- Fix a regression in 16-bit Atmel NAND flash which was introduced in 3.1
 - Fix breakage with MTD suspend caused by the API rework
 - Fix a problem with resetting the MX28 BCH module
 - A couple of other trivial fixes

* tag 'for-linus-3.3-20120204' of git://git.infradead.org/~dwmw2/mtd-3.3:
  Revert "mtd: atmel_nand: optimize read/write buffer functions"
  mtd: fix MTD suspend
  jffs2: do not initialize variable unnecessarily
  mtd: gpmi-nand bugfix: reset the BCH module when it is not MX23
  mtd: nand: fix typo in comment

This reverts commit fb542750.

The reason is that it breaks 16 bits NAND flash as it was reported by
Nikolaus Voss and confirmed by Eric Bénard.

Nicolas Ferre <nicolas.ferre@atmel.com> alco confirmed:
"After double checking with designers, I must admit that I misunderstood
the way of optimizing accesses to SMC. 16 bit nand is not so common
those days..."
Reported-by: NNikolaus Voss <n.voss@weinmann.de>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.1+]

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7314/1: kuser: consistently use usr_ret for returning from helpers
  ARM: 7302/1: Add TLB flushing for both entries in a PMD
  ARM: 7303/1: perf: add empty NODE event definitions for Cortex-A5 and Cortex-A15
  ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers
  ARM: 7307/1: vfp: fix ptrace regset modification race
  ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe
  Revert "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"

Trivial kmemleak bug-fixes:

 - Early logging doesn't stop when kmemleak is off by default.
 - Zero-size scanning areas should be ignored (currently it prints a
   warning).

* tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux:
  kmemleak: Disable early logging when kmemleak is off by default
  kmemleak: Only scan non-zero-size areas

sound fixes for 3.3-rc3

Most of commits are either regression fixes for varioud HD-audio
codecs or small ASoC fixes.  Also a trivial build fix is included.

* tag 'sound-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Disable dynamic-power control for VIA as default
  ALSA: hda - Allow analog low-current mode when dynamic power-control is on
  ALSA: hda - Fix the logic to detect VIA analog low-current mode
  ALSA: hda - Check power-state before changing in patch_via.c
  ALSA: HDA: Fix duplicated output to more than one codec
  ALSA: hda - Fix calling cs_automic twice for Cirrus codecs.
  ALSA: HDA: Remove quirk for Toshiba Qosmio G50
  ALSA: HDA: Fix jack creation for codecs with front and rear Line In
  ALSA: hda - Apply 0x0f-VREF fix to all ASUS laptops with ALC861/660
  ASoC: neo1973_wm8753: remove references to the neo1973-gta01 machine
  ALSA: Add #ifdef CONFIG_PCI guard for snd_pci_quirk_* functions
  ASoC: wm_hubs: fix wrong bits for LINEOUT2 N/P mixer
  ALSA: HDA: Remove quirk for Asus N53Jq
  ASoC: wm_hubs: Enable line out VMID buffer for single ended line outputs
  ASoC: wm5100: Mark register cache as dirty when regulators are disabled
  ASoC: wm8962: Mark register cache as dirty when regulators are disabled
  ASoC: wm8996: Mark register cache as dirty when regulators are disabled
  ASoC: wm5100: Fix microphone configuration
  ASoC: wm5100: Make sure we switch to button reporting mode

__kuser_cmpxchg64 has a return path using bx lr to get back to the caller.
This is actually ok since the code in question is predicated on
CONFIG_CPU_32v6K, but for the sake of consistency using the usr_ret
macro is probably better.
Acked-by: NDave Martin <dave.martin@linaro.org>
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix safety of rbd_put_client()
  rbd: fix a memory leak in rbd_get_client()
  ceph: create a new session lock to avoid lock inversion
  ceph: fix length validation in parse_reply_info()
  ceph: initialize client debugfs outside of monc->mutex
  ceph: change "ceph.layout" xattr to be "ceph.file.layout"

Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The rbd_client structure uses a kref to arrange for cleaning up and
freeing an instance when its last reference is dropped.  The cleanup
routine is rbd_client_release(), and one of the things it does is
delete the rbd_client from rbd_client_list.  It acquires node_lock
to do so, but the way it is done is still not safe.

The problem is that when attempting to reuse an existing rbd_client,
the structure found might already be in the process of getting
destroyed and cleaned up.

Here's the scenario, with "CLIENT" representing an existing
rbd_client that's involved in the race:

 Thread on CPU A                | Thread on CPU B
 ---------------                | ---------------
 rbd_put_client(CLIENT)         | rbd_get_client()
   kref_put()                   |   (acquires node_lock)
     kref->refcount becomes 0   |   __rbd_client_find() returns CLIENT
     calls rbd_client_release() |   kref_get(&CLIENT->kref);
                                |   (releases node_lock)
       (acquires node_lock)     |
       deletes CLIENT from list | ...and starts using CLIENT...
       (releases node_lock)     |
       and frees CLIENT         | <-- but CLIENT gets freed here

Fix this by having rbd_put_client() acquire node_lock.  The result
could still be improved, but at least it avoids this problem.
Signed-off-by: NAlex Elder <elder@dreamhost.com>
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes the race in process_vm_core found by Oleg (see

  http://article.gmane.org/gmane.linux.kernel/1235667/

for details).

This has been updated since I last sent it as the creation of the new
mm_access() function did almost exactly the same thing as parts of the
previous version of this patch did.

In order to use mm_access() even when /proc isn't enabled, we move it to
kernel/fork.c where other related process mm access functions already
are.
Signed-off-by: NChris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If an existing rbd client is found to be suitable for use in
rbd_get_client(), the rbd_options structure is not being
freed as it should.  Fix that.
Signed-off-by: NAlex Elder <elder@dreamhost.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.
Signed-off-by: NAlex Elder <elder@dreamhost.com>
Reviewed-by: NSage Weil <sage@newdream.net>

"len" is read from network and thus needs validation.  Otherwise, given
a bogus "len" value, p+len could be an out-of-bounds pointer, which is
used in further parsing.
Signed-off-by: NXi Wang <xi.wang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Initializing debufs under monc->mutex introduces a lock dependency for
sb->s_type->i_mutex_key, which (combined with several other dependencies)
leads to an annoying lockdep warning.  There's no particular reason to do
the debugfs setup under this lock, so move it out.

It used to be the case that our first monmap could come from the OSD; that
is no longer the case with recent servers, so we will reliably set up the
client entry during the initial authentication.

We don't have to worry about racing with debugfs teardown by
ceph_debugfs_client_cleanup() because ceph_destroy_client() calls
ceph_msgr_flush() first, which will wait for the message dispatch work
to complete (and the debugfs init to complete).

Fixes: #1940
Signed-off-by: NSage Weil <sage@newdream.net>

The virtual extended attribute named "ceph.layout" is meaningful
only for regular files.  Change its name to be "ceph.file.layout" to
more directly reflect that in the ceph xattr namespace.  Preserve
the old "ceph.layout" name for the time being (until we decide it's
safe to get rid of it entirely).

Add a missing initializer for "readonly" in the terminating entry.
Signed-off-by: NAlex Elder <elder@dreamhost.com>
Reviewed-by: NSage Weil <sage@newdream.net>

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms/blit: fix blit copy for very large buffers
  drm/radeon/kms: fix TRAVIS panel setup
  drm/radeon: fix use after free in ATRM bios reading code.
  drm/radeon/kms: Fix device tree linkage of DP i2c buses too
  drm/radeon: Set DESKTOP_HEIGHT register to the framebuffer (not mode) height.
  drm/radeon/kms: disable output polling when suspended
  drm/nv50/pm: signedness bug in nv50_pm_clocks_pre()
  drm/nouveau/gem: fix fence_sync race / oops
  drm/nouveau: fix typo on mxmdcb option
  drm/nouveau/mxm: pretend to succeed, even if we can't shadow the MXM-SIS
  drm/nouveau/disp: check that panel power gpio is enabled at init time

* 'next' of git://git.monstr.eu/linux-2.6-microblaze:
  Revert "microblaze: Add topology init"

Merge branches 'core-urgent-for-linus', 'perf-urgent-for-linus', 'sched-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  bugs, x86: Fix printk levels for panic, softlockups and stack dumps

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf top: Fix number of samples displayed
  perf tools: Fix strlen() bug in perf_event__synthesize_event_type()
  perf tools: Fix broken build by defining _GNU_SOURCE in Makefile
  x86/dumpstack: Remove unneeded check in dump_trace()
  perf: Fix broken interrupt rate throttling

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW
  sched: Fix ancient race in do_exit()
  sched/nohz: Fix nohz cpu idle load balancing state with cpu hotplug
  sched/s390: Fix compile error in sched/core.c
  sched: Fix rq->nr_uninterruptible update race

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Remove VersaLogic Menlow reboot quirk
  x86/reboot: Skip DMI checks if reboot set by user
  x86: Properly parenthesize cmpxchg() macro arguments

Linux uses two PMD entries for a PTE with the classic page table format,
covering 2MB range. However, the __pte_free_tlb() function only adds a
single TLB flush corresponding to 1MB range covering 'addr'. On
Cortex-A15, level 1 entries can be cached by the TLB independently of
the level 2 entries and without additional flushing a PMD entry would be
left pointing at the wrong PTE. The patch limits the TLB flushing range
to two 4KB pages around the 1MB boundary within PMD.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit 89d6c0b5 ("perf, arch: Add generic NODE cache events") added
empty NODE event definitions for the ARM PMU implementations. This was
merged along with Cortex-A5 and Cortex-A15 PMU support, so they missed
out on the original patch.

This patch adds the empty definitions to Cortex-A5 and Cortex-A15.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If we are context switched whilst copying into a thread's
vfp_hard_struct then the partial copy may be corrupted by the VFP
context switching code (see "ARM: vfp: flush thread hwstate before
restoring context from sigframe").

This patch updates the ptrace VFP set code so that the thread state is
flushed before the copy, therefore disabling VFP and preventing
corruption from occurring.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

In a preemptible kernel, vfp_set() can be preempted, causing the
hardware VFP context to be switched while the thread vfp state is
being read and modified.  This leads to a race condition which can
cause the thread vfp state to become corrupted if lazy VFP context
save occurs due to preemption in between the time thread->vfpstate
is read and the time the modified state is written back.

This may occur if preemption occurs during the execution of a
ptrace() call which modifies the VFP register state of a thread.
Such instances should be very rare in most realistic scenarios --
none has been reported, so far as I am aware.  Only uniprocessor
systems should be affected, since VFP context save is not currently
lazy in SMP kernels.

The problem was introduced by my earlier patch migrating to use
regsets to implement ptrace.

This patch does a vfp_sync_hwstate() before reading
thread->vfpstate, to make sure that the thread's VFP state is not
live in the hardware registers while the registers are modified.

Thanks to Will Deacon for spotting this.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: NDave Martin <dave.martin@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Following execution of a signal handler, we currently restore the VFP
context from the ucontext in the signal frame. This involves copying
from the user stack into the current thread's vfp_hard_struct and then
flushing the new data out to the hardware registers.

This is problematic when using a preemptible kernel because we could be
context switched whilst updating the vfp_hard_struct. If the current
thread has made use of VFP since the last context switch, the VFP
notifier will copy from the hardware registers into the vfp_hard_struct,
overwriting any data that had been partially copied by the signal code.

Disabling preemption across copy_from_user calls is a terrible idea, so
instead we move the VFP thread flush *before* we update the
vfp_hard_struct. Since the flushing is performed lazily, this has the
effect of disabling VFP and clearing the CPU's VFP state pointer,
therefore preventing the thread from being updated with stale data on
the next context switch.

Cc: stable <stable@vger.kernel.org>
Tested-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This reverts commit 3c424f35.

Joachim Eastwood reports:
| "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"
| Commit: 3c424f35 in Linus master
|
| Breaks booting on my custom AT91RM9200 board.
| There isn't any error messages or anything that indicates what goes
| wrong it just stops after; Uncompressing Linux... done, booting the
| kernel.
|
| Reverting it makes my board boot again.

and further debugging reveals:

ioremap: pfn=fffff phys=fffff000 offset=400 size=1000
ioremap: area c3ffdfc0: phys_addr=200000 pfn=200 size=4000
ioremap: found: addr fef74000 => fed73000 => fed73400

Clearly, an area for pfn 0x200, 16K can't ever satisfy a request for pfn
0xfffff.  This happens because the changed if statement becomes:

                if (0x00200 > 0xfffff ||
                    0xfffff000 + 0x400 + 0x1000-1 > 0x00200000 + 0x4000-1)
and therefore:
                if (0x00200 > 0xfffff ||
                    0x000003ff > 0x00203fff)

The if condition fails, and so we _believe_ that the SRAM mapping fits
our request.  Clearly that's totally bogus.

Moreover, the original premise of the 'fix' patch was wrong:
|    The condition checking boundaries of the requested and existing
|    mappings didn't take in-page offset into consideration though,
|    which lead to obscure and hard to debug problems when requested
|    mapping crossed end of the static one.

as the code immediately above this loop does:

        size = PAGE_ALIGN(offset + size);

so 'size' already contains the requested offset into the page.

So, revert the broken 'fix'.
Acked-by: NNicolas Pitre <nico@linaro.org>

Evergreen and NI blit copy was broken if the buffer maps to a rectangle
whose one dimension is 16384 (max dimension allowed by these chips).
In the mainline kernel, the problem is exposed only when buffers are
very large (1G), but it's still a problem. The problem could be exposed
for smaller buffers if anyone modifies the algorithm for rectangle
construction in r600_blit_create_rect() (the reason why someone would
modify that algorithm is to tune the performance of buffer moves).

The root cause was in i2f() function which only operated on range between
0 and 16383. Fix this by extending the range of i2f() function to 0 to
32767.

While at it improve the function so that the range can be easily
extended in the future (if it becomes necessary), cleanup lines
over 80 characters, and replace in-line comments with one strategic
comment that explains the crux of the function.

Credits to michel@daenzer.net for pointing out the root cause of
the bug.

v2: Fix I2F_MAX_INPUT constant definition goof and warn only once
    if input argument is out of range. Edit the comment a little
    bit to avoid some linguistic confusion and make it look better
    in general.
Signed-off-by: NIlija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NMichel Dänzer <michel@daenzer.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Different versions of the DP to LVDS bridge chip
need different panel mode settings depending on
the chip version used.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=41569Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=45503

Reported-and-Debugged-by: mlambda@gmail.com
Signed-off-by: NDave Airlie <airlied@redhat.com>

Since the dynamic pin power-control and the analog low-current mode
may lead to pop-noise, it's safer to set it off as default.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=741128

Cc: <stable@kernel.org> [v3.1+]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

VIA codecs have several different power-saving features, and one of
them is the analog low-current mode.  But it turned out that the ALC
mode causes pop-noises at each on/off time on some machines.  As a
quick workaround, disable the ALC when another power-saving feature,
the dynamic pin power-control, is turned off, too, since the dynamic
power-control is already exposed as a mixer enum element so that user
can turn it on/off freely.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=741128

Cc: <stable@kernel.org> [v3.1+]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The analog low-current mode must be enabled when the no stream is
running but the current detection checks it in a wrong way.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=741128

Cc: <stable@kernel.org> [v3.1+]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Instead of always writing AC_VERB_SET_POWER_STATE, check the current
power-state and don't write again if the value is already set.
This may reduce the click noise upon the dynamic power-state change
(e.g. in analog-input mixer).
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

firewire fixes post v3.3-rc1

Add workarounds table entries for hardware bugs in
  - FireWire part of Sound Blaster Audigy cards,
  - Ricoh PCIe 1394 controllers.
Without these, several protocols, e.g. AV/C, do not work on the
Audigy, and the Ricoh PCIe controllers wouldn't work at all.
This does not concern the older Ricoh PCI controllers.

* tag 'firewire-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: ohci: disable MSI on Ricoh controllers
  firewire: ohci: add reset packet quirk for SB Audigy

Add MODULE_LICENSE() as per the license in the comment at the top of the
file for this source module to fix build warning:

  WARNING: modpost: missing MODULE_LICENSE() in drivers/staging/media/go7007/go7007-usb.o
  see include/linux/module.h for more information
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Ross Cohen <rcohen@snurgle.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix 2 fatal errors in the device-drivers docbook.
Also add some missing files from drivers/base/; since several
of these are DMA-related, add a section for DMA Management.

docproc: drivers/base/sys.c: No such file or directory
docproc: drivers/tty/serial/8250.c: No such file or directory
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  lib: Fix 32-bit sparc udiv_qrnnd() definition in mpilib's longlong.h
  lib: Fix multiple definitions of clz_tab
  lib/digsig: checks for NULL return value
  lib/mpi: added missing NULL check
  lib/mpi: added comment on divide by 0 case
  lib/mpi: check for possible zero length
  lib/digsig: pkcs_1_v1_5_decode_emsa cleanup
  lib/digsig: additional sanity checks against badly formated key payload
  lib/mpi: removed unused functions
  lib/mpi: checks for zero divisor length
  lib/mpi: return error code on dividing by zero
  lib/mpi: replaced MPI_NULL with normal NULL
  lib/mpi: added missing NULL check

This copy of longlong.h is extremely dated and results in compile
errors on sparc32 when MPILIB is enabled, copy over the more uptodate
implementation from arch/sparc/math/sfp-util_32.h
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Morris <jmorris@namei.org>

Both sparc 32-bit's software divide assembler and MPILIB provide
clz_tab[] with identical contents.

Break it out into a seperate object file and select it when
SPARC32 or MPILIB is set.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Morris <jmorris@namei.org>

InfiniBand/RDMA fixes for 3.3:

 - Fix a crash due to a regression (uninitialized refcnt) introduced in
   3.2 with XRC support.
 - Close race in how ucma reports events when connect fails.
 - Process vendor-specific MADs in mlx4 so that eg FDR-10 data rate works.
 - Fix regression in qib caused by over-aggressive PCIe tuning.
 - Other small fixes for hardware drivers (ipath, nes, qib).

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  RDMA/nes: Copyright update
  IB/mlx4: pass SMP vendor-specific attribute MADs to firmware
  RDMA/nes: Fix fast memory registration opcode
  RDMA/nes: Fix fast memory registration length
  RDMA/ucma: Discard all events for new connections until accepted
  IB/qib: Roll back PCIe tuning change
  IB/qib: Use GFP_ATOMIC when locks are held
  RDMA/nes: Add missing rcu_read_unlock() in nes_addr_resolve_neigh()
  RDMA/nes: Fix for sending MPA reject frame
  IB/ipath: Calling PTR_ERR() on right variable in create_file()
  RDMA/core: Fix kernel panic by always initializing qp->usecnt

Once /proc/pid/mem is opened, the memory can't be released until
mem_release() even if its owner exits.

Change mem_open() to do atomic_inc(mm_count) + mmput(), this only
pins mm_struct. Change mem_rw() to do atomic_inc_not_zero(mm_count)
before access_remote_vm(), this verifies that this mm is still alive.

I am not sure what should mem_rw() return if atomic_inc_not_zero()
fails. With this patch it returns zero to match the "mm == NULL" case,
may be it should return -EINVAL like it did before e268337d.

Perhaps it makes sense to add the additional fatal_signal_pending()
check into the main loop, to ensure we do not hold this memory if
the target task was oom-killed.

Cc: stable@kernel.org
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No functional changes, cleanup and preparation.

mem_read() and mem_write() are very similar. Move this code into the
new common helper, mem_rw(), which takes the additional "int write"
argument.

Cc: stable@kernel.org
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>