No need to always allocate the theoretical maximum here.
Signed-off-by: NChristian König <christian.koenig@amd.com>

It hangs the hardware.
Signed-off-by: NMarek Olšák <marek.olsak@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org

Signed-off-by: NChristian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org

Let's be conservative and use 100 here until we find something better.

Bugs: https://bugzilla.kernel.org/show_bug.cgi?id=75241Signed-off-by: NChristian König <christian.koenig@amd.com>

Fixes from Chris, all cc: stable.

* tag 'drm-intel-fixes-2014-05-27' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Prevent negative relocation deltas from wrapping
  drm/i915: Only copy back the modified fields to userspace from execbuffer
  drm/i915: Fix dynamic allocation of physical handles

This is pure evil. Userspace, I'm looking at you SNA, repacks batch
buffers on the fly after generation as they are being passed to the
kernel for execution. These batches also contain self-referenced
relocations as a single buffer encompasses the state commands, kernels,
vertices and sampler. During generation the buffers are placed at known
offsets within the full batch, and then the relocation deltas (as passed
to the kernel) are tweaked as the batch is repacked into a smaller buffer.
This means that userspace is passing negative relocations deltas, which
subsequently wrap to large values if the batch is at a low address. The
GPU hangs when it then tries to use the large value as a base for its
address offsets, rather than wrapping back to the real value (as one
would hope). As the GPU uses positive offsets from the base, we can
treat the relocation address as the minimum address read by the GPU.
For the upper bound, we trust that userspace will not read beyond the
end of the buffer.

So, how do we fix negative relocations from wrapping? We can either
check that every relocation looks valid when we write it, and then
position each object such that we prevent the offset wraparound, or we
just special-case the self-referential behaviour of SNA and force all
batches to be above 256k. Daniel prefers the latter approach.

This fixes a GPU hang when it tries to use an address (relocation +
offset) greater than the GTT size. The issue would occur quite easily
with full-ppgtt as each fd gets its own VM space, so low offsets would
often be handed out. However, with the rearrangement of the low GTT due
to capturing the BIOS framebuffer, it is already affecting kernels 3.15
onwards. I think only IVB+ is susceptible to this bug, but the workaround
should only kick in rarely, so it seems sensible to always apply it.

v3: Use a bias for batch buffers to prevent small negative delta relocations
from wrapping.

v4 from Daniel:
- s/BIAS/BATCH_OFFSET_BIAS/
- Extract eb_vma_misplaced/i915_vma_misplaced since the conditions
  were growing rather cumbersome.
- Add a comment to eb_get_batch explaining why we do this.
- Apply the batch offset bias everywhere but mention that we've only
  observed it on gen7 gpus.
- Drop PIN_OFFSET_FIX for now, that slipped in from a feature patch.

v5: Add static to eb_get_batch, spotted by 0-day tester.

Testcase: igt/gem_bad_reloc
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78533
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We only want to modifiy a single field in the userspace view of the
execbuffer command buffer, so explicitly change that rather than copy
everything back again.

This serves two purposes:

1. The single fields are much cheaper to copy (constant size so the
copy uses special case code) and much smaller than the whole array.

2. We modify the array for internal use that need to be masked from
the user.

Note: We need this backported since without it the next bugfix will
blow up when userspace recycles batchbuffers and relocations.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A single object may be referenced by multiple registers fundamentally
breaking the static allotment of ids in the current design. When the
object is used the second time, the physical address of the first
assignment is relinquished and a second one granted. However, the
hardware is still reading (and possibly writing) to the old physical
address now returned to the system. Eventually hilarity will ensue, but
in the short term, it just means that cursors are broken when using more
than one pipe.

v2: Fix up leak of pci handle when handling an error during attachment,
and avoid a double kmap/kunmap. (Ville)
Rebase against -fixes.

v3: And fix the error handling added in v2 (Ville)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77351Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull AFS fixes and cleanups from David Howells:
 "Here are some patches to the AFS filesystem:

  1) Fix problems in the clean-up parts of the cache manager service
     handler.

  2) Split afs_end_call() introduced in (1) and replace some identical
     code elsewhere with a call to the first half of the split function.

  3) Fix an error introduced in the workqueue PREPARE_WORK() elimination
     commits.

  4) Clean up argument passing to functions called from the workqueue as
     there's now an insulating layer between them and the workqueue.
     This is possible from (3)"

* 'afs' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  AFS: Pass an afs_call* to call->async_workfn() instead of a work_struct*
  AFS: Fix kafs module unloading
  AFS: Part of afs_end_call() is identical to code elsewhere, so split it
  AFS: Fix cache manager service handlers

Merge documentation fixes from Randy Dunlap.

* emailed patches from Randy Dunlap <rdunlap@infradead.org>:
  Documentation: update /proc/stat "intr" count summary
  Documentation: update java sample wrapper for java 7
  Documentation: update thunderbird email client settings
  Documentation: fix typos in drm docbook

The sum at the beginning of line "intr" includes also unnumbered
interrupts.  It implies that the sum at the beginning isn't the sum
of the remainder of the line, not even an estimation.

Fixed the documentation to mention that.

This behaviour was added to /proc/stat in commit a2eddfa9 ("x86:
make /proc/stat account for all interrupts")
Signed-off-by: NJan Moskyto Matejka <mq@suse.cz>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The sample wrapper currently fails on some Java 7 .class files.  This
updates the wrapper to properly handle those files.
Signed-off-by: NJonathan Callen <jcallen@gentoo.org>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Added setting to email-clients that is easier to read and is easier to
setup thunderbird.  Removed config settings and added GUI settings.
Signed-off-by: NPaul McQuade <paulmcquad@gmail.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix spelling typo in DocBook/drm.tmpl
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull hwmon subsystem fixes from Jean Delvare.

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (ntc_thermistor) Fix OF device ID mapping
  hwmon: (ntc_thermistor) Fix dependencies
  hwmon: Document temp[1-*]_min_hyst sysfs attribute

Pull single scsi fix from James Bottomley:
 "This is a single fix for a bug exposed by a sysfs change in 3.13 which
  now causes libsas to trigger a warn on in device removal"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] scsi_transport_sas: move bsg destructor into sas_rphy_remove

Pull two nfsd bugfixes from Bruce Fields:
 "Just two bugfixes, one for a merge-window-introduced ACL regression,
  the other for a longer-standing v4 state bug"

* 'for-3.15' of git://linux-nfs.org/~bfields/linux:
  nfsd4: warn on finding lockowner without stateid's
  nfsd4: remove lockowner when removing lock stateid
  nfsd4: fix corruption on setting an ACL.

The mapping from OF device IDs to platform device IDs is wrong.
TYPE_NCPXXWB473 is 0, TYPE_NCPXXWL333 is 1, so
ntc_thermistor_id[TYPE_NCPXXWB473] is { "ncp15wb473", TYPE_NCPXXWB473 }
while
ntc_thermistor_id[TYPE_NCPXXWL333] is { "ncp18wb473", TYPE_NCPXXWB473 }.

So the name is wrong for all but the "ntc,ncp15wb473" entry, and the
type is wrong for the "ntc,ncp15wl333" entry.

So map the entries by index, it is neither elegant nor robust but at
least it is correct.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Fixes: 9e8269de hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>

In commit 9e8269de, support was added for ntc_thermistor devices being
declared in the device tree and implemented on top of IIO. With that
change, a dependency was added to the ntc_thermistor driver:

	depends on (!OF && !IIO) || (OF && IIO)

This construct has the drawback that the driver can no longer be
selected when OF is set and IIO isn't, nor when IIO is set and OF is
not. This is a regression for the original users of the driver.

As the new code depends on IIO and is useless without OF, include it
only if both are enabled, and set the dependencies accordingly. This
is clearer, more simple and more correct.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Fixes: 9e8269de hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Cc: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>

The temp[1-*]_min_hyst sysfs attribute is already implemented by 3
hwmon drivers (adt7x10, lm77 and lm92) but was missing from the
standard interface.

Also add temp[1-*]_lcrit_hyst for consistency, even though no driver
implement that one for the time being.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>

Merge tag 'dmaengine-fixes-3.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine

Pull dmaengine fixes from Dan Williams:
 "Two fixes for -stable:

   - async_mult() sometimes maps less buffers than initially requested.
      We end up freeing dmaengine_unmap_data on an invalid pool.

   - mv_xor: register write ordering fix"

* tag 'dmaengine-fixes-3.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine:
  dmaengine: fix dmaengine_unmap failure
  dma: mv_xor: Flush descriptors before activating a channel

Pull sparc fixes from David Miller:
 "A small bunch of bug fixes, in particular:

   1) On older cpus we need a different chunk of virtual address space
      to map the huge page TSB.

   2) Missing memory barrier in Niagara2 memcpy.

   3) trinity showed some places where fault validation was
      unnecessarily loud on sparc64

   4) Some sysfs printf's need a type adjustment, from Toralf Förster"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: fix format string mismatch in arch/sparc/kernel/sysfs.c
  sparc64: Add membar to Niagara2 memcpy code.
  sparc64: Fix huge TSB mapping on pre-UltraSPARC-III cpus.
  sparc64: Don't bark so loudly about 32-bit tasks generating 64-bit fault addresses.

Pull networking fixes from David Miller:
 "It looks like a sizeble collection but this is nearly 3 weeks of bug
  fixing while you were away.

   1) Fix crashes over IPSEC tunnels with NAT, the latter can reroute
      the packet through a non-IPSEC protected path and the code has to
      be able to handle SKBs attached to routes lacking an attached xfrm
      state.  From Steffen Klassert.

   2) Fix OOPSs in ipv4 and ipv6 ipsec layers for unsupported
      sub-protocols, also from Steffen Klassert.

   3) Set local_df on fragmented netfilter skbs otherwise we won't be
      able to forward successfully, from Florian Westphal.

   4) cdc_mbim ipv6 neighbour code does __vlan_find_dev_deep without
      holding RCU lock, from Bjorn Mork.

   5) local_df test in ip_may_fragment is inverted, from Florian
      Westphal.

   6) jme driver doesn't check for DMA mapping failures, from Neil
      Horman.

   7) qlogic driver doesn't calculate number of TX queues properly, from
      Shahed Shaikh.

   8) fib_info_cnt can drift irreversibly positive if we fail to
      allocate the fi->fib_metrics array, from Sergey Popovich.

   9) Fix use after free in ip6_route_me_harder(), also from Sergey
      Popovich.

  10) When SYSCTL is disabled, we don't handle local_port_range and
      ping_group_range defaults properly at all, from Cong Wang.

  11) Unaccelerated VLAN tagged frames improperly handled by cdc_mbim
      driver, fix from Bjorn Mork.

  12) cassini driver needs nested lock annotations for TX locking, from
      Emil Goode.

  13) On init error ipv6 VTI driver can unregister pernet ops twice,
      oops.  Fix from Mahtias Krause.

  14) If macvlan device is down, don't propagate IFF_ALLMULTI changes,
      from Peter Christensen.

  15) Missing NULL pointer check while parsing netlink config options in
      ip6_tnl_validate().  From Susant Sahani.

  16) Fix handling of neighbour entries during ipv6 router reachability
      probing, from Duan Jiong.

  17) x86 and s390 JIT address randomization has some address
      calculation bugs leading to crashes, from Alexei Starovoitov and
      Heiko Carstens.

  18) Clear up those uglies with nop patching and net_get_random_once(),
      from Hannes Frederic Sowa.

  19) Option length miscalculated in ip6_append_data(), fix also from
      Hannes Frederic Sowa.

  20) A while ago we fixed a race during device unregistry when a
      namespace went down, turns out there is a second place that needs
      similar protection.  From Cong Wang.

  21) In the new Altera TSE driver multicast filtering isn't working,
      disable it and just use promisc mode until the cause is found.
      From Vince Bridgers.

  22) When we disable router enabling in ipv6 we have to flush the
      cached routes explicitly, from Duan Jiong.

  23) NBMA tunnels should not cache routes on the tunnel object because
      the key is variable, from Timo Teräs.

  24) With stacked devices GRO information in skb->cb[] can be not setup
      properly, make sure it is in all code paths.  From Eric Dumazet.

  25) Really fix stacked vlan locking, multiple levels of nesting with
      intervening non-vlan devices are possible.  From Vlad Yasevich.

  26) Fallback ipip tunnel device's mtu is not setup properly, from
      Steffen Klassert.

  27) The packet scheduler's tcindex filter can crash because we
      structure copy objects with list_head's inside, oops.  From Cong
      Wang.

  28) Fix CHECKSUM_COMPLETE handling for ipv6 GRE tunnels, from Eric
      Dumazet.

  29) In some configurations 'itag' in __mkroute_input() can end up
      being used uninitialized because of how fib_validate_source()
      works.  Fix it by explitly initializing itag to zero like all the
      other fib_validate_source() callers do, from Li RongQing"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
  batman: fix a bogus warning from batadv_is_on_batman_iface()
  ipv4: initialise the itag variable in __mkroute_input
  bonding: Send ALB learning packets using the right source
  bonding: Don't assume 802.1Q when sending alb learning packets.
  net: doc: Update references to skb->rxhash
  stmmac: Remove unbalanced clk_disable call
  ipv6: gro: fix CHECKSUM_COMPLETE support
  net_sched: fix an oops in tcindex filter
  can: peak_pci: prevent use after free at netdev removal
  ip_tunnel: Initialize the fallback device properly
  vlan: Fix build error wth vlan_get_encap_level()
  can: c_can: remove obsolete STRICT_FRAME_ORDERING Kconfig option
  MAINTAINERS: Pravin Shelar is Open vSwitch maintainer.
  bnx2x: Convert return 0 to return rc
  bonding: Fix alb mode to only use first level vlans.
  bonding: Fix stacked device detection in arp monitoring
  macvlan: Fix lockdep warnings with stacked macvlan devices
  vlan: Fix lockdep warning with stacked vlan devices.
  net: Allow for more then a single subclass for netif_addr_lock
  net: Find the nesting level of a given device by type.
  ...

Pull scheduler fixes from Ingo Molnar:
 "The biggest commit is an irqtime accounting loop latency fix, the rest
  are misc fixes all over the place: deadline scheduling, docs, numa,
  balancer and a bad to-idle latency fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/numa: Initialize newidle balance stats in sd_numa_init()
  sched: Fix updating rq->max_idle_balance_cost and rq->next_balance in idle_balance()
  sched: Skip double execution of pick_next_task_fair()
  sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check
  sched/deadline: Fix memory leak
  sched/deadline: Fix sched_yield() behavior
  sched: Sanitize irq accounting madness
  sched/docbook: Fix 'make htmldocs' warnings caused by missing description

Pull perf fixes from Ingo Molnar:
 "The biggest changes are fixes for races that kept triggering Trinity
  crashes, plus liblockdep build fixes and smaller misc fixes.

  The liblockdep bits in perf/urgent are a pull mistake - they should
  have been in locking/urgent - but by the time I noticed other commits
  were added and testing was done :-/ Sorry about that"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()
  perf: Prevent false warning in perf_swevent_add
  perf: Limit perf_event_attr::sample_period to 63 bits
  tools/liblockdep: Remove all build files when doing make clean
  tools/liblockdep: Build liblockdep from tools/Makefile
  perf/x86/intel: Fix Silvermont's event constraints
  perf: Fix perf_event_init_context()
  perf: Fix race in removing an event

Pull drm radeon and nouveau fixes from Dave Airlie:
 "Fixes for the other big two.

  The radeon VCE one is large but it fixes some userspace triggerable
  issues, otherwise its blackscreens and oopses.

  Nouveau fixes a bleeding laptop panel issue when displayport is used
  sometimes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/pm: don't allow debugfs/sysfs access when PX card is off (v2)
  drm/radeon: avoid segfault on device open when accel is not working.
  drm/radeon: fix typo in finding PLL params
  drm/radeon: fix register typo on si
  drm/radeon: fix buffer placement under memory pressure v2
  drm/radeon: fix page directory update size estimation
  drm/radeon: handle non-VGA class pci devices with ATRM
  drm/radeon: fix DCE83 check for mullins
  drm/radeon: check VCE relocation buffer range v3
  drm/radeon: also try GART for CPU accessed buffers
  drm/gf119-/disp: fix nasty bug which can clobber SOR0's clock setup
  drm/nvd9/therm: handle another kind of PWM fan

Merge misc fixes from Andrew Morton:
 "9 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  MAINTAINERS: add closing angle bracket to Vince Bridgers' email address
  Documentation: fix DOCBOOKS=... building
  ocfs2: fix double kmem_cache_destroy in dlm_init
  mm/memory-failure.c: fix memory leak by race between poison and unpoison
  wait: swap EXIT_ZOMBIE(Z) and EXIT_DEAD(X) chars in TASK_STATE_TO_CHAR_STR
  memcg: fix swapcache charge from kernel thread context
  mm: madvise: fix MADV_WILLNEED on shmem swapouts
  mm/filemap.c: avoid always dirtying mapping->flags on O_DIRECT
  hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage

Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Vince Bridgers <vbridgers2013@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prior to commit 42661299 ("[media] DocBook: Move all media docbook
stuff into its own directory") it was possible to build only a single
(or more) book(s) by calling, for example

    make htmldocs DOCBOOKS=80211.xml

This now fails:

    cp: target `.../Documentation/DocBook//media_api' is not a directory

Ignore errors from that copy to make this possible again.

Fixes: 42661299 ("[media] DocBook: Move all media docbook stuff into its own directory")
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In dlm_init, if create dlm_lockname_cache failed in
dlm_init_master_caches, it will destroy dlm_lockres_cache which created
before twice.  And this will cause system die when loading modules.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a memory error happens on an in-use page or (free and in-use)
hugepage, the victim page is isolated with its refcount set to one.

When you try to unpoison it later, unpoison_memory() calls put_page()
for it twice in order to bring the page back to free page pool (buddy or
free hugepage list).  However, if another memory error occurs on the
page which we are unpoisoning, memory_failure() returns without
releasing the refcount which was incremented in the same call at first,
which results in memory leak and unconsistent num_poisoned_pages
statistics.  This patch fixes it.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@vger.kernel.org>    [2.6.32+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit ad86622b ("wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide
EXIT_TRACE from user-space") the order of task state definitions were
changed: EXIT_DEAD and EXIT_ZOMBIE were swapped.  Though the charterers
for the states in TASK_STATE_TO_CHAR_STR string were not updated.  This
patch synchronizes the string to the order of definitions.
Signed-off-by: NMasatake YAMATO <yamato@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 284f39af ("mm: memcg: push !mm handling out to page cache
charge function") explicitly checks for page cache charges without any
mm context (from kernel thread context[1]).

This seemed to be the only possible case where memory could be charged
without mm context so commit 03583f1a ("memcg: remove unnecessary
!mm check from try_get_mem_cgroup_from_mm()") removed the mm check from
get_mem_cgroup_from_mm().  This however caused another NULL ptr
dereference during early boot when loopback kernel thread splices to
tmpfs as reported by Stephan Kulow:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000360
  IP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Oops: 0000 [#1] SMP
  Modules linked in: btrfs dm_multipath dm_mod scsi_dh multipath raid10 raid456 async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod parport_pc parport nls_utf8 isofs usb_storage iscsi_ibft iscsi_boot_sysfs arc4 ecb fan thermal nfs lockd fscache nls_iso8859_1 nls_cp437 sg st hid_generic usbhid af_packet sunrpc sr_mod cdrom ata_generic uhci_hcd virtio_net virtio_blk ehci_hcd usbcore ata_piix floppy processor button usb_common virtio_pci virtio_ring virtio edd squashfs loop ppa]
  CPU: 0 PID: 97 Comm: loop1 Not tainted 3.15.0-rc5-5-default #1
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x40/0xe0
    mem_cgroup_charge_file+0x8b/0xd0
    shmem_getpage_gfp+0x66b/0x7b0
    shmem_file_splice_read+0x18f/0x430
    splice_direct_to_actor+0xa2/0x1c0
    do_lo_receive+0x5a/0x60 [loop]
    loop_thread+0x298/0x720 [loop]
    kthread+0xc6/0xe0
    ret_from_fork+0x7c/0xb0

Also Branimir Maksimovic reported the following oops which is tiggered
for the swapcache charge path from the accounting code for kernel threads:

  CPU: 1 PID: 160 Comm: kworker/u8:5 Tainted: P           OE 3.15.0-rc5-core2-custom #159
  Hardware name: System manufacturer System Product Name/MAXIMUSV GENE, BIOS 1903 08/19/2013
  task: ffff880404e349b0 ti: ffff88040486a000 task.ti: ffff88040486a000
  RIP: get_mem_cgroup_from_mm.isra.42+0x2b/0x60
  Call Trace:
    __mem_cgroup_try_charge_swapin+0x45/0xf0
    mem_cgroup_charge_file+0x9c/0xe0
    shmem_getpage_gfp+0x62c/0x770
    shmem_write_begin+0x38/0x40
    generic_perform_write+0xc5/0x1c0
    __generic_file_aio_write+0x1d1/0x3f0
    generic_file_aio_write+0x4f/0xc0
    do_sync_write+0x5a/0x90
    do_acct_process+0x4b1/0x550
    acct_process+0x6d/0xa0
    do_exit+0x827/0xa70
    kthread+0xc3/0xf0

This patch fixes the issue by reintroducing mm check into
get_mem_cgroup_from_mm.  We could do the same trick in
__mem_cgroup_try_charge_swapin as we do for the regular page cache path
but it is not worth troubles.  The check is not that expensive and it is
better to have get_mem_cgroup_from_mm more robust.

[1] - http://marc.info/?l=linux-mm&m=139463617808941&w=2

Fixes: 03583f1a ("memcg: remove unnecessary !mm check from try_get_mem_cgroup_from_mm()")
Reported-and-tested-by: NStephan Kulow <coolo@suse.com>
Reported-by: NBranimir Maksimovic <branimir.maksimovic@gmail.com>
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

MADV_WILLNEED currently does not read swapped out shmem pages back in.

Commit 0cd6144a ("mm + fs: prepare for non-page entries in page
cache radix trees") made find_get_page() filter exceptional radix tree
entries but failed to convert all find_get_page() callers that WANT
exceptional entries over to find_get_entry().  One of them is shmem swap
readahead in madvise, which now skips over any swap-out records.

Convert it to find_get_entry().

Fixes: 0cd6144a ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In some testing I ran today (some fio jobs that spread over two nodes),
we end up spending 40% of the time in filemap_check_errors().  That
smells fishy.  Looking further, this is basically what happens:

blkdev_aio_read()
    generic_file_aio_read()
        filemap_write_and_wait_range()
            if (!mapping->nr_pages)
                filemap_check_errors()

and filemap_check_errors() always attempts two test_and_clear_bit() on
the mapping flags, thus dirtying it for every single invocation.  The
patch below tests each of these bits before clearing them, avoiding this
issue.  In my test case (4-socket box), performance went from 1.7M IOPS
to 4.0M IOPS.
Signed-off-by: NJens Axboe <axboe@fb.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For handling a free hugepage in memory failure, the race will happen if
another thread hwpoisoned this hugepage concurrently.  So we need to
check PageHWPoison instead of !PageHWPoison.

If hwpoison_filter(p) returns true or a race happens, then we need to
unlock_page(hpage).
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>	[2.6.36+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The 'renameat2()' system call was incorrectly added as a ENTRY_COMP() in
the parisc system call table by commit 18e480aa ("parisc: add
renameat2 syscall").  That causes a link-time error due to there not
being any compat version of that system call:

  arch/parisc/kernel/built-in.o: In function `sys_call_table':
  (.rodata+0xad0): undefined reference to `compat_sys_renameat2'
  make: *** [vmlinux] Error 1

Easily fixed by marking the system call as being the same for compat as
for native by using ENTRY_SAME() instead of ENTRY_COMP().
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

call->async_workfn() can take an afs_call* arg rather than a work_struct* as
the functions assigned there are now called from afs_async_workfn() which has
to call container_of() anyway.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NNathaniel Wesley Filardo <nwf@cs.jhu.edu>
Reviewed-by: NTejun Heo <tj@kernel.org>

At present, it is not possible to successfully unload the kafs module if there
are outstanding async outgoing calls (those made with afs_make_call()).  This
appears to be due to the changes introduced by:

	commit 05949945
	Author: Tejun Heo <tj@kernel.org>
	Date:   Fri Mar 7 10:24:50 2014 -0500
	Subject: afs: don't use PREPARE_WORK

which didn't go far enough.  The problem is due to:

 (1) The aforementioned commit introduced a separate handler function pointer
     in the call, call->async_workfn, in addition to the original workqueue
     item, call->async_work, for asynchronous operations because workqueues
     subsystem cannot handle the workqueue item pointer being changed whilst
     the item is queued or being processed.

 (2) afs_async_workfn() was introduced in that commit to be the callback for
     call->async_work.  Its sole purpose is to run whatever call->async_workfn
     points to.

 (3) call->async_workfn is only used from afs_async_workfn(), which is only
     set on async_work by afs_collect_incoming_call() - ie. for incoming
     calls.

 (4) call->async_workfn is *not* set by afs_make_call() when outgoing calls are
     made, and call->async_work is set afs_process_async_call() - and not
     afs_async_workfn().

 (5) afs_process_async_call() now changes call->async_workfn rather than
     call->async_work to point to afs_delete_async_call() to clean up, but this
     is only effective for incoming calls because call->async_work does not
     point to afs_async_workfn() for outgoing calls.

 (6) Because, for incoming calls, call->async_work remains pointing to
     afs_process_async_call() this results in an infinite loop.

Instead, make the workqueue uniformly vector through call->async_workfn, via
afs_async_workfn() and simply initialise call->async_workfn to point to
afs_process_async_call() in afs_make_call().
Signed-off-by: NNathaniel Wesley Filardo <nwf@cs.jhu.edu>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NTejun Heo <tj@kernel.org>