that in this case there was
not even one CRTC attached to the state and only disabled
planes. This probably due to a commit which hadn't changed any property
which would require attaching crtc state. This means drmHandleEvent
will never wake up from read since without CRTC in atomic state
the event fd will not be signaled.

Fix: Protect against this issue by failing atomic_commit early in
drm_mode_atomic_commit where such probelm can be identified.

v2:
Fix typos and extra newlines.

Change-Id: I3ee28ffae35fd1e8bfe553146c44da53da02e6f8
Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1497981426-27203-1-git-send-email-Andrey.Grodzovsky@amd.com

Required for Daniel's drm_vblank_cleanup cleanup

The crtc->commit_lock only protects commit_list and commit_entry. If
we chase the pointer from the drm_atomic_state update structure, then
we don't need any locks (since we hold a reference already).

Simplify the locking accordingly.

Noticed while reviewing a patch from Boris.

Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621091627.30837-1-daniel.vetter@ffwll.ch

Again stopping the vblank before uninstalling the irq handler is kinda
the wrong way round, but the fb_off stuff should take care of
disabling the dsiplay at least in most cases. So drop the
drm_vblank_cleanup code since it's not really doing anything, it looks
all cargo-culted.

v2: Appease gcc better.

v3: Simplify code (Sean Paul)

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170626161949.25629-1-daniel.vetter@ffwll.ch

Linux 4.12-rc7

Needed at least rc6 for drm-misc-next-fixes, may as well go to rc7

udl doesn't shut down the display, so stopping the vblank isn't going
to do much good either. Just drop it.

Cc: Dave Airlie <airlied@redhat.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-11-daniel.vetter@ffwll.ch

Either not relevant (in the load error paths) or done better already
(in the unload code, by calling drm_atomic_helper_shutdown). Drop it.

Cc: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-9-daniel.vetter@ffwll.ch

nouveau_display_vblank_fini is called in the load error path (where it
doesn't matter) and module unload (where vblanks have been shut down
correctly already through drm_vblank_off), we can drop it.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-8-daniel.vetter@ffwll.ch

Seems entirely cargo-culted.

Cc: CK Hu <ck.hu@mediatek.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-6-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-7-daniel.vetter@ffwll.ch

On the load error path we can't have pending vblank interrupts, and on
unload we already call drm_atomic_helper_shutdown beforehand! So all
good to nuke it.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-5-daniel.vetter@ffwll.ch

Again we probably want a drm_atomic_helper_shutdown somewhere, but
that's a bit more analysis.

Cc: Xinliang Liu <z.liuxinliang@hisilicon.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Chen Feng <puck.chen@hisilicon.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-4-daniel.vetter@ffwll.ch

So this seems to be the first driver that does it the right way round,
so fix it up by calling drm_atomic_helper_shutdown instead. We need to
do that before the last kms user is gone (fbdev emulation), but before
we start shutting down hw stuff like interrupts.

Cc: Xinliang Liu <z.liuxinliang@hisilicon.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Chen Feng <puck.chen@hisilicon.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170621082850.13224-3-daniel.vetter@ffwll.ch

Pull x86 fix from Thomas Gleixner:
 "A single fix to unbreak the vdso32 build for 64bit kernels caused by
  excess #includes in the mshyperv header"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mshyperv: Remove excess #includes from mshyperv.h

Pull timer fixes from Thomas Gleixner:
 "A few fixes for timekeeping and timers:

   - Plug a subtle race due to a missing READ_ONCE() in the timekeeping
     code where reloading of a pointer results in an inconsistent
     callback argument being supplied to the clocksource->read function.

   - Correct the CLOCK_MONOTONIC_RAW sub-nanosecond accounting in the
     time keeping core code, to prevent a possible discontuity.

   - Apply a similar fix to the arm64 vdso clock_gettime()
     implementation

   - Add missing includes to clocksource drivers, which relied on
     indirect includes which fails in certain configs.

   - Use the proper iomem pointer for read/iounmap in a probe function"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW
  time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
  time: Fix clock->read(clock) race around clocksource changes
  clocksource: Explicitly include linux/clocksource.h when needed
  clocksource/drivers/arm_arch_timer: Fix read and iounmap of incorrect variable

Pull perf fixes from Thomas Gleixner:
 "Three fixlets for perf:

   - Return the proper error code if aux buffers for a event are not
     supported.

   - Calculate the probe offset for inlined functions correctly

   - Update the Skylake DTLB load/store miss event so it can count 1G
     TLB entries as well"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf probe: Fix probe definition for inlined functions
  perf/x86/intel: Add 1G DTLB load/store miss support for SKL
  perf/aux: Correct return code of rb_alloc_aux() if !has_aux(ev)

Pull irq fix from Thomas Gleixner:
 "A single fix for the MIPS GIC to prevent ftrace recursion"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips-gic: Mark count and compare accessors notrace

Pull input fixes from Dmitry Torokhov:

 - a quirk to i8042 to ignore timeout bit on Lifebook AH544

 - a fixup to Synaptics RMI function 54 that was breaking some Dells

 - a fix for memory leak in soc_button_array driver

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: synaptics-rmi4 - only read the F54 query registers which are used
  Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list
  Input: soc_button_array - fix leaking the ACPI button descriptor buffer

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are the target-pending fixes for v4.12-rc7 that have been queued
  up for the last 2 weeks. This includes:

   - Fix a TMR related kref underflow detected by the recent refcount_t
     conversion in upstream.

   - Fix a iscsi-target corner case during explicit connection logout
     timeout failure.

   - Address last fallout in iscsi-target immediate data handling from
     v4.4 target-core now allowing control CDB payload underflow"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: Reject immediate data underflow larger than SCSI transfer length
  iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP
  target: Fix kref->refcount underflow in transport_cmd_finish_abort

Merge tag 'kbuild-fixes-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:
 "Nothing scary, just some random fixes:

   - fix warnings of host programs

   - fix "make tags" when COMPILED_SOURCE=1 is specified along with O=

   - clarify help message of C=1 option

   - fix dependency for ncurses compatibility check

   - fix "make headers_install" for fakechroot environment"

* tag 'kbuild-fixes-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix sparse warnings in nconfig
  kbuild: fix header installation under fakechroot environment
  kconfig: Check for libncurses before menuconfig
  Kbuild: tiny correction on `make help`
  tags: honor COMPILED_SOURCE with apart output directory
  genksyms: add printf format attribute to error_with_pos()

Pull timer fix from Eric Biederman:
 "This fixes an issue of confusing injected signals with the signals
  from posix timers that has existed since posix timers have been in the
  kernel.

  This patch is slightly simpler than my earlier version of this patch
  as I discovered in testing that I had misspelled "#ifdef
  CONFIG_POSIX_TIMERS". So I deleted that unnecessary test and made
  setting of resched_timer uncondtional.

  I have tested this and verified that without this patch there is a
  nasty hang that is easy to trigger, and with this patch everything
  works properly"

Thomas Gleixner dixit:
 "It fixes the problem at hand and covers the ptrace case as well, which
  I missed.

  Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Only reschedule timers on signals timers have sent

A recent commit included linux/slab.h in linux/irq.h. This breaks the build
of vdso32 on a 64-bit kernel.

The reason is that linux/irq.h gets included into the vdso code via
linux/interrupt.h which is included from asm/mshyperv.h. That makes the
32-bit vdso compile fail, because slab.h includes the pgtable headers for
64-bit on a 64-bit build.

Neither linux/clocksource.h nor linux/interrupt.h are needed in the
mshyperv.h header file itself - it has a dependency on <linux/atomic.h>.

Remove the includes and unbreak the build.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: devel@linuxdriverproject.org
Fixes: dee863b5 ("hv: export current Hyper-V clocksource")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1706231038460.2647@nanosSigned-off-by: Ingo Molnar <mingo@kernel.org>

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 4.12. Most of these actually came in last
  week but got held up for some more testing.

   - three fixes for kprobes/ftrace/livepatch interactions.

   - properly handle data breakpoints when using the Radix MMU.

   - fix for perf sampling of registers during call_usermodehelper().

   - properly initialise the thread_info on our emergency stacks

   - add an explicit flush when doing TLB invalidations for a process
     using NPU2.

  Thanks to: Alistair Popple, Naveen N. Rao, Nicholas Piggin, Ravi
  Bangoria, Masami Hiramatsu"

* tag 'powerpc-4.12-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64: Initialise thread_info for emergency stacks
  powerpc/powernv/npu-dma: Add explicit flush when sending an ATSD
  powerpc/perf: Fix oops when kthread execs user process
  powerpc/64s: Handle data breakpoints in Radix mode
  powerpc/kprobes: Skip livepatch_handler() for jprobes
  powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS
  powerpc/kprobes: Pause function_graph tracing during jprobes handling

Pull ACPI fix from Rafael Wysocki:
 "This fixes the ACPI-based enumeration of some I2C and SPI devices
  broken in 4.11.

  Specifics:

   - I2C and SPI devices are expected to be enumerated by the I2C and
     SPI subsystems, respectively, but due to a change made during the
     4.11 cycle, in some cases the ACPI core marks them as already
     enumerated which causes the I2C and SPI subsystems to overlook
     them, so fix that (Jarkko Nikula)"

* tag 'acpi-4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / scan: Fix enumeration for special SPI and I2C devices

Pull i2c fix from Wolfram Sang.

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: imx: Use correct function to write to register

Pull GPIO fix from Linus Walleij:
 "A single GPIO patch fixing the compatible string for the MVEBU PWM
  controller embedded in the GPIO controller before we release v4.12.
  Hopefully"

* tag 'gpio-v4.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mvebu: change compatible string for PWM support

Pull sound fixes from Takashi Iwai:
 "Nothing exciting here, just a few stable fixes:

   - suppress spurious kernel WARNING in PCM core

   - fix potential spin deadlock at error handling in firewire

   - HD-audio PCI ID addition / fixup"

* tag 'sound-4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Apply quirks to Broxton-T, too
  ALSA: firewire-lib: Fix stall of process context at packet error
  ALSA: pcm: Don't treat NULL chmap as a fatal error
  ALSA: hda - Add Coffelake PCI ID

Pull drm fixes from Dave Airlie:
 "A varied bunch of fixes, one for an API regression with connectors.

  Otherwise amdgpu and i915 have a bunch of varied fixes, the shrinker
  ones being the most important"

* tag 'drm-fixes-for-v4.12-rc7' of git://people.freedesktop.org/~airlied/linux:
  drm: Fix GETCONNECTOR regression
  drm/radeon: add a quirk for Toshiba Satellite L20-183
  drm/radeon: add a PX quirk for another K53TK variant
  drm/amdgpu: adjust default display clock
  drm/amdgpu/atom: fix ps allocation size for EnableDispPowerGating
  drm/amdgpu: add Polaris12 DID
  drm/i915: Don't enable backlight at setup time.
  drm/i915: Plumb the correct acquire ctx into intel_crtc_disable_noatomic()
  drm/i915: Fix deadlock witha the pipe A quirk during resume
  drm/i915: Remove __GFP_NORETRY from our buffer allocator
  drm/i915: Encourage our shrinker more when our shmemfs allocations fails
  drm/i915: Differentiate between sw write location into ring and last hw read

Pull random fixes from Ted Ts'o:
 "Fix some locking and gcc optimization issues from the most recent
  random_for_linus_stable pull request"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: silence compiler warnings and fix race

Merge tag 'for-4.12/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a revert of a DM mirror commit that has proven to make the code prone
   to crash

 - a DM io reference count fix that resolves a NULL pointer seen when
   issuing discards to a DM mirror target's device whose mirror legs do
   not all support discards

 - a couple DM integrity fixes

* tag 'for-4.12/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm io: fix duplicate bio completion due to missing ref count
  dm integrity: fix to not disable/enable interrupts from interrupt context
  Revert "dm mirror: use all available legs on multiple failures"
  dm integrity: reject mappings too large for device

Merge misc fixes from Andrew Morton:
 "8 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  fs/exec.c: account for argv/envp pointers
  ocfs2: fix deadlock caused by recursive locking in xattr
  slub: make sysfs file removal asynchronous
  lib/cmdline.c: fix get_options() overflow while parsing ranges
  fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
  autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL
  mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge vmap mappings
  mm, thp: remove cond_resched from __collapse_huge_page_copy

When limiting the argv/envp strings during exec to 1/4 of the stack limit,
the storage of the pointers to the strings was not included.  This means
that an exec with huge numbers of tiny strings could eat 1/4 of the stack
limit in strings and then additional space would be later used by the
pointers to the strings.

For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721
single-byte strings would consume less than 2MB of stack, the max (8MB /
4) amount allowed, but the pointers to the strings would consume the
remaining additional stack space (1677721 * 4 == 6710884).

The result (1677721 + 6710884 == 8388605) would exhaust stack space
entirely.  Controlling this stack exhaustion could result in
pathological behavior in setuid binaries (CVE-2017-1000365).

[akpm@linux-foundation.org: additional commenting from Kees]
Fixes: b6a2fea3 ("mm: variable length argument support")
Link: http://lkml.kernel.org/r/20170622001720.GA32173@beastSigned-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>