get_wchan() is lockless. Task may wakeup at any time and change its own stack,
thus each next stack frame may be overwritten and filled with random stuff.
Signed-off-by: NKonstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

ARMv8 CPUs can perform efficient unaligned memory accesses in hardware
and this feature is relied up on by code such as the dcache
word-at-a-time name hashing.

This patch selects HAVE_EFFICIENT_UNALIGNED_ACCESS for arm64.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad in much the
same way as has been done for ARM, although big-endian systems are also
supported.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

AArch64 instructions must be 4-byte aligned, so make sure this is true
for the futex .fixup section.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch implements the word-at-a-time interface for arm64 using the
same algorithm as ARM. We use the fls64 macro, which expands to a clz
instruction via a compiler builtin. Big-endian configurations make use
of the implementation from asm-generic.

With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch implements optimised percpu variable accesses using the
el1 r/w thread register (tpidr_el1) along the same lines as arch/arm/.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Add support for irq registration when pmu interrupt is percpu.
Signed-off-by: NVinayak Kale <vkale@apm.com>
Signed-off-by: NTuan Phan <tphan@apm.com>
[will: tidied up cross-calling to pass &irq]
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds an accessor function for IRQ_PER_CPU flag.
The accessor function is useful to determine whether an IRQ is percpu or not.

This patch is based on an older patch posted by Chris Smith here [1].
There is a minor change w.r.t. Chris's original patch: The accessor function
is renamed as 'irq_is_percpu' instead of 'irq_is_per_cpu'.

[1]: http://lkml.indiana.edu/hypermail/linux/kernel/1207.3/02955.htmlSigned-off-by: NChris Smith <chris.smith@st.com>
Signed-off-by: NVinayak Kale <vkale@apm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We currently try to emit .comment twice, once in STABS_DEBUG, and once
in the line immediately following it. As the two section definitions are
identical, the latter is redundant and can be dropped.

This patch drops the redundant .comment section definition.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Describe the virtio device so we can mount disk images in the simulator.

[Reduced the size of the region based on feedback from review -- broonie]
Signed-off-by: NMark Hambleton <mahamble@broadcom.com>
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

For NUMA systems, initializing the blk-mq layer and using per node hctx.
We initialize submit queues to 1, while blk-mq nr_hw_queues is
initialized to the number of NUMA nodes.

This makes the null_init_hctx function overwrite memory outside of what
it allocated.  In my case it lead to writing garbage into struct
request_queue's mq_map.
Signed-off-by: NMatias Bjorling <m@bjorling.me>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit ec39f64b ("drm/radeon/dpm: Convert to use
devm_hwmon_register_with_groups") radeon_hwmon_init() is using
hwmon_device_register_with_groups(), which sets `rdev' as a device
private driver_data, while hwmon_attributes_visible() and
radeon_hwmon_show_temp_thresh() are still waiting for `drm_device'.

Fix them by using dev_get_drvdata(), in order to avoid this oops:

  BUG: unable to handle kernel paging request at 0000000000001e28
  IP: [<ffffffffa02ae8b4>] hwmon_attributes_visible+0x18/0x3d [radeon]
  PGD 15057e067 PUD 151a8e067 PMD 0
  Oops: 0000 [#1] PREEMPT SMP
  Call Trace:
    internal_create_group+0x114/0x1d9
    sysfs_create_group+0xe/0x10
    sysfs_create_groups+0x22/0x5f
    device_add+0x34f/0x501
    device_register+0x15/0x18
    hwmon_device_register_with_groups+0xb5/0xed
    radeon_hwmon_init+0x56/0x7c [radeon]
    radeon_pm_init+0x134/0x7e5 [radeon]
    radeon_modeset_init+0x75f/0x8ed [radeon]
    radeon_driver_load_kms+0xc6/0x187 [radeon]
    drm_dev_register+0xf9/0x1b4 [drm]
    drm_get_pci_dev+0x98/0x129 [drm]
    radeon_pci_probe+0xa3/0xac [radeon]
    pci_device_probe+0x6e/0xcf
    driver_probe_device+0x98/0x1c4
    __driver_attach+0x5c/0x7e
    bus_for_each_dev+0x7b/0x85
    driver_attach+0x19/0x1b
    bus_add_driver+0x104/0x1ce
    driver_register+0x89/0xc5
    __pci_register_driver+0x58/0x5b
    drm_pci_init+0x86/0xea [drm]
    radeon_init+0x97/0x1000 [radeon]
    do_one_initcall+0x7f/0x117
    load_module+0x1583/0x1bb4
    SyS_init_module+0xa0/0xaf
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Revert CHECKSUM_COMPLETE optimization in pskb_trim_rcsum(), I can't
    figure out why it breaks things.

 2) Fix comparison in netfilter ipset's hash_netnet4_data_equal(), it
    was basically doing "x == x", from Dave Jones.

 3) Freescale FEC driver was DMA mapping the wrong number of bytes, from
    Sebastian Siewior.

 4) Blackhole and prohibit routes in ipv6 were not doing the right thing
    because their ->input and ->output methods were not being assigned
    correctly.  Now they behave properly like their ipv4 counterparts.
    From Kamala R.

 5) Several drivers advertise the NETIF_F_FRAGLIST capability, but
    really do not support this feature and will send garbage packets if
    fed fraglist SKBs.  From Eric Dumazet.

 6) Fix long standing user triggerable BUG_ON over loopback in RDS
    protocol stack, from Venkat Venkatsubra.

 7) Several not so common code paths can potentially try to invoke
    packet scheduler actions that might be NULL without checking.  Shore
    things up by either 1) defining a method as mandatory and erroring
    on registration if that method is NULL 2) defininig a method as
    optional and the registration function hooks up a default
    implementation when NULL is seen.  From Jamal Hadi Salim.

 8) Fix fragment detection in xen-natback driver, from Paul Durrant.

 9) Kill dangling enter_memory_pressure method in cg_proto ops, from
    Eric W Biederman.

10) SKBs that traverse namespaces should have their local_df cleared,
    from Hannes Frederic Sowa.

11) IOCB file position is not being updated by macvtap_aio_read() and
    tun_chr_aio_read().  From Zhi Yong Wu.

12) Don't free virtio_net netdev before releasing all of the NAPI
    instances.  From Andrey Vagin.

13) Procfs entry leak in xt_hashlimit, from Sergey Popovich.

14) IPv6 routes that are no cached routes should not count against the
    garbage collection limits.  We had this almost right, but were
    missing handling addrconf generated routes properly.  From Hannes
    Frederic Sowa.

15) fib{4,6}_rule_suppress() have to consider potentially seeing NULL
    route info when they are called, from Stefan Tomanek.

16) TUN and MACVTAP have had truncated packet signalling for some time,
    fix from Jason Wang.

17) Fix use after frrr in __udp4_lib_rcv(), from Eric Dumazet.

18) xen-netback does not interpret the NAPI budget properly for TX work,
    fix from Paul Durrant.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (132 commits)
  igb: Fix for issue where values could be too high for udelay function.
  i40e: fix null dereference
  xen-netback: fix gso_prefix check
  net: make neigh_priv_len in struct net_device 16bit instead of 8bit
  drivers: net: cpsw: fix for cpsw crash when build as modules
  xen-netback: napi: don't prematurely request a tx event
  xen-netback: napi: fix abuse of budget
  sch_tbf: use do_div() for 64-bit divide
  udp: ipv4: must add synchronization in udp_sk_rx_dst_set()
  net:fec: remove duplicate lines in comment about errata ERR006358
  Revert "8390 : Replace ei_debug with msg_enable/NETIF_MSG_* feature"
  8390 : Replace ei_debug with msg_enable/NETIF_MSG_* feature
  xen-netback: make sure skb linear area covers checksum field
  net: smc91x: Fix device tree based configuration so it's usable
  udp: ipv4: fix potential use after free in udp_v4_early_demux()
  macvtap: signal truncated packets
  tun: unbreak truncated packet signalling
  net: sched: htb: fix the calculation of quantum
  net: sched: tbf: fix the calculation of max_size
  micrel: add support for KSZ8041RNLI
  ...

Pull x86 fixes from Peter Anvin:
 "This is a pretty small batch:

  The biggest single change is to stop using EFI time services on 32-bit
  platforms.  This matches our current behavior on 64-bit platforms as
  we already had ruled them out there as being too unreliable.  Turns
  out that affects 32-bit platforms, too.

  One NULL pointer fix for SGI UV.

  Two minor build fixes, one of which only affects icc and the other
  which affects icc and future versions or nonstandard default settings
  of gcc"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Don't use (U)EFI time services on 32 bit
  x86, build, icc: Remove uninitialized_var() from compiler-intel.h
  x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used
  x86, build: Pass in additional -mno-mmx, -mno-sse options

Pull PCI updates from Bjorn Helgaas:
 "PCI device hotplug
    - Move device_del() from pci_stop_dev() to pci_destroy_dev() (Rafael
      Wysocki)

  Host bridge drivers
    - Update maintainers for DesignWare, i.MX6, Armada, R-Car (Bjorn
      Helgaas)
    - mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin
      (Jason Gunthorpe)

  Miscellaneous
    - Avoid unnecessary CPU switch when calling .probe() (Alexander
      Duyck)
    - Revert "workqueue: allow work_on_cpu() to be called recursively"
      (Bjorn Helgaas)
    - Disable Bus Master only on kexec reboot (Khalid Aziz)
    - Omit PCI ID macro strings to shorten quirk names for LTO (Michal
      Marek)"

* tag 'pci-v3.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  MAINTAINERS: Add DesignWare, i.MX6, Armada, R-Car PCI host maintainers
  PCI: Disable Bus Master only on kexec reboot
  PCI: mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin
  PCI: Omit PCI ID macro strings to shorten quirk names
  PCI: Move device_del() from pci_stop_dev() to pci_destroy_dev()
  Revert "workqueue: allow work_on_cpu() to be called recursively"
  PCI: Avoid unnecessary CPU switch when calling driver .probe() method

Pull SELinux fixes from James Morris.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute()
  selinux: look for IPsec labels on both inbound and outbound packets
  selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute()
  selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output()
  selinux: fix possible memory leak

This reverts commit 102aefdd.

Tom London reports that it causes sync() to hang on Fedora rawhide:

  https://bugzilla.redhat.com/show_bug.cgi?id=1033965

and Josh Boyer bisected it down to this commit.  Reverting the commit in
the rawhide kernel fixes the problem.

Eric Paris root-caused it to incorrect subtype matching in that commit
breaking fuse, and has a tentative patch, but by now we're better off
retrying this in 3.14 rather than playing with it any more.
Reported-by: NTom London <selinux@gmail.com>
Bisected-by: NJosh Boyer <jwboyer@fedoraproject.org>
Acked-by: NEric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Anand Avati <avati@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch changes the igb_phy_has_link function to check the value of the
parameter before deciding to use udelay or mdelay in order to be sure that
the value is not too high for udelay function.

CC: stable kernel <stable@vger.kernel.org> # 3.9+
Signed-off-by: NSunil K Pandey <sunil.k.pandey@intel.com>
Signed-off-by: NKevin B Smith <kevin.b.smith@intel.com>
Signed-off-by: NCarolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the vsi->tx_rings structure is NULL we don't want to panic.

Change-Id: Ic694f043701738c434e8ebe0caf0673f4410dc10
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NKavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull EDAC fix from Borislav Petkov:
 "Silence a compiler warning in sb_edac"

* tag 'edac_fixes_for_3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  sb_edac: Shut up compiler warning when EDAC_DEBUG is enabled

Pull ARM fixes from Russell King:
 "This resolves some further issues with the dma mask changes on ARM
  which have been found by TI and others, and also some corner cases
  with the updates to the virtual to physical address translations.

  Konstantin also found some problems with the unwinder, which now
  performs tighter verification that the stack is valid while unwinding"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: fix asm/memory.h build error
  ARM: 7917/1: cacheflush: correctly limit range of memory region being flushed
  ARM: 7913/1: fix framepointer check in unwind_frame
  ARM: 7912/1: check stack pointer in get_wchan
  ARM: 7909/1: mm: Call setup_dma_zone() post early_paging_init()
  ARM: 7908/1: mm: Fix the arm_dma_limit calculation
  ARM: another fix for the DMA mapping checks

Pull ARC fixes from Vineet Gupta:
 "These are couple of weeks old already, but I just couldn't get them to
  you earlier.

   - couple of fixes for recently added perf code
   - build time extable sort"

* tag 'arc-fixes-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [perf] Fix a few thinkos
  ARC: Add guard macro to uapi/asm/unistd.h
  ARC: extable: Enable sorting at build time

Pull device mapper fixes from Mike Snitzer:
 "A set of device-mapper fixes for 3.13.

  A fix for possible memory corruption during DM table load, fix a
  possible leak of snapshot space in case of a crash, fix a possible
  deadlock due to a shared workqueue in the delay target, fix to
  initialize read-only module parameters that are used to export metrics
  for dm stats and dm bufio.

  Quite a few stable fixes were identified for both the thin-
  provisioning and caching targets as a result of increased regression
  testing using the device-mapper-test-suite (dmts).  The most notable
  of these are the reference counting fixes for the space map btree that
  is used by the dm-array interface -- without these the dm-cache
  metadata will leak, resulting in dm-cache devices running out of
  metadata blocks.  Also, some important fixes related to the
  thin-provisioning target's transition to read-only mode on error"

* tag 'dm-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm array: fix a reference counting bug in shadow_ablock
  dm space map: disallow decrementing a reference count below zero
  dm stats: initialize read-only module parameter
  dm bufio: initialize read-only module parameters
  dm cache: actually resize cache
  dm cache: update Documentation for invalidate_cblocks's range syntax
  dm cache policy mq: fix promotions to occur as expected
  dm thin: allow pool in read-only mode to transition to read-write mode
  dm thin: re-establish read-only state when switching to fail mode
  dm thin: always fallback the pool mode if commit fails
  dm thin: switch to read-only mode if metadata space is exhausted
  dm thin: switch to read only mode if a mapping insert fails
  dm space map metadata: return on failure in sm_metadata_new_block
  dm table: fail dm_table_create on dm_round_up overflow
  dm snapshot: avoid snapshot space leak on crash
  dm delay: fix a possible deadlock due to shared workqueue

Pull HID fixes from Jiri Kosina:

 - Genius Gx Imperator Keyboard regression fix (missing break in case),
   by Ben Hutchings

 - duplicate sysfs entry error fix for hid-sensor-hub driver, by
   Srinivas Pandruvada

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: hid-sensor-hub: fix duplicate sysfs entry error
  HID: kye: Fix missing break in kye_report_fixup()

Jason Gunthorpe reports a build failure when ARM_PATCH_PHYS_VIRT is
not defined:

In file included from arch/arm/include/asm/page.h:163:0,
                 from include/linux/mm_types.h:16,
                 from include/linux/sched.h:24,
                 from arch/arm/kernel/asm-offsets.c:13:
arch/arm/include/asm/memory.h: In function '__virt_to_phys':
arch/arm/include/asm/memory.h:244:40: error: 'PHYS_OFFSET' undeclared (first use in this function)
arch/arm/include/asm/memory.h:244:40: note: each undeclared identifier is reported only once for each function it appears in
arch/arm/include/asm/memory.h: In function '__phys_to_virt':
arch/arm/include/asm/memory.h:249:13: error: 'PHYS_OFFSET' undeclared (first use in this function)

Fixes: ca5a45c0 ("ARM: mm: use phys_addr_t appropriately in p2v and v2p conversions")
Tested-By: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Pull regulator fixes from Mark Brown:
 "A small set of driver fixes plus one larger core change which changes
  the way we check to see if we're using DT so that there aren't any
  races between deciding we're using DT and the regulator subsystem
  noticing.

  This makes the new support for substituting a dummy regulator and
  optional regulators work a lot better on DT systems since it ensures
  that we don't trigger probe deferral when we shouldn't which was
  causing bugs in clients"

* tag 'regulator-v3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: pfuze100: allow misprogrammed ID
  regulator: pfuze100: Fix address of FABID
  regulator: as3722: set the correct current limit
  regulator: core: Check for DT every time we check full constraints
  regulator: core: Replace checks of have_full_constraints with a function

Pull regmap fixes from Mark Brown:
 "Two small changes to fix some error handling and checking (both of
  which would be quite serious if the errors trigger) plus a trivial
  documentation fix"

* tag 'regmap-v3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: use IS_ERR() to check clk_get() results
  regmap: make sure we unlock on failure in regmap_bulk_write
  regmap: trivial comment fix (copy'n'paste error)

Pull i2c fixes from Wolfram Sang:
 "Here are two simple but wanted fixes for the i2c subsystem"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: imx: Check the return value from clk_prepare_enable()
  i2c: mux: Inherit retry count and timeout from parent for muxed bus

Pull MTD fixes from Brian Norris:
 "Two MTD fixes, for the pxa3xx-nand driver:

   - This driver was not ready to fully Armada 370 NAND, with
     particularly notable problems seen on flash with 2KB page sizes.
     This "compatible" entry really should have been held back until
     3.14 or later.

   - Fix a bug seen in rare cases on the error path of a failed probe
     attempt, where we free unallocated DMA resources"

* tag 'for-linus-20131212' of git://git.infradead.org/linux-mtd:
  mtd: nand: pxa3xx: Use info->use_dma to release DMA resources
  Partially revert "mtd: nand: pxa3xx: Introduce 'marvell,armada370-nand' compatible string"

Pull slave-dmaengine fixes from Vinod Koul:
 "Here is the common fixes PULL for dmaengine.

  Dan has been working on fixing the build issues in bunch of drivers.
  Here we have one fixing s3c24xx-dma, along with fix from Russell on
  pl08x.  Also we have Kuninori rcar dma fixes.  The s3c24xx-dma which
  was added in last merge window missed updates to usage of DMA_COMPLETE
  so converting the last driver"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dma: fix build breakage in s3c24xx-dma
  Fix pl08x warnings
  rcar-hpbdma: initialise plane information when halted
  rcar-hpbdma: fixup channel busy check for double plane
  rcar-hpbdma: add max transfer size
  dma: mmp_pdma: add missing platform_set_drvdata() in mmp_pdma_probe()
  dmaengine: s3c24xx-dma: use DMA_COMPLETE for dma completion status

An old array block could have its reference count decremented below
zero when it is being replaced in the btree by a new array block.

The fix is to increment the old ablock's reference count just before
inserting a new ablock into the btree.
Signed-off-by: NJoe Thornber <ejt@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+

The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063e ("dm space map: optimise
sm_ll_dec and sm_ll_inc").  To fix this regression we return an error
code from the mutator function pointer passed to sm_ll_mutate() and have
dec_ref_count() return -EINVAL if the old ref_count is 0.

Add a DMERR to reflect the potential seriousness of this error.

Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path.

With this fix the following dmts regression test now passes:
 dmtest run --suite cache -n /metadata_use_kernel/

The next patch fixes the higher-level dm-array code that exposed this
regression.
Signed-off-by: NJoe Thornber <ejt@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.12+

Merge patches from Andrew Morton:
  "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: memcg: do not allow task about to OOM kill to bypass the limit
  mm: memcg: fix race condition between memcg teardown and swapin
  thp: move preallocated PTE page table on move_huge_pmd()
  mfd/rtc: s5m: fix register updating by adding regmap for RTC
  rtc: s5m: enable IRQ wake during suspend
  rtc: s5m: limit endless loop waiting for register update
  rtc: s5m: fix unsuccesful IRQ request during probe
  drivers/rtc/rtc-s5m.c: fix info->rtc assignment
  include/linux/kernel.h: make might_fault() a nop for !MMU
  drivers/rtc/rtc-at91rm9200.c: correct alarm over day/month wrap
  procfs: also fix proc_reg_get_unmapped_area() for !MMU case
  mm: memcg: do not declare OOM from __GFP_NOFAIL allocations
  include/linux/hugetlb.h: make isolate_huge_page() an inline

Commit 49426420 ("mm: memcg: handle non-error OOM situations more
gracefully") allowed tasks that already entered a memcg OOM condition to
bypass the memcg limit on subsequent allocation attempts hoping this
would expedite finishing the page fault and executing the kill.

David Rientjes is worried that this breaks memcg isolation guarantees
and since there is no evidence that the bypass actually speeds up fault
processing just change it so that these subsequent charge attempts fail
outright.  The notable exception being __GFP_NOFAIL charges which are
required to bypass the limit regardless.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-bt: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a race condition between a memcg being torn down and a swapin
triggered from a different memcg of a page that was recorded to belong
to the exiting memcg on swapout (with CONFIG_MEMCG_SWAP extension).  The
result is unreclaimable pages pointing to dead memcgs, which can lead to
anything from endless loops in later memcg teardown (the page is charged
to all hierarchical parents but is not on any LRU list) or crashes from
following the dangling memcg pointer.

Memcgs with tasks in them can not be torn down and usually charges don't
show up in memcgs without tasks.  Swapin with the CONFIG_MEMCG_SWAP
extension is the notable exception because it charges the cgroup that
was recorded as owner during swapout, which may be empty and in the
process of being torn down when a task in another memcg triggers the
swapin:

  teardown:                 swapin:

                            lookup_swap_cgroup_id()
                            rcu_read_lock()
                            mem_cgroup_lookup()
                            css_tryget()
                            rcu_read_unlock()
  disable css_tryget()
  call_rcu()
    offline_css()
      reparent_charges()
                            res_counter_charge() (hierarchical!)
                            css_put()
                              css_free()
                            pc->mem_cgroup = dead memcg
                            add page to dead lru

Add a final reparenting step into css_free() to make sure any such raced
charges are moved out of the memcg before it's finally freed.

In the longer term it would be cleaner to have the css_tryget() and the
res_counter charge under the same RCU lock section so that the charge
reparenting is deferred until the last charge whose tryget succeeded is
visible.  But this will require more invasive changes that will be
harder to evaluate and backport into stable, so better defer them to a
separate change set.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrey Wagin reported crash on VM_BUG_ON() in pgtable_pmd_page_dtor() with
fallowing backtrace:

  free_pgd_range+0x2bf/0x410
  free_pgtables+0xce/0x120
  unmap_region+0xe0/0x120
  do_munmap+0x249/0x360
  move_vma+0x144/0x270
  SyS_mremap+0x3b9/0x510
  system_call_fastpath+0x16/0x1b

The crash can be reproduce with this test case:

  #define _GNU_SOURCE
  #include <sys/mman.h>
  #include <stdio.h>
  #include <unistd.h>

  #define MB (1024 * 1024UL)
  #define GB (1024 * MB)

  int main(int argc, char **argv)
  {
	char *p;
	int i;

	p = mmap((void *) GB, 10 * MB, PROT_READ | PROT_WRITE,
			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
	for (i = 0; i < 10 * MB; i += 4096)
		p[i] = 1;
	mremap(p, 10 * MB, 10 * MB, MREMAP_FIXED | MREMAP_MAYMOVE, 2 * GB);
	return 0;
  }

Due to split PMD lock, we now store preallocated PTE tables for THP
pages per-PMD table.  It means we need to move them to other PMD table
if huge PMD moved there.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: NAndrey Vagin <avagin@openvz.org>
Tested-by: NAndrey Vagin <avagin@openvz.org>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>