The initial documentation was a bit incomplete, update accordingly.

[akpm@linux-foundation.org: make it more readable in 80 columns]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

for_each_online_cpu() needs the protection of {get,put}_online_cpus() so
cpu_online_mask doesn't change during the iteration.

cpu_hotplug.lock is held while a cpu is going down, it's a coarse lock
that is used kernel-wide to synchronize cpu hotplug activity.  Memcg has
a cpu hotplug notifier, called while there may not be any cpu hotplug
refcounts, which drains per-cpu event counts to memcg->nocpu_base.events
to maintain a cumulative event count as cpus disappear.  Without
get_online_cpus() in mem_cgroup_read_events(), it's possible to account
for the event count on a dying cpu twice, and this value may be
significantly large.

In fact, all memcg->pcp_counter_lock use should be nested by
{get,put}_online_cpus().

This fixes that issue and ensures the reported statistics are not vastly
over-reported during cpu hotplug.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull device tree fixes and reverts from Grant Likely:
 "One bug fix and three reverts.  The reverts back out the slightly
  controversial feeding the entire device tree into the random pool and
  the reserved-memory binding which isn't fully baked yet.  Expect the
  reserved-memory patches at least to resurface for v3.13.

  The bug fixes removes a scary but harmless warning on SPARC that was
  introduced in the v3.12 merge window.  v3.13 will contain a proper fix
  that makes the new code work on SPARC.

  On the plus side, the diffstat looks *awesome*.  I love removing lines
  of code"

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
  Revert "drivers: of: add initialization code for dma reserved memory"
  Revert "ARM: init: add support for reserved memory defined by device tree"
  Revert "of: Feed entire flattened device tree into the random pool"
  of: fix unnecessary warning on missing /cpus node

Pull DMA-mapping fix from Marek Szyprowski:
 "A bugfix for the IOMMU-based implementation of dma-mapping subsystem
  for ARM architecture"

* 'fixes-for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma-mapping: Always pass proper prot flags to iommu_map()

Pull kvm fix from Gleb Natapov.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Enable pvspinlock after jump_label_init() to avoid VM hang

Pull Xen fixes from Stefano Stabellini:
 "A small fix for Xen on x86_32 and a build fix for xen-tpmfront on
  arm64"

* tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Fix possible user space selector corruption
  tpm: xen-tpmfront: fix missing declaration of xen_domain

We use jump label to enable pv-spinlock. With the changes in (442e0973
Merge branch 'x86/jumplabel'), the jump label behaviour has changed
that would result in eventual hang of the VM since we would end up in a
situation where slow path locks would halt the vcpus but we will not be
able to wakeup the vcpu by lock releaser using unlock kick.

Similar problem in Xen and more detailed description is available in
a945928e (xen: Do not enable spinlocks before jump_label_init()
has executed)

This patch splits kvm_spinlock_init to separate jump label changes with
pvops patching and also make jump label enabling after jump_label_init().
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

This reverts commit 9d8eab7a. There is
still no consensus on the bindings for the reserved memory and various
drawbacks of the proposed solution has been shown, so the best now is to
revert it completely and start again from scratch later.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

This reverts commit 10bcdfb8. There is
no consensus on the bindings for the reserved memory, so the code for
handing it will be reverted.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

Pull vfio fix from Alex Williamson:
 "Fix an incorrect break out of nested loop in iommu mapping code"

* tag 'vfio-v3.12-rc5' of git://github.com/awilliam/linux-vfio:
  VFIO: vfio_iommu_type1: fix bug caused by break in nested loop

Pull infiniband updates from Roland Dreier:
 "Last batch of IB changes for 3.12: many mlx5 hardware driver fixes
  plus one trivial semicolon cleanup"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB: Remove unnecessary semicolons
  IB/mlx5: Ensure proper synchronization accessing memory
  IB/mlx5: Fix alignment of reg umr gather buffers
  IB/mlx5: Fix eq names to display nicely in /proc/interrupts
  mlx5: Fix error code translation from firmware to driver
  IB/mlx5: Fix opt param mask according to firmware spec
  mlx5: Fix opt param mask for sq err to rts transition
  IB/mlx5: Disable atomic operations
  mlx5: Fix layout of struct mlx5_init_seg
  mlx5: Keep polling to reclaim pages while any returned
  IB/mlx5: Avoid async events on invalid port number
  IB/mlx5: Decrease memory consumption of mr caches
  mlx5: Remove checksum on command interface commands
  IB/mlx5: Fix memory leak in mlx5_ib_create_srq
  IB/mlx5: Flush cache workqueue before destroying it
  IB/mlx5: Fix send work queue size calculation

These aren't necessary after switch blocks.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

Pull ARM fixes from Russell King:
 "Some more ARM fixes, nothing particularly major here.  The biggest
  change is to fix the SMP_ON_UP code so that it works with TI's Aegis
  cores"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7851/1: check for number of arguments in syscall_get/set_arguments()
  ARM: 7846/1: Update SMP_ON_UP code to detect A9MPCore with 1 CPU devices
  ARM: 7845/1: sharpsl_param.c: fix invalid memory access for pxa devices
  ARM: 7843/1: drop asm/types.h from generic-y
  ARM: 7842/1: MCPM: don't explode if invoked without being initialized first

Pull SLAB fix from Pekka Enberg:
 "A regression fix for overly eager slab cache name checks"

* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  slab_common: Do not check for duplicate slab names

Pull ACPI and power management fixes from Rafael Wysocki:
 "These fix two recent bugs in ACPIPHP (ACPI-based PCI hotplug) and
  update a bunch of web links and e-mail addresses in MAINTAINERS, docs
  and Kconfig that either are stale or will expire soon.

  Specifics:

   - The WARN_ON() in acpiphp_enumerate_slots() triggers as a false
     positive in some cases, so drop it.

   - Add a missing pci_dev_put() to an error code path in
     acpiphp_enumerate_slots().

   - Replace my old e-mail address that's going to expire with a new
     one.

   - Update ACPI web links and git tree information in MAINTAINERS.

   - Update links to the Linux-ACPI project's page in MAINTAINERS.

   - Update some stale links and e-mail addresses under Documentation
     and in the ACPI Kconfig file"

* tag 'pm+acpi-3.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / hotplug / PCI: Drop WARN_ON() from acpiphp_enumerate_slots()
  ACPI / hotplug / PCI: Fix error code path in acpiphp_enumerate_slots()
  ACPI / PM / Documentation: Replace outdated project links and addresses
  MAINTAINERS / ACPI: Update links to the Linux-ACPI project web page
  MAINTAINERS / ACPI: Update links and git tree information
  MAINTAINERS / Documentation: Update Rafael's e-mail address

This reverts commit 109b6236.

Tim Bird expressed concern that this will have a bad effect on boot
time, and while simple tests have shown it to be okay with simple tree,
a device tree blob can potentially be quite large and
add_device_randomness() is not a fast function. Rather than do this for
all platforms unconditionally, I'm reverting this patch and would like
to see it revisited. Instead of feeding the entire tree into the random
pool, it would probably be appropriate to hash the tree and feed the
hash result into the pool. There really isn't a lot of randomness in a
device tree anyway. In the majority of cases only a handful of
properties are going to be different between machines with the same
baseboard.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Not all DT platforms have all the cpus collected under a /cpus node.
That just happens to be a details of FDT, ePAPR and PowerPC platforms.
Sparc does something different, but unfortunately the current code
complains with a warning if /cpus isn't there. This became a problem
with commit f86e4718, "driver/core cpu: initialize of_node in cpu's
device structure", which caused the function to get called for all
architectures.

This commit is a temporary fix to fail silently if the cpus node isn't
present. A proper fix will come later to allow arch code to provide a
custom mechanism for decoding the CPU hwid if the 'reg' property isn't
appropriate.
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: David Miller <davem@davemloft.net>
Cc: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Cc: Rob Herring <rob.herring@calxeda.com>

Pull watchdog fixes from Wim Van Sebroeck:
 "This will fix a deadlock on the ts72xx_wdt driver, fix bitmasks in the
  kempld_wdt driver and fix a section mismatch in the sunxi_wdt driver"

* git://www.linux-watchdog.org/linux-watchdog:
  watchdog: sunxi: Fix section mismatch
  watchdog: kempld_wdt: Fix bit mask definition
  watchdog: ts72xx_wdt: locking bug in ioctl

This driver has a section mismatch, for probe and remove functions,
leading to the following warning during the compilation.

WARNING: drivers/watchdog/built-in.o(.data+0x24): Section mismatch in
reference from the variable sunxi_wdt_driver to the function
.init.text:sunxi_wdt_probe()
The variable sunxi_wdt_driver references
the function __init sunxi_wdt_probe()
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

STAGE_CFG bits are defined as [5:4] bits. However, '(((x) & 0x30) << 4)'
handles [9:8] bits. Thus, it should be fixed in order to handle
[5:4] bits.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Calling the WDIOC_GETSTATUS & WDIOC_GETBOOTSTATUS and twice will cause a
interruptible deadlock.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

In ftrace_syscall_enter(),
    syscall_get_arguments(..., 0, n, ...)
        if (i == 0) { <handle ORIG_r0> ...; n--;}
        memcpy(..., n * sizeof(args[0]));
If 'number of arguments(n)' is zero and 'argument index(i)' is also zero in
syscall_get_arguments(), none of arguments should be copied by memcpy().
Otherwise 'n--' can be a big positive number and unexpected amount of data
will be copied. Tracing system calls which take no argument, say sync(void),
may hit this case and eventually make the system corrupted.
This patch fixes the issue both in syscall_get_arguments() and
syscall_set_arguments().

Cc: <stable@vger.kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull ARM SoC fixes from Olof Johansson:
 "A small batch of fixes this week, mostly OMAP related.  Nothing stands
  out as particularly controversial.

  Also a fix for a 3.12-rc1 timer regression for Exynos platforms,
  including the Chromebooks"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: exynos: dts: Update 5250 arch timer node with clock frequency
  ARM: OMAP2: RX-51: Add missing max_current to rx51_lp5523_led_config
  ARM: mach-omap2: board-generic: fix undefined symbol
  ARM: dts: Fix pinctrl mask for omap3
  ARM: OMAP3: Fix hardware detection for omap3630 when booted with device tree
  ARM: OMAP2: gpmc-onenand: fix sync mode setup with DT

Without the "clock-frequency" property in arch timer node, could able
to see the below crash dump.

[<c0014e28>] (unwind_backtrace+0x0/0xf4) from [<c0011808>] (show_stack+0x10/0x14)
[<c0011808>] (show_stack+0x10/0x14) from [<c036ac1c>] (dump_stack+0x7c/0xb0)
[<c036ac1c>] (dump_stack+0x7c/0xb0) from [<c01ab760>] (Ldiv0_64+0x8/0x18)
[<c01ab760>] (Ldiv0_64+0x8/0x18) from [<c0062f60>] (clockevents_config.part.2+0x1c/0x74)
[<c0062f60>] (clockevents_config.part.2+0x1c/0x74) from [<c0062fd8>] (clockevents_config_and_register+0x20/0x2c)
[<c0062fd8>] (clockevents_config_and_register+0x20/0x2c) from [<c02b8e8c>] (arch_timer_setup+0xa8/0x134)
[<c02b8e8c>] (arch_timer_setup+0xa8/0x134) from [<c04b47b4>] (arch_timer_init+0x1f4/0x24c)
[<c04b47b4>] (arch_timer_init+0x1f4/0x24c) from [<c04b40d8>] (clocksource_of_init+0x34/0x58)
[<c04b40d8>] (clocksource_of_init+0x34/0x58) from [<c049ed8c>] (time_init+0x20/0x2c)
[<c049ed8c>] (time_init+0x20/0x2c) from [<c049b95c>] (start_kernel+0x1e0/0x39c)

THis is because the Exynos u-boot, for example on the Chromebooks, doesn't set
up the CNTFRQ register as expected by arch_timer. Instead, we have to specify
the frequency in the device tree like this.
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
[olof: Changed subject, added comment, elaborated on commit message]
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'fixes-against-v3.12-rc3-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

From Tony Lindgren:

Few fixes for omap3 related hangs and errors that people have
noticed now that people are actually using the device tree
based booting for omap3.

Also one regression fix for timer compile for dra7xx when
omap5 is not selected, and a LED regression fix for n900.

* tag 'fixes-against-v3.12-rc3-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP2: RX-51: Add missing max_current to rx51_lp5523_led_config
  ARM: mach-omap2: board-generic: fix undefined symbol
  ARM: dts: Fix pinctrl mask for omap3
  ARM: OMAP3: Fix hardware detection for omap3630 when booted with device tree
  ARM: OMAP2: gpmc-onenand: fix sync mode setup with DT
Signed-off-by: Olof Johansson <olof@lixom.net>

Pull parisc fixes from Helge Deller:
 "This patchset includes a bugfix to prevent a kernel crash when memory
  in page zero is accessed by the kernel itself, e.g.  via
  probe_kernel_read().

  Furthermore we now export flush_cache_page() which is needed
  (indirectly) by the lustre filesystem.  The other patches remove
  unused functions and optimizes the page fault handler to only evaluate
  variables if needed, which again protects against possible kernel
  crashes"

* 'parisc-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: let probe_kernel_read() capture access to page zero
  parisc: optimize variable initialization in do_page_fault
  parisc: fix interruption handler to respect pagefault_disable()
  parisc: mark parisc_terminate() noreturn and cold.
  parisc: remove unused syscall_ipi() function.
  parisc: kill SMP single function call interrupt
  parisc: Export flush_cache_page() (needed by lustre)

Pull slave-dmaengine fixes from Vinod Koul:
 "Another week, time to send another fixes request taking time out of
  extended weekend for the festivities in this part of the world.

  We have two fixes from Sergei for rcar driver and one fixing memory
  leak of edma driver by Geyslan"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dma: edma.c: remove edma_desc leakage
  rcar-hpbdma: add parameter to set_slave() method
  rcar-hpbdma: remove shdma_free_irq() calls

Signed-off-by: Helge Deller <deller@gmx.de>

The attached change defers the initialization of the variables tsk, mm
and flags until they are needed. As a result, the code won't crash if a
kernel probe is done with a corrupt context and the code will be better
optimized.
Signed-off-by: John David Anglin  <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

Running an "echo t > /proc/sysrq-trigger" crashes the parisc kernel.  The
problem is, that in print_worker_info() we try to read the workqueue info via
the probe_kernel_read() functions which use pagefault_disable() to avoid
crashes like this:
    probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
    probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
    probe_kernel_read(name, wq->name, sizeof(name) - 1);

The problem here is, that the first probe_kernel_read(&pwq) might return zero
in pwq and as such the following probe_kernel_reads() try to access contents of
the page zero which is read protected and generate a kernel segfault.

With this patch we fix the interruption handler to call parisc_terminate()
directly only if pagefault_disable() was not called (in which case
preempt_count()==0).  Otherwise we hand over to the pagefault handler which
will try to look up the faulting address in the fixup tables.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.0+
Signed-off-by: John David Anglin  <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>

Signed-off-by: Helge Deller <deller@gmx.de>

Commit 9a46ad6d "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

ERROR: "flush_cache_page" [drivers/staging/lustre/lustre/libcfs/libcfs.ko] undefined!
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>

Olga reported that file descriptors opened with O_PATH do not work with
fstatfs(), found during further development of ksh93's thread support.

There is no reason to not allow O_PATH file descriptors here (fstatfs is
very much a path operation), so use "fdget_raw()".  See commit
55815f70 ("vfs: make O_PATH file descriptors usable for 'fstat()'")
for a very similar issue reported for fstat() by the same team.
Reported-and-tested-by: ольга крыжановская <olga.kryzhanovska@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org	# O_PATH introduced in 3.0+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ext4 bugfixes from Ted Ts'o:
 "A bug fix and performance regression fix for ext4"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix memory leak in xattr
  ext4: fix performance regression in writeback of random writes

Pull btrfs fixes from Chris Mason:
 "We've got more bug fixes in my for-linus branch:

  One of these fixes another corner of the compression oops from last
  time.  Miao nailed down some problems with concurrent snapshot
  deletion and drive balancing.

  I kept out one of his patches for more testing, but these are all
  stable"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix oops caused by the space balance and dead roots
  Btrfs: insert orphan roots into fs radix tree
  Btrfs: limit delalloc pages outside of find_delalloc_range
  Btrfs: use right root when checking for hash collision

Pull sound fixes from Takashi Iwai:
 "All stable fixes except for a trivial headset mic fixup: the removal
  of bogus frame checks in snd-usb-usx2y driver that have regressed in
  the recent kernel versions, the HD-audio HDMI channel map fix, and a
  few HD-audio device-specific fixes"

* tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Sony VAIO Pro 13 (haswell) now has a working headset jack
  ALSA: hda - Add a headset mic model for ALC269 and friends
  ALSA: hda - Fix microphone for Sony VAIO Pro 13 (Haswell model)
  ALSA: hda - Add fixup for ASUS N56VZ
  ALSA: hda - hdmi: Fix channel map switch not taking effect
  ALSA: hda - Fix mono speakers and headset mic on Dell Vostro 5470
  ALSA: snd-usb-usx2y: remove bogus frame checks