ktime_add_ns() may overflow on 32bit architectures

I've triggered an overflow when using ktime_add_ns() on a 32bit
architecture not supporting CONFIG_KTIME_SCALAR.

When passing a very high value for u64 nsec, e.g.  7881299347898368000 the
do_div() function converts this value to seconds (7881299347) which is
still to high to pass to the ktime_set() function as long.  The result in
my case is a negative value.

The problem on my system occurs in the tick-sched.c,
tick_nohz_stop_sched_tick() when time_delta is set to
timekeeping_max_deferment().  The check for time_delta < KTIME_MAX is
valid, thus ktime_add_ns() is called with a too large value resulting in a
negative expire value.  This leads to an endless loop in the ticker code:

time_delta: 7881299347898368000
expires = ktime_add_ns(last_update, time_delta)
expires: negative value

This error doesn't occurs on 64bit or architectures supporting
CONFIG_KTIME_SCALAR (e.g.  ARM, x86-32).  64-bit arches doesn't run into
this problem because ktime_add_ns() can directly calculate the result
without calling do_div() and ktime_set().

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

selftests: add basic posix timers selftests

Add some initial basic tests on a few posix timers interface such as
setitimer() and timer_settime().

These simply check that expiration happens in a reasonable timeframe after
expected elapsed clock time (user time, user + system time, real time,
...).

This is helpful for finding basic breakages while hacking
on this subsystem.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

posix_cpu_timers: consolidate expired timers check

Consolidate the common code amongst per thread and per process timers list
on tick time.

List traversal, expiry check and subsequent updates can be shared in a
common helper.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

posix_cpu_timers: consolidate timer list cleanups

Cleaning up the posix cpu timers on task exit shares some common code
among timer list types, most notably the list traversal and expiry time
update.

Unify this in a common helper.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

posix_cpu_timer: consolidate expiry time type

The posix cpu timer expiry time is stored in a union of two types: a 64
bits field if we rely on scheduler precise accounting, or a cputime_t if
we rely on jiffies.

This results in quite some duplicate code and special cases to handle the
two types.

Just unify this into a single 64 bits field.  cputime_t can always fit
into it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_list-convert-timer-list-to-be-a-proper-seq_file-v3-fix

fix comment typos, per Stephen

Cc: Dave Jones <davej@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_list-convert-timer-list-to-be-a-proper-seq_file-v3

v3: Corrected the case where max_cpus != nr_cpu_ids by exiting early.

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_list: convert timer list to be a proper seq_file

When running with 4096 cores attemping to read /proc/timer_list will fail
with an ENOMEM condition.  On a sufficantly large systems the total amount
of data is more then 4mb, so it won't fit into a single buffer.  The
failure can also occur on smaller systems when memory fragmentation is
high as reported by Dave Jones.

Convert /proc/timer_list to a proper seq_file with its own iterator.  This
is a little more complex given that we have to make two passes with two
separate headers.

[akpm@linux-foundation.org: whitespace fixlet]
[akpm@linux-foundation.org: fix up comment]
[akpm@linux-foundation.org: fix gcc warnings]
[akpm@linux-foundation.org: fix typo in comment]
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_list-split-timer_list_show_tickdevices-v4

v4: correct extra whitespace

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Dave Jones <davej@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

timer_list: split timer_list_show_tickdevices()

Split timer_list_show_tickdevices() out the header and just pull the rest up
to timer_list_show.  Also tweak the location of the whitespace.  This is all
to prep for the fix.

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

cyber2000fb: avoid palette corruption at higher clocks

When 1280x1024@75Hz mode is set, console palette is not set properly -
sometimes the background is white, sometimes yellow and text colors are
also messed up.  This does not happen at 1280x1024@60Hz and below.

It seems that the HW needs some time before setting the palette - maybe
the PLL needs more time to lock at higher speeds.  This patch fixes the
problem but without knowing what register to check for PLL lock(?), the
delay might be excessive.

On Fri, 28 Jan 2011 18:15:37 +0000
Russell King <rmk@arm.linux.org.uk> wrote:

> On Tue, Jan 18, 2011 at 01:14:24PM -0800, Andrew Morton wrote:
> > Russell, I have an (old) note here that this is awaiting an ack from
> > yourself?
>
> Well, I can reproduce this problem on the Netwinders here.  I'm not sure
> that we should delay all mode switches by one second - and any attempt
> to reduce this value does result in the palette not being set correctly.
>
> For 1280x1024-75, the dotclock is 135MHz, which gives a PLL values of
> 0x41 and 0x06.  That's: M=0x41+1, N=0x06+1, P=0x00 (top 2 bits of 0x06)
> -> Q=1
>
>  Fpll = 14.31818MHz * M / N
>  Fout = Fpll / Q
>
> The PLL itself is formed by dividing the 14-ish MHz frequency by N and
> phase comparing the output of the VCO, divided by M, and adjusting the
> VCO until the two correlate.  As VCOs typically tend to have a limited
> range, it's normal to divide the output frequency to produce a greater
> range - and in this case that's done by Q.
>
> For the 800x600-100 copied from /etc/fb.modes, this has a dotclock of
> 67.5MHz, which is exactly half this rate.  The PLL values for this are:
> M=0x41+1, N=0x06+1, P=0x01, giving PLL values of 0x41 and 0x46.
>
> Booting with 800x600-100 does not suffer the problem.  So it's not
> related to PLL lock time.  There's something else going on.
>
> Another experiment I tried was forcing the PLL values to produce 108MHz
> instead of 135MHz.  108MHz is the dotclock for 1280x1024-60.  This too
> doesn't suffer the problem.
>
> I've also tried chosing other delay values.  100ms is too short and
> produces the problem, but 1s works.  1s for a PLL to lock is a hell of
> a time, especially for a PLL operating in the MHz range.
>
> I've tried setting the PLL to a known good freqency, and then switching
> to 135MHz - the problem persists.  It's not like 135MHz is reaching the
> limits - it'll go up to 206MHz.
>
> So, I don't think this has anything to do with PLL locking.  I think
> there's something else going on which isn't immediately obvious - maybe
> bandwidth starvation preventing us from writing properly to the palette?
> As it's a horrible VGA, where you write the same register multiple times
> I wouldn't be surprised if some writes were going missing.
>
> I'll see if I can play around with it some more this evening, but I've
> spent an awful long time on just this issue already this afternoon...
>
> I think further investigation needs to happen on this patch before it's
> acceptable.  Or maybe we should prevent the cyberpro coming up in

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/mmp: remove legacy hw definitions

Removed legacy hw definitions in hw/mmp_ctrl.h.  These definitions are for
earlier soc versions and are not supported in this driver.

Signed-off-by: Zhou Zhu <zzhu3@marvell.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Lisa Du <cldu@marvell.com>
Cc: Guoqing Li <ligq@marvell.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/ep93xx-fb.c: fix section mismatch and use module_platform_driver

Remove the __init tags from the ep93xxfb_calc_fbsize() and
ep93xxfb_alloc_videomem() functions to fix the section mismatch warnings.

Use module_platform_driver() to remove the init/exit boilerplate.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/exynos/exynos_mipi_dsi.c: convert to devm_ioremap_resource()

Use the newly introduced devm_ioremap_resource() instead of
devm_request_and_ioremap() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages; so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Donghwa Lee <dh09.lee@samsung.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

video: fix a type warning in hyperv_fb.c

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver

This is the driver for the Hyper-V Synthetic Video, which supports screen
resolution up to Full HD 1920x1080 on Windows Server 2012 host, and
1600x1200 on Windows Server 2008 R2 or earlier.  It also solves the double
mouse cursor issue of the emulated video mode.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/video/console/fbcon_cw.c: fix compiler warning in cw_update_attr

with make W=1

saw

drivers/video/console/fbcon_cw.c: In function `cw_update_attr':
drivers/video/console/fbcon_cw.c:30:8: warning: variable `t' set but not used [-Wunused-but-set-variable]

fixed by removing as since its used nowhere

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

matroxfb: convert struct i2c_msg initialization to C99 format

Convert the struct i2c_msg initialization to C99 format.  This makes
maintaining and editing the code simpler.  Also helps once other fields
like transferred are added in future.

Thanks to Julia Lawall for automating the conversion.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Julia Lawall <julia@diku.dk>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drm/fb-helper: don't sleep for screen unblank when an oops is in progress

Otherwise the system will burn even brighter and worse, leave the user
wondering what's going on exactly.

Since we already have a panic handler which will (try) to restore the
entire fbdev console mode, we can just bail out.  Inspired by a patch from
Konstantin Khlebnikov.  The callchain leading to this, cut&pasted from
Konstantin's original patch:

callstack:
panic()
bust_spinlocks(1)
unblank_screen()
vc->vc_sw->con_blank()
fbcon_blank()
fb_blank()
info->fbops->fb_blank()
drm_fb_helper_blank()
drm_fb_helper_dpms()
drm_modeset_lock_all()
mutex_lock(&dev->mode_config.mutex)

Note that the entire locking in the fb helper around panic/sysrq and kdbg
is ...  non-existant.  So we have a decent change of blowing up
everything.  But since reworking this ties in with funny concepts like the
fbdev notifier chain or the impressive things which happen around
console_lock while oopsing, I'll leave that as an exercise for braver
souls than me.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Airlie <airlied@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: use vm_unmapped_area() on powerpc architecture

Update the powerpc slice_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Tested-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: remove free_area_cache use in powerpc architecture

As all other architectures have been converted to use vm_unmapped_area(),
we are about to retire the free_area_cache.

This change simply removes the use of that cache in
slice_get_unmapped_area(), which will most certainly have a
performance cost. Next one will convert that function to use the
vm_unmapped_area() infrastructure and regain the performance.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86: make 'mem=' option to work for efi platform

Current mem boot option only can work for non efi environment.  If the
user specifies add_efi_memmap, it cannot work for efi environment.  In the
efi environment, we call e820_add_region() to add the memory map.  So we
can modify __e820_add_region() and the mem boot option can work for efi
environment.

Note: Only E820_RAM is limited, and BOOT_SERVICES_{CODE,DATA} are always
mapped(If its address >= mem_limit, the memory won't be freed in
efi_free_boot_services()).

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yasuaki ISIMATU <isimatu.yasuaki@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

sound: convert snd_info_register() to use proc_create_data()

Convert snd_info_register to use proc_create_data instead of
create_proc_entry.  This corrects a sparse warning introduced by "procfs:
Improve Scaling in proc" It is also a bit cleaner to let proc_create_data
set the ->data and ->proc_fops.

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/mm/init_64.c: fix build warning when CONFIG_MEMORY_HOTREMOVE=n

There is a warning while building kernel with
CONFIG_MEMORY_HOTPLUG=y && CONFIG_MEMORY_HOTREMOVE=n:
arch/x86/mm/init_64.c:1024: warning:kernel_physical_mapping_remove defined but not used

So move kernel_physical_mapping_remove() into "#ifdef
CONFIG_MEMORY_HOTREMOVE" block

Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Liujiang <jiang.liu@huawei.com>
Cc: qiuxishi <qiuxishi@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kthread: kill task_get_live_kthread()

task_get_live_kthread() looks confusing and unneeded.  It does
get_task_struct() but only kthread_stop() needs this, it can be called
even if the calller doesn't have a reference when we know that this
kthread can't exit until we do kthread_stop().

kthread_park() and kthread_unpark() do not need get_task_struct(), the
callers already have the reference.  And it can not help if we can race
with the exiting kthread anyway, kthread_park() can hang forever in this
case.

Change kthread_park() and kthread_unpark() to use to_live_kthread(),
change kthread_stop() to do get_task_struct() by hand and remove
task_get_live_kthread().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kthread: introduce to_live_kthread()

"k->vfork_done != NULL" with a barrier() after to_kthread(k) in
task_get_live_kthread(k) looks unclear, and sub-optimal because we load
->vfork_done twice.

All we need is to ensure that we do not return to_kthread(NULL).  Add a
new trivial helper which loads/checks ->vfork_done once, this also looks
more understandable.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/char/random.c: fix priming of last_data

Commit ec8f02da9e ("random: prime last_data value per fips requirements")
added priming of last_data per fips requirements.  Unfortuantely, it did
so in a way that can lead to multiple threads all incrementing nbytes, but
only one actually doing anything with the extra data, which leads to some
fun random corruption and panics.

The fix is to simply do everything needed to prime last_data in a single
shot, so there's no window for multiple cpus to increment nbytes -- in
fact, we won't even increment or decrement nbytes anymore, we'll just
extract the needed EXTRACT_SIZE one time per pool and then carry on with
the normal routine.

All these changes have been tested across multiple hosts and architectures
where panics were previously encoutered.  The code changes are are
strictly limited to areas only touched when when booted in fips mode.

This change should also go into 3.8-stable, to make the myriads of fips
users on 3.8.x happy.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Jan Stodola <jstodola@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mips: define KVM_USER_MEM_SLOTS

ARCH=mips, config=fuloong2e_defconfig:

akpm3:/usr/src/25> make arch/mips/kernel/early_printk.o
...
CC      arch/mips/kernel/asm-offsets.s
In file included from arch/mips/kernel/asm-offsets.c:20:
include/linux/kvm_host.h:334: error: `KVM_USER_MEM_SLOTS' undeclared here (not in a function)

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

thinkpad-acpi: kill hotkey_thread_mutex

hotkey_kthread() does try_to_freeze() under hotkey_thread_mutex.

We can simply kill this mutex, hotkey_poll_stop_sync() does not need to
serialize with hotkey_kthread().  When kthread_stop() returns the thread
is already dead, it called do_exit()->complete_vfork_done().

Reported-by: Artem Savkov <artem.savkov@gmail.com>
Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

revert "ipc: don't allocate a copy larger than max"

Revert 88b9e456b164.  Dave has confirmed that this was causing oopses
during trinity testing.

Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: export split_page()

This symbol will be used in the Hyper-V balloon driver to support 2M
allocations.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Merge remote-tracking branch 'lzo-update/lzo-update'

Merge remote-tracking branch 'clk/clk-next'

Merge remote-tracking branch 'signal/for-next'

Conflicts:
arch/mips/kernel/linux32.c
arch/tile/Kconfig
arch/tile/kernel/compat.c
fs/splice.c
include/asm-generic/unistd.h

Merge remote-tracking branch 'userns/for-next'

Merge remote-tracking branch 'pwm/for-next'

Merge remote-tracking branch 'tegra/for-next'

Conflicts:
arch/arm/mach-tegra/tegra.c
drivers/clocksource/tegra20_timer.c

Merge remote-tracking branch 'samsung/for-next'

Merge remote-tracking branch 'renesas/next'

Merge remote-tracking branch 'msm/for-next'

Merge remote-tracking branch 'imx-mxs/for-next'

Conflicts:
arch/arm/Kconfig.debug
drivers/clocksource/Makefile

Merge remote-tracking branch 'ep93xx/ep93xx-for-next'

Merge remote-tracking branch 'bcm2835/for-next'

Conflicts:
arch/arm/Kconfig
arch/arm/Kconfig.debug

Merge remote-tracking branch 'arm-soc/for-next'

Merge remote-tracking branch 'mailbox/dbx500-prcmu-mailbox'

Merge remote-tracking branch 'gen-gpio/for_next'

Conflicts:
arch/sh/kernel/cpu/sh2a/Makefile

Merge remote-tracking branch 'gpio-lw/for-next'

Merge remote-tracking branch 'gpio/gpio/next'

Merge remote-tracking branch 'irqdomain/irqdomain/next'

Merge remote-tracking branch 'vhost/linux-next'

Conflicts:
drivers/vhost/Makefile

Merge remote-tracking branch 'pinctrl/for-next'

Merge remote-tracking branch 'bcon/master'

Conflicts:
drivers/block/Kconfig

20130328/char-misc

Merge remote-tracking branch 'staging/staging-next'

Merge remote-tracking branch 'usb-gadget/next'

Conflicts:
drivers/usb/chipidea/udc.c
drivers/usb/gadget/net2272.c
drivers/usb/gadget/net2280.c

Merge remote-tracking branch 'usb/usb-next'

Conflicts:
drivers/usb/serial/usb-serial.c

Merge remote-tracking branch 'tty/tty-next'

Merge remote-tracking branch 'driver-core/driver-core-next'

Merge remote-tracking branch 'leds/for-next'

Merge remote-tracking branch 'regmap/for-next'

Merge remote-tracking branch 'drivers-x86/linux-next'

Conflicts:
drivers/platform/x86/chromeos_laptop.c

Merge remote-tracking branch 'workqueues/for-next'

Merge remote-tracking branch 'xen-two/linux-next'

Merge remote-tracking branch 'kvm-ppc/kvm-ppc-next'

Merge remote-tracking branch 'kvm/linux-next'

Conflicts:
drivers/s390/kvm/virtio_ccw.c

Merge remote-tracking branch 'rcu/rcu/next'

Merge remote-tracking branch 'ftrace/for-next'

Conflicts:
kernel/trace/ftrace.c

Merge remote-tracking branch 'tip/auto-latest'

Merge remote-tracking branch 'spi-mb/spi-next'

Merge remote-tracking branch 'trivial/for-next'

Conflicts:
Documentation/virtual/virtio-spec.txt

Merge remote-tracking branch 'vfio/next'

Merge remote-tracking branch 'iommu/next'

Merge remote-tracking branch 'watchdog/master'

Merge remote-tracking branch 'selinux/master'

Merge remote-tracking branch 'security/next'

Merge remote-tracking branch 'regulator/for-next'

Merge remote-tracking branch 'omap_dss2/for-next'

Merge remote-tracking branch 'battery/master'

Merge remote-tracking branch 'mfd/master'

Merge remote-tracking branch 'md/for-next'

Merge remote-tracking branch 'slab/for-next'

Merge remote-tracking branch 'kgdb/kgdb-next'

Merge remote-tracking branch 'mmc/mmc-next'

Merge branch 'device-mapper/master'

Merge remote-tracking branch 'block/for-next'

Conflicts:
drivers/md/raid5.c

Merge remote-tracking branch 'cgroup/for-next'

Conflicts:
include/linux/res_counter.h

Merge remote-tracking branch 'input/next'

Merge remote-tracking branch 'virtio/virtio-next'

Conflicts:
drivers/char/virtio_console.c

Merge remote-tracking branch 'modules/modules-next'

Merge remote-tracking branch 'sound-asoc/for-next'

Merge remote-tracking branch 'sound/for-next'

Merge remote-tracking branch 'drm-intel/drm-intel-next-queued'

Conflicts:
drivers/gpu/drm/i915/intel_dp.c

Merge remote-tracking branch 'crypto/master'

Merge remote-tracking branch 'l2-mtd/master'

Merge remote-tracking branch 'bluetooth/master'

20130328/wireless-next

Conflicts:
net/mac80211/sta_info.c

Merge remote-tracking branch 'ipsec-next/master'

Merge remote-tracking branch 'net-next/master'

Conflicts:
drivers/nfc/microread/mei.c

Merge remote-tracking branch 'dmaengine/next'

Conflicts:
drivers/dma/ioat/dma_v3.c

20130328/slave-dma