I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_seb()' to 'ubi_dump_seb()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_sv()' to 'ubi_dump_sv()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_vtbl_record()' to 'ubi_dump_vtbl_record()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

I am going to remove the "UBI debugging" compilation option and make the
debugging stuff to be always compiled it. This patch is a preparation
which renames 'ubi_dbg_dump_vol_info()' to 'ubi_dump_vol_info()'.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Richard removed the "dtype" hint, but few commentaries were left and this patch
removes them. I've also added a better description about the "dtype" field in
the ubi-user.h for people who may ever wonder what was that dtype thing about.

This patch also adds an important note that it is better to use value "3" for
the "dtype" field.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This finally removes the data type hint from the UBI ABI.
>From now on the "dtype" field will be ignored and must not used
anymore.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

We do not need this feature and to our shame it even was not working
and there was a bug found very recently.
	-- Artem Bityutskiy

Without the data type hint UBI2 (fastmap) will be easier to implement.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

!!(x < y) and (x < y) are identical expressions.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Currently UBI silently retries I/O operation in case of errors. This patch
makes it emit a warning before retrying. This should allow users notice issues
earlier.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

Always dump the VID and EC headers' contents in case of errors when it
is helpful.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

Always dump the flash contents in case of errors, not only when debugging is
enabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

This patch weeds out the 'ubi_dbg_dump_stack()' function and turns it
into 'dump_stack()' - it is always useful to have stack dump in case of
an error.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

UBIFS leaks memory on error path in 'mount_ubifs()'. In case of failure in
'ubifs_fixup_free_space()', it does not call 'ubifs_lpt_free()' whereas LPT
data structures can potentially be allocated. The amount of memory leaked can
be quite high -- see 'ubifs_lpt_init()'.

The bug was introduced when moving the LPT initialisation earlier in the
mount process (commit '781c5717').
Signed-off-by: NSidney Amani <seed95@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Most functions in UBIFS follow the following designn pattern: if the function
allocates multiple resources, and failss at some point, it frees what it has
allocated and returns an error. So the caller can rely on the fact that the
callee has cleaned up everything after own failure.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NSidney Amani <seed95@gmail.com>

This patch removes the 'dbg_err()' macro and we now use 'ubifs_err()' instead.
The idea of 'dbg_err()' was to compile out some error message to make the
binary a bit smaller - but I think it was a bad idea.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Have the debugging stuff always compiled-in instead. It simplifies maintanance
a lot.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This commit re-names all functions which dump something from "dbg_dump_*()" to
"ubifs_dump_*()". This is done for consistency with UBI and because this way it
will be more logical once we remove the debugging sompilation option.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

In case of errors we almost always need the stack dump - it makes no sense
to compile it out. Remove the 'dbg_dump_stack()' function completely.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Remove CONFIG_UBIFS_FS_XATTR configuration option and associated
UBIFS_FS_XATTR ifdefs.

Testing:
       Tested using integck while using nandsim on x86 & MX28 based
       platform with Micron MT29F2G08ABAEAH4 nand.
Signed-off-by: NSubodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

"heap" is initialized twice.  I removed the first one, because it makes
Smatch complain that we use "new_cat" as an offset before checking it.

This doesn't change how the code works, it's just a cleanup.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Pull power management fixes from Rafael J. Wysocki:
 "Fix for an issue causing hibernation to hang on systems with highmem
  (that practically means i386) due to broken memory management (bug
  introduced in 3.2, so -stable material) and PM documentation update
  making the freezer documentation follow the code again after some
  recent updates."

* tag 'pm-for-3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / Freezer / Docs: Update documentation about freezing of tasks
  PM / Hibernate: fix the number of pages used for hibernate/thaw buffering

The autofs packet size has had a very unfortunate size problem on x86:
because the alignment of 'u64' differs in 32-bit and 64-bit modes, and
because the packet data was not 8-byte aligned, the size of the autofsv5
packet structure differed between 32-bit and 64-bit modes despite
looking otherwise identical (300 vs 304 bytes respectively).

We first fixed that up by making the 64-bit compat mode know about this
problem in commit a32744d4 ("autofs: work around unhappy compat
problem on x86-64"), and that made a 32-bit 'systemd' work happily on a
64-bit kernel because everything then worked the same way as on a 32-bit
kernel.

But it turned out that 'automount' had actually known and worked around
this problem in user space, so fixing the kernel to do the proper 32-bit
compatibility handling actually *broke* 32-bit automount on a 64-bit
kernel, because it knew that the packet sizes were wrong and expected
those incorrect sizes.

As a result, we ended up reverting that compatibility mode fix, and
thus breaking systemd again, in commit fcbf94b9.

With both automount and systemd doing a single read() system call, and
verifying that they get *exactly* the size they expect but using
different sizes, it seemed that fixing one of them inevitably seemed to
break the other.  At one point, a patch I seriously considered applying
from Michael Tokarev did a "strcmp()" to see if it was automount that
was doing the operation.  Ugly, ugly.

However, a prettier solution exists now thanks to the packetized pipe
mode.  By marking the communication pipe as being packetized (by simply
setting the O_DIRECT flag), we can always just write the bigger packet
size, and if user-space does a smaller read, it will just get that
partial end result and the extra alignment padding will simply be thrown
away.

This makes both automount and systemd happy, since they now get the size
they asked for, and the kernel side of autofs simply no longer needs to
care - it could pad out the packet arbitrarily.

Of course, if there is some *other* user of autofs (please, please,
please tell me it ain't so - and we haven't heard of any) that tries to
read the packets with multiple writes, that other user will now be
broken - the whole point of the packetized mode is that one system call
gets exactly one packet, and you cannot read a packet in pieces.
Tested-by: NMichael Tokarev <mjt@tls.msk.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Ian Kent <raven@themaw.net>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The file Documentation/power/freezing-of-tasks.txt was still referencing
the TIF_FREEZE flag, that was removed by the commit
d88e4cb6(freezer: remove now unused
TIF_FREEZE).

This patch removes all the references of TIF_FREEZE that were left
behind.
Signed-off-by: NMarcos Paulo de Souza <marcos.souza.org@gmail.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The actual internal pipe implementation is already really about
individual packets (called "pipe buffers"), and this simply exposes that
as a special packetized mode.

When we are in the packetized mode (marked by O_DIRECT as suggested by
Alan Cox), a write() on a pipe will not merge the new data with previous
writes, so each write will get a pipe buffer of its own.  The pipe
buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn
will tell the reader side to break the read at that boundary (and throw
away any partial packet contents that do not fit in the read buffer).

End result: as long as you do writes less than PIPE_BUF in size (so that
the pipe doesn't have to split them up), you can now treat the pipe as a
packet interface, where each read() system call will read one packet at
a time.  You can just use a sufficiently big read buffer (PIPE_BUF is
sufficient, since bigger than that doesn't guarantee atomicity anyway),
and the return value of the read() will naturally give you the size of
the packet.

NOTE! We do not support zero-sized packets, and zero-sized reads and
writes to a pipe continue to be no-ops.  Also note that big packets will
currently be split at write time, but that the size at which that
happens is not really specified (except that it's bigger than PIPE_BUF).
Currently that limit is the system page size, but we might want to
explicitly support bigger packets some day.

The main user for this is going to be the autofs packet interface,
allowing us to stop having to care so deeply about exact packet sizes
(which have had bugs with 32/64-bit compatibility modes).  But user
space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will
fail with an EINVAL on kernels that do not support this interface.
Tested-by: NMichael Tokarev <mjt@tls.msk.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Ian Kent <raven@themaw.net>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: stable@kernel.org  # needed for systemd/autofs interaction fix
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull staging tree fixes from Greg Kroah-Hartman:
 "Here are some tiny drivers/staging/ bugfixes.  Some build fixes that
  were recently reported, as well as one kfree bug that is hitting a
  number of users."

* tag 'staging-3.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ozwpan: Fix bug where kfree is called twice.
  staging: octeon-ethernet: fix build errors by including interrupt.h
  staging: zcache: fix Kconfig crypto dependency
  staging: tidspbridge: remove usage of OMAP2_L4_IO_ADDRESS

Pull USB fixes from Greg Kroah-Hartman:
 "Here are a number of small USB fixes for 3.4-rc5.

  Nothing major, as before, some USB gadget fixes.  There's a crash fix
  for a number of ASUS laptops on resume that had been reported by a
  number of different people.  We think the fix might also pertain to
  other machines, as this was a BIOS bug, and they seem to travel to
  different models and manufacturers quite easily.  Other than that,
  some other reported problems fixed as well."

* tag 'usb-3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: udc-core: fix incompatibility with dummy-hcd
  usb: gadget: udc-core: fix wrong call order
  USB: cdc-wdm: fix race leading leading to memory corruption
  USB: EHCI: fix crash during suspend on ASUS computers
  usb gadget: uvc: uvc_request_data::length field must be signed
  usb: gadget: dummy: do not call pullup() on udc_stop()
  usb: musb: davinci.c: add missing unregister
  usb: musb: drop __deprecated flag
  USB: gadget: storage gadgets send wrong error code for unknown commands
  usb: otg: gpio_vbus: Add otg transceiver events and notifiers

Pull btrfs fixes from Chris Mason:
 "This has our collection of bug fixes.  I missed the last rc because I
  thought our patches were making NFS crash during my xfs test runs.
  Turns out it was an NFS client bug fixed by someone else while I tried
  to bisect it.

  All of these fixes are small, but some are fairly high impact.  The
  biggest are fixes for our mount -o remount handling, a deadlock due to
  GFP_KERNEL allocations in readdir, and a RAID10 error handling bug.

  This was tested against both 3.3 and Linus' master as of this morning."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (26 commits)
  Btrfs: reduce lock contention during extent insertion
  Btrfs: avoid deadlocks from GFP_KERNEL allocations during btrfs_real_readdir
  Btrfs: Fix space checking during fs resize
  Btrfs: fix block_rsv and space_info lock ordering
  Btrfs: Prevent root_list corruption
  Btrfs: fix repair code for RAID10
  Btrfs: do not start delalloc inodes during sync
  Btrfs: fix that check_int_data mount option was ignored
  Btrfs: don't count CRC or header errors twice while scrubbing
  Btrfs: fix btrfs_ioctl_dev_info() crash on missing device
  btrfs: don't return EINTR
  Btrfs: double unlock bug in error handling
  Btrfs: always store the mirror we read the eb from
  fs/btrfs/volumes.c: add missing free_fs_devices
  btrfs: fix early abort in 'remount'
  Btrfs: fix max chunk size check in chunk allocator
  Btrfs: add missing read locks in backref.c
  Btrfs: don't call free_extent_buffer twice in iterate_irefs
  Btrfs: Make free_ipath() deal gracefully with NULL pointers
  Btrfs: avoid possible use-after-free in clear_extent_bit()
  ...

Pull ARM SoC fixes from Olof Johansson:
 "Nothing controversial, just another batch of fixes:

   - Samsung/exynos fixes for more merge window fallout: build errors
     and warnings mostly, but also some clock/device setup issues on
     exynos4/5
   - PXA bug and warning fixes related to gpio and pinmux
   - IRQ domain conversion bugfixes for U300 and MSM
   - A regulator setup fix for U300"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: PXA2xx: MFP: fix potential direction bug
  ARM: PXA2xx: MFP: fix bug with MFP_LPM_KEEP_OUTPUT
  arm/sa1100: fix sa1100-rtc memory resource
  ARM: pxa: fix gpio wakeup setting
  ARM: SAMSUNG: add missing MMC_CAP2_BROKEN_VOLTAGE capability
  ARM: EXYNOS: Fix compilation error when CONFIG_OF is not defined
  ARM: EXYNOS: Fix resource on dev-dwmci.c
  ARM: S3C24XX: Fix build warning for S3C2410_PM
  ARM: mini2440_defconfig: Fix build error
  ARM: msm: Fix gic irqdomain support
  ARM: EXYNOS: Fix incorrect initialization of GIC
  ARM: EXYNOS: use 'exynos4-sdhci' as device name for sdhci controllers
  ARM: u300: bump all IRQ numbers by one
  ARM: ux300: Fix unimplementable regulation constraints

Pull drm fixes from Dave Airlie:
 "As soon as I sent the non-urgent stack, two important fixes come in:

   - i915: fixes SNB GPU hangs in a number of 3D apps

   - radeon: initial fix for VGA on LLano system, 3 or 4 of us have
     spent time debugging this, and Jerome finally figured out the magic
     bit the BIOS/fglrx set that we didn't.  This at least should get
     things working, there may be future reliability fixes."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Set the Stencil Cache eviction policy to non-LRA mode.
  drm/radeon/kms: need to set up ss on DP bridges as well

This reverts commit a32744d4.

While that commit was technically the right thing to do, and made the
x86-64 compat mode work identically to native 32-bit mode (and thus
fixing the problem with a 32-bit systemd install on a 64-bit kernel), it
turns out that the automount binaries had workarounds for this compat
problem.

Now, the workarounds are disgusting: doing an "uname()" to find out the
architecture of the kernel, and then comparing it for the 64-bit cases
and fixing up the size of the read() in automount for those.  And they
were confused: it's not actually a generic 64-bit issue at all, it's
very much tied to just x86-64, which has different alignment for an
'u64' in 64-bit mode than in 32-bit mode.

But the end result is that fixing the compat layer actually breaks the
case of a 32-bit automount on a x86-64 kernel.

There are various approaches to fix this (including just doing a
"strcmp()" on current->comm and comparing it to "automount"), but I
think that I will do the one that teaches pipes about a special "packet
mode", which will allow user space to not have to care too deeply about
the padding at the end of the autofs packet.

That change will make the compat workaround unnecessary, so let's revert
it first, and get automount working again in compat mode.  The
packetized pipes will then fix autofs for systemd.
Reported-and-requested-by: NMichael Tokarev <mjt@tls.msk.ru>
Cc: Ian Kent <raven@themaw.net>
Cc: stable@kernel.org # for 3.3
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clearing bit 5 of CACHE_MODE_0 is necessary to prevent GPU hangs in
OpenGL programs such as Google MapsGL, Google Earth, and gzdoom when
using separate stencil buffers.  Without it, the GPU tries to use the
LRA eviction policy, which isn't supported.  This was supposed to be off
by default, but seems to be on for many machines.

This cannot be done in gen6_init_clock_gating with most of the other
workaround bits; the render ring needs to exist.  Otherwise, the
register write gets dropped on the floor (one printk will show it
changed, but a second printk immediately following shows the value
reverts to the old one).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=47535
Cc: stable@vger.kernel.org
Cc: Rob Castle <futuredub@gmail.com>
Cc: Eric Appleman <erappleman@gmail.com>
Cc: aaron667@gmx.net
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Makes Nutmeg DP to VGA bridges work for me.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=42490

Noticed by Jerome Glisse (after weeks of debugging).
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Pull CIFS fixes from Steve French.

* git://git.samba.org/sfrench/cifs-2.6:
  Use correct conversion specifiers in cifs_show_options
  CIFS: Show backupuid/gid in /proc/mounts
  cifs: fix offset handling in cifs_iovec_write

Merge tag 'stable/for-linus-3.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Some of these had been in existence since the 2.6.27 days, some since
  3.0 - and some due to new features added in v3.4.

  The one that is most interesting is David's one - in the low-level
  assembler code we had be checking events needlessly.  With his patch
  now we do it when the appropriate flag is set - with the added benefit
  that we can process events faster.  Stefano's is fixing a mistake
  where the Linux IRQ numbers were ACK-ed instead of the Xen IRQ,
  resulting in missing interrupts.  The other ones are bootup related
  that can show up on various hardware."

 - In the low-level assembler code we would jump to check events even if
   none were present.  This incorrect behavior had been there since
   2.6.27 days!
 - When using the fast-path for ACK-ing interrupts we were using the
   Linux IRQ numbers instead of the Xen ones (and they can differ) and
   missing interrupts in process.
 - Fix bootup crashes when ACPI hotplug CPUs were present and they would
   expand past the set number of CPUs we were allocated.
 - Deal with broken BIOSes when uploading C-states to the hypervisor.
 - Disable the cpuid check for MWAIT_LEAF if the ACPI PAD driver is
   loaded.  If the ACPI PAD driver is used it will crash, so lets not
   export the functionality so the ACPI PAD driver won't load.

* tag 'stable/for-linus-3.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: correctly check for pending events when restoring irq flags
  xen/acpi: Workaround broken BIOSes exporting non-existing C-states.
  xen/smp: Fix crash when booting with ACPI hotplug CPUs.
  xen: use the pirq number to check the pirq_eoi_map
  xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded.

Pull misc SPI device driver bug fixes from Grant Likely.

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  spi/spi-bfin5xx: Fix flush of last bit after each spi transfer
  spi/spi-bfin5xx: fix reversed if condition in interrupt mode
  spi/spi_bfin_sport: drop bits_per_word from client data
  spi/bfin_spi: drop bits_per_word from client data
  spi/spi-bfin-sport: move word length setup to transfer handler
  spi/bfin5xx: rename config macro name for bfin5xx spi controller driver
  spi/pl022: Allow request for higher frequency than maximum possible
  spi/bcm63xx: set master driver mode_bits.
  spi/bcm63xx: don't use the stopping state
  spi/bcm63xx: convert to the pump message infrastructure
  spi/spi-ep93xx.c: use dma_transfer_direction instead of dma_data_direction
  spi: fix spi.h kernel-doc warning
  spi/pl022: Fix calculate_effective_freq()
  spi/pl022: Fix range checking for bits per word

Pull hwmon patches from Guenter Roeck:
 - Fix build warning in ad7314 driver
 - Fix pci_device_id array access in fam15h_power driver, introduced by
   commit 00250ec9 ("hwmon: fam15h_power: fix bogus values with
   current BIOSes")

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (fam15h_power) Fix pci_device_id array
  hwmon: (ad7314) Fix build warning

Pull drm fixes from Dave Airlie:
 "For your Friday pull request stack, nothing astounding or shattering
  this week some exynos, some intel, some radeon fixes.  One intel fix
  for a regression somwehere back in 2.6.35 land."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms: use frac fb div on APUs
  drm/radeon: add a missing entry to encoder_names
  drm/i915: handle input/output sdvo timings separately in mode_set
  drm/i915: fix integer overflow in i915_gem_do_execbuffer()
  drm/i915: fix integer overflow in i915_gem_execbuffer2()
  drm/exynos: added missed vm area region mapping type.
  drm/exynos: fixed exynos_drm_gem_map_pages bug.
  drm/exynos: fixed duplicatd memory allocation bug.
  drm/i915: fixup load-detect on enabled, but not active pipe

Pull RCU fix from Ingo Molnar.

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Permit call_rcu() from CPU_DYING notifiers