rcu_dereference_check_fdtable() looks very wrong,

1. rcu_my_thread_group_empty() was added by 844b9a87 "vfs: fix
   RCU-lockdep false positive due to /proc" but it doesn't really
   fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
   hit the same race with get_files_struct().

   And otoh rcu_my_thread_group_empty() can suppress the correct
   warning if the caller is the CLONE_FILES (without CLONE_THREAD)
   task.

2. files->count == 1 check is not really right too. Even if this
   files_struct is not shared it is not safe to access it lockless
   unless the caller is the owner.

   Otoh, this check is sub-optimal. files->count == 0 always means
   it is safe to use it lockless even if files != current->files,
   but put_files_struct() has to take rcu_read_lock(). See the next
   patch.

This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.

fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

it's never called with NULL argument...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

kill pointless method instances and don't bother with ->owner - it's
ignored for procfs files anyway, make use of remove_proc_subtree() for
removal, get rid of cell->proc_dir.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

pass owner explicitly to __register_nls(), make register_nls() a macro passing
THIS_MODULE as the owner argument to __register_nls().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* don't assume that ->dest_count won't change between copy_from_user()
and memdup_user()
* use fdget instead of fget
* don't bother comparing superblocks when we'd already compared vfsmounts
* get rid of excessive goto
* use file_inode() instead of open-coding the sucker
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* pass on-disk superblock to qnx4_chkroot() explicitly
* don't leave stale (and unused) pointers in qnx4_super_block
* free stuff in ->kill_sb(); ->put_super() becomes empty and dies
* simplify failure exits
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

simplifies failure exits in ->mount()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

failure exits are simpler that way
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and return saner errors from ->mount(), while we are at it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

don't bother open-coding it...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If ecryptfs_readlink_lower() fails, buf remains an uninitialized
pointer and passing it nd_set_link() won't do anything good.

Fixed by switching ecryptfs_readlink_lower() to saner API - make it
return buf or ERR_PTR(...) and update callers.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Since commit 61b365a5 ("drm/nouveau: populate master subdev pointer
only when fully constructed"), the nouveau_mxm(bios) call will return
NULL, since it's still being called from the constructor.  Instead, pass
the mxm pointer via the unused data field.

See https://bugs.freedesktop.org/show_bug.cgi?id=73791Reported-by: NAndreas Reis <andreas.reis@gmail.com>
Tested-by: NAndreas Reis <andreas.reis@gmail.com>
Signed-off-by: NIlia Mirkin <imirkin@alum.mit.edu>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull last-minute ACPI fix from Rafael Wysocki:
 "This reverts a commit that causes the Alan Cox' ASUS T100TA to "crash
  and burn" during boot if the Baytrail pinctrl driver is compiled in"

* tag 'acpi-3.13-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "ACPI: Add BayTrail SoC GPIO and LPSS ACPI IDs"

Pull perf fixes from Ingo Molnar:

 - an s2ram related fix on AMD systems

 - a perf fault handling bug that is relatively old but which has become
   much easier to trigger in v3.13 after commit e00b12e6 ("perf/x86:
   Further optimize copy_from_user_nmi()")

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/ibs: Fix waking up from S3 for AMD family 10h
  x86, mm, perf: Allow recursive faults from interrupts

This reverts commit f6308b36 (ACPI: Add BayTrail SoC GPIO and LPSS
ACPI IDs), because it causes the Alan Cox' ASUS T100TA to "crash and
burn" during boot if the Baytrail pinctrl driver is compiled in.

Fixes: f6308b36 (ACPI: Add BayTrail SoC GPIO and LPSS ACPI IDs)
Reported-by: NOne Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Requested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull networking fixes from David Miller:

 1) The value choosen for the new SO_MAX_PACING_RATE socket option on
    parisc was very poorly choosen, let's fix it while we still can.
    From Eric Dumazet.

 2) Our generic reciprocal divide was found to handle some edge cases
    incorrectly, part of this is encoded into the BPF as deep as the JIT
    engines themselves.  Just use a real divide throughout for now.
    From Eric Dumazet.

 3) Because the initial lookup is lockless, the TCP metrics engine can
    end up creating two entries for the same lookup key.  Fix this by
    doing a second lookup under the lock before we actually create the
    new entry.  From Christoph Paasch.

 4) Fix scatter-gather list init in usbnet driver, from Bjørn Mork.

 5) Fix unintended 32-bit truncation in cxgb4 driver's bit shifting.
    From Dan Carpenter.

 6) Netlink socket dumping uses the wrong socket state for timewait
    sockets.  Fix from Neal Cardwell.

 7) Fix netlink memory leak in ieee802154_add_iface(), from Christian
    Engelmayer.

 8) Multicast forwarding in ipv4 can overflow the per-rule reference
    counts, causing all multicast traffic to cease.  Fix from Hannes
    Frederic Sowa.

 9) via-rhine needs to stop all TX queues when it resets the device,
    from Richard Weinberger.

10) Fix RDS per-cpu accesses broken by the this_cpu_* conversions.  From
    Gerald Schaefer.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  s390/bpf,jit: fix 32 bit divisions, use unsigned divide instructions
  parisc: fix SO_MAX_PACING_RATE typo
  ipv6: simplify detection of first operational link-local address on interface
  tcp: metrics: Avoid duplicate entries with the same destination-IP
  net: rds: fix per-cpu helper usage
  e1000e: Fix compilation warning when !CONFIG_PM_SLEEP
  bpf: do not use reciprocal divide
  be2net: add dma_mapping_error() check for dma_map_page()
  bnx2x: Don't release PCI bars on shutdown
  net,via-rhine: Fix tx_timeout handling
  batman-adv: fix batman-adv header overhead calculation
  qlge: Fix vlan netdev features.
  net: avoid reference counter overflows on fib_rules in multicast forwarding
  dm9601: add USB IDs for new dm96xx variants
  MAINTAINERS: add virtio-dev ML for virtio
  ieee802154: Fix memory leak in ieee802154_add_iface()
  net: usbnet: fix SG initialisation
  inet_diag: fix inet_diag_dump_icsk() to use correct state for timewait sockets
  cxgb4: silence shift wrapping static checker warning

The s390 bpf jit compiler emits the signed divide instructions "dr" and "d"
for unsigned divisions.
This can cause problems: the dividend will be zero extended to a 64 bit value
and the divisor is the 32 bit signed value as specified A or X accumulator,
even though A and X are supposed to be treated as unsigned values.

The divide instrunctions will generate an exception if the result cannot be
expressed with a 32 bit signed value.
This is the case if e.g. the dividend is 0xffffffff and the divisor either 1
or also 0xffffffff (signed: -1).

To avoid all these issues simply use unsigned divide instructions.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SO_MAX_PACING_RATE definition on parisc got a typo.
Its not too late to fix it, before 3.13 is official.

Fixes: 62748f32 ("net: introduce SO_MAX_PACING_RATE")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 1ec047eb ("ipv6: introduce per-interface counter for
dad-completed ipv6 addresses") I build the detection of the first
operational link-local address much to complex. Additionally this code
now has a race condition.

Replace it with a much simpler variant, which just scans the address
list when duplicate address detection completes, to check if this is
the first valid link local address and send RS and MLD reports then.

Fixes: 1ec047eb ("ipv6: introduce per-interface counter for dad-completed ipv6 addresses")
Reported-by: NJiri Pirko <jiri@resnulli.us>
Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NFlavio Leitner <fbl@redhat.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because the tcp-metrics is an RCU-list, it may be that two
soft-interrupts are inside __tcp_get_metrics() for the same
destination-IP at the same time. If this destination-IP is not yet part of
the tcp-metrics, both soft-interrupts will end up in tcpm_new and create
a new entry for this IP.
So, we will have two tcp-metrics with the same destination-IP in the list.

This patch checks twice __tcp_get_metrics(). First without holding the
lock, then while holding the lock. The second one is there to confirm
that the entry has not been added by another soft-irq while waiting for
the spin-lock.

Fixes: 51c5d0c4 (tcp: Maintain dynamic metrics in local cache.)
Signed-off-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit ae4b46e9 "net: rds: use this_cpu_* per-cpu helper" broke per-cpu
handling for rds. chpfirst is the result of __this_cpu_read(), so it is
an absolute pointer and not __percpu. Therefore, __this_cpu_write()
should not operate on chpfirst, but rather on cache->percpu->first, just
like __this_cpu_read() did before.

Cc: <stable@vger.kernel.org> # 3.8+
Signed-off-byd Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull namespace fixes from Eric Biederman:
 "This is a set of 3 regression fixes.

  This fixes /proc/mounts when using "ip netns add <netns>" to display
  the actual mount point.

  This fixes a regression in clone that broke lxc-attach.

  This fixes a regression in the permission checks for mounting /proc
  that made proc unmountable if binfmt_misc was in use.  Oops.

  My apologies for sending this pull request so late.  Al Viro gave
  interesting review comments about the d_path fix that I wanted to
  address in detail before I sent this pull request.  Unfortunately a
  bad round of colds kept from addressing that in detail until today.
  The executive summary of the review was:

  Al: Is patching d_path really sufficient?
      The prepend_path, d_path, d_absolute_path, and __d_path family of
      functions is a really mess.

  Me: Yes, patching d_path is really sufficient.  Yes, the code is mess.
      No it is not appropriate to rewrite all of d_path for a regression
      that has existed for entirely too long already, when a two line
      change will do"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Fix a regression in mounting proc
  fork:  Allow CLONE_PARENT after setns(CLONE_NEWPID)
  vfs: In d_path don't call d_dname on a mount point

Pull KVM fix from Paolo Bonzini:
 "Fix for a brown paper bag bug.  Thanks to Drew Jones for noticing"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: fix apic_base enable check

Included change:
- properly compute the batman-adv header overhead. Such
  result is later used to initialize the hard_header_len
  member of the soft-interface netdev object
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull arm64 fix from Catalin Marinas:
 "Revert "arm64: Fix memory shareability attribute for ioremap_wc/cache"

  We noticed that it breaks ioremap (and earlyprintk) with 64K page
  configuration"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  Revert "arm64: Fix memory shareability attribute for ioremap_wc/cache"

Commit 74e72f89 ("lib/percpu_counter.c: fix __percpu_counter_add()")
looked very plausible, but its arithmetic was badly wrong: obvious once
you see the fix, but maddening to get there from the weird tmpfs ENOSPCs
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Fan Du <fan.du@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 7509963c (e1000e: Fix a compile flag mis-match for
suspend/resume) moved suspend and resume hooks to be available when
CONFIG_PM is set. However, it can be set even if CONFIG_PM_SLEEP is not set
causing following warnings to be emitted:

drivers/net/ethernet/intel/e1000e/netdev.c:6178:12: warning:
  	‘e1000_suspend’ defined but not used [-Wunused-function]

drivers/net/ethernet/intel/e1000e/netdev.c:6185:12: warning:
	‘e1000_resume’ defined but not used [-Wunused-function]

To fix this make the hooks to be available only when CONFIG_PM_SLEEP is set
and remove CONFIG_PM wrapping from driver ops because this is already
handled by SET_SYSTEM_SLEEP_PM_OPS() and SET_RUNTIME_PM_OPS().
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Dave Ertman <davidx.m.ertman@intel.com>
Cc: Aaron Brown <aaron.f.brown@intel.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 2f7dc602.

The above commit breaks the mapping type for Device memory because
pgprot_default already contains a Normal memory type. pgprot_default is
also not initialised early enough for earlyprintk resulting in an
inconsistent memory mapping with 64K PAGE_SIZE configuration.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>

On AMD family 10h we see following error messages while waking up from
S3 for all non-boot CPUs leading to a failed IBS initialization:

 Enabling non-boot CPUs ...
 smpboot: Booting Node 0 Processor 1 APIC 0x1
 [Firmware Bug]: cpu 1, try to use APIC500 (LVT offset 0) for vector 0x400, but the register is already in use for vector 0xf9 on another cpu
 perf: IBS APIC setup failed on cpu #1
 process: Switch to broadcast mode on CPU1
 CPU1 is up
 ...
 ACPI: Waking up from system sleep state S3

Reason for this is that during suspend the LVT offset for the IBS
vector gets lost and needs to be reinialized while resuming.

The offset is read from the IBSCTL msr. On family 10h the offset needs
to be 1 as offset 0 is used for the MCE threshold interrupt, but
firmware assings it for IBS to 0 too. The kernel needs to reprogram
the vector. The msr is a readonly node msr, but a new value can be
written via pci config space access. The reinitialization is
implemented for family 10h in setup_ibs_ctl() which is forced during
IBS setup.

This patch fixes IBS setup after waking up from S3 by adding
resume/supend hooks for the boot cpu which does the offset
reinitialization.

Marking it as stable to let distros pick up this fix.
Signed-off-by: NRobert Richter <rric@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> v3.2..
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1389797849-5565-1-git-send-email-rric.net@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Waiman managed to trigger a PMI while in a emulate_vsyscall() fault,
the PMI in turn managed to trigger a fault while obtaining a stack
trace. This triggered the sig_on_uaccess_error recursive fault logic
and killed the process dead.

Fix this by explicitly excluding interrupts from the recursive fault
logic.
Reported-and-Tested-by: NWaiman Long <waiman.long@hp.com>
Fixes: e00b12e6 ("perf/x86: Further optimize copy_from_user_nmi()")
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140110200603.GJ7572@laptop.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

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

Pull scheduler and timer fixes from Ingo Molnar:
 "Contains a fix for a scheduler bug that manifested itself as a 3D
  performance regression and a crash fix for the ARM Cadence TTC clock
  driver"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Calculate effective load even if local weight is 0

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: cadence_ttc: Fix mutex taken inside interrupt context

Pull locking fixes from Ingo Molnar:
 "Two fixes from lockdep coverage of seqlocks, which fix deadlocks on
  lockdep-enabled ARM systems"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched_clock: Disable seqlock lockdep usage in sched_clock()
  seqlock: Use raw_ prefix instead of _no_lockdep

Pull hwmon fix from Guenter Roeck:
 "Fix attribute length problem in coretemp driver"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (coretemp) Fix truncated name of alarm attributes

Pull ARM fixes from Russell King:
 "Another few fixes for ARM, nothing major here"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 7938/1: OMAP4/highbank: Flush L2 cache before disabling
  ARM: 7939/1: traps: fix opcode endianness when read from user memory
  ARM: 7937/1: perf_event: Silence sparse warning
  ARM: 7934/1: DT/kernel: fix arch_match_cpu_phys_id to avoid erroneous match
  Revert "ARM: 7908/1: mm: Fix the arm_dma_limit calculation"

Pull writeback fix from Wu Fengguang:
 "Fix data corruption on NFS writeback.

  It has been in linux-next for one month"

* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Fix data corruption on NFS

Pull i2c bugfix from Wolfram Sang.

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: Re-instate body of i2c_parent_is_i2c_adapter()

At first Jakub Zawadzki noticed that some divisions by reciprocal_divide
were not correct. (off by one in some cases)
http://www.wireshark.org/~darkjames/reciprocal-buggy.c

He could also show this with BPF:
http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c

The reciprocal divide in linux kernel is not generic enough,
lets remove its use in BPF, as it is not worth the pain with
current cpus.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NJakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Daniel Borkmann <dxchgb@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Matt Evans <matt@ozlabs.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>