linux-stable.git/include/linux, branch v3.14.2

bdi: avoid oops on device removal

2014-04-27T00:19:05+00:00

commit 5acda9d12dcf1ad0d9a5a2a7c646de3472fa7555 upstream.

After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue") when device is removed while we
are writing to it we crash in bdi_writeback_workfn() ->
set_worker_desc() because bdi->dev is NULL.

This can happen because even though bdi_unregister() cancels all pending
flushing work, nothing really prevents new ones from being queued from
balance_dirty_pages() or other places.

Fix the problem by clearing BDI_registered bit in bdi_unregister() and
checking it before scheduling of any flushing work.

Fixes: 839a8e8660b6777e7fe4e80af1a048aebe2b5977

Reviewed-by: Tejun Heo 
Signed-off-by: Jan Kara 
Cc: Derek Basehore 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

tty: Fix low_latency BUG

2014-04-27T00:19:04+00:00

commit a9c3f68f3cd8d55f809fbdb0c138ed061ea1bd25 upstream.

The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added several sleeping
locks (termios_rwsem and buf->lock) to the input processing path,
the frequency of these BUG reports has increased.

Note that changes in 3.12 did not introduce this regression;
sleeping locks were first added to the input processing path
with the removal of the BKL from N_TTY in commit
a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799bdf11625a831c5af33938dcb11908b6,
'tty: throttling race fix'. Since those changes, executing
flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe.

However, since most devices do not validate if the low_latency
setting is appropriate for the context (process or interrupt) in
which they receive data, some reports are due to misconfiguration.
Further, serial dma devices for which dma fails, resort to
interrupt receiving as a backup without resetting low_latency.

Historically, low_latency was used to force wake-up the reading
process rather than wait for the next scheduler tick. The
effect was to trim multiple milliseconds of latency from
when the process would receive new data.

Recent tests [1] have shown that the reading process now receives
data with only 10's of microseconds latency without low_latency set.

Remove the low_latency rx steering from tty_flip_buffer_push();
however, leave the knob as an optional hint to drivers that can
tune their rx fifos and such like. Cleanup stale code comments
regarding low_latency.

[1] https://lkml.org/lkml/2014/2/20/434

"Yay.. thats an annoying historical pain in the butt gone."
	-- Alan Cox

Reported-by: Beat Bolli 
Reported-by: Pavel Roskin 
Acked-by: David Sterba 
Cc: Grant Edwards 
Cc: Stanislaw Gruszka 
Cc: Hal Murray 
Signed-off-by: Peter Hurley 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test

2014-04-14T13:50:05+00:00

commit 03b8c7b623c80af264c4c8d6111e5c6289933666 upstream.

If an architecture has futex_atomic_cmpxchg_inatomic() implemented and there
is no runtime check necessary, allow to skip the test within futex_init().

This allows to get rid of some code which would always give the same result,
and also allows the compiler to optimize a couple of if statements away.

Signed-off-by: Heiko Carstens 
Cc: Finn Thain 
Cc: Geert Uytterhoeven 
Link: http://lkml.kernel.org/r/20140302120947.GA3641@osiris
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

ext4: atomically set inode->i_flags in ext4_set_inode_flags()

2014-03-31T00:02:06+00:00

Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Reported-by: John Sullivan 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

vlan: Warn the user if lowerdev has bad vlan features.

2014-03-28T21:16:51+00:00

Some drivers incorrectly assign vlan acceleration features to
vlan_features thus causing issues for Q-in-Q vlan configurations.
Warn the user of such cases.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

net: Account for all vlan headers in skb_mac_gso_segment

2014-03-28T21:10:36+00:00

skb_network_protocol() already accounts for multiple vlan
headers that may be present in the skb.  However, skb_mac_gso_segment()
doesn't know anything about it and assumes that skb->mac_len
is set correctly to skip all mac headers.  That may not
always be the case.  If we are simply forwarding the packet (via
bridge or macvtap), all vlan headers may not be accounted for.

A simple solution is to allow skb_network_protocol to return
the vlan depth it has calculated.  This way skb_mac_gso_segment
will correctly skip all mac headers.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors

2014-03-27T19:29:38+00:00

skb_zerocopy can copy elements of the frags array between skbs, but it doesn't
orphan them. Also, it doesn't handle errors, so this patch takes care of that
as well, and modify the callers accordingly. skb_tx_error() is also added to
the callers so they will signal the failed delivery towards the creator of the
skb.

Signed-off-by: Zoltan Kiss 
Signed-off-by: David S. Miller

usbnet: include wait queue head in device structure

2014-03-27T18:59:10+00:00

This fixes a race which happens by freeing an object on the stack.
Quoting Julius:
> The issue is
> that it calls usbnet_terminate_urbs() before that, which temporarily
> installs a waitqueue in dev->wait in order to be able to wait on the
> tasklet to run and finish up some queues. The waiting itself looks
> okay, but the access to 'dev->wait' is totally unprotected and can
> race arbitrarily. I think in this case usbnet_bh() managed to succeed
> it's dev->wait check just before usbnet_terminate_urbs() sets it back
> to NULL. The latter then finishes and the waitqueue_t structure on its
> stack gets overwritten by other functions halfway through the
> wake_up() call in usbnet_bh().

The fix is to just not allocate the data structure on the stack.
As dev->wait is abused as a flag it also takes a runtime PM change
to fix this bug.

Signed-off-by: Oliver Neukum 
Reported-by: Grant Grundler 
Tested-by: Grant Grundler 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-03-25T00:07:24+00:00

Pull networking fixes from David Miller:

 1) OpenVswitch's lookup_datapath() returns error pointers, so don't
    check against NULL.  From Jiri Pirko.

 2) pfkey_compile_policy() code path tries to do a GFP_KERNEL allocation
    under RCU locks, fix by using GFP_ATOMIC when necessary.  From
    Nikolay Aleksandrov.

 3) phy_suspend() indirectly passes uninitialized data into the ethtool
    get wake-on-land implementations.  Fix from Sebastian Hesselbarth.

 4) CPSW driver unregisters CPTS twice, fix from Benedikt Spranger.

 5) If SKB allocation of reply packet fails, vxlan's arp_reduce() defers
    a NULL pointer.  Fix from David Stevens.

 6) IPV6 neigh handling in vxlan doesn't validate the destination
    address properly, and it builds a packet with the src and dst
    reversed.  Fix also from David Stevens.

 7) Fix spinlock recursion during subscription failures in TIPC stack,
    from Erik Hugne.

 8) Revert buggy conversion of davinci_emac to devm_request_irq, from
    Chrstian Riesch.

 9) Wrong flags passed into forwarding database netlink notifications,
    from Nicolas Dichtel.

10) The netpoll neighbour soliciation handler checks wrong ethertype,
    needs to be ETH_P_IPV6 rather than ETH_P_ARP.  Fix from Li RongQing.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (34 commits)
  tipc: fix spinlock recursion bug for failed subscriptions
  vxlan: fix nonfunctional neigh_reduce()
  net: davinci_emac: Fix rollback of emac_dev_open()
  net: davinci_emac: Replace devm_request_irq with request_irq
  netpoll: fix the skb check in pkt_is_ns
  net: micrel : ks8851-ml: add vdd-supply support
  ip6mr: fix mfc notification flags
  ipmr: fix mfc notification flags
  rtnetlink: fix fdb notification flags
  tcp: syncookies: do not use getnstimeofday()
  netlink: fix setsockopt in mmap examples in documentation
  openvswitch: Correctly report flow used times for first 5 minutes after boot.
  via-rhine: Disable device in error path
  ATHEROS-ATL1E: Convert iounmap to pci_iounmap
  vxlan: fix potential NULL dereference in arp_reduce()
  cnic: Update version to 2.5.20 and copyright year.
  cnic,bnx2i,bnx2fc: Fix inconsistent use of page size
  cnic: Use proper ulp_ops for per device operations.
  net: cdc_ncm: fix control message ordering
  ipv6: ip6_append_data_mtu do not handle the mtu of the second fragment properly
  ...

Merge tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2014-03-21T05:09:30+00:00

Pull trace fix from Steven Rostedt:
 "Vaibhav Nagarnaik discovered that since 3.10 a clean-up patch made the
  array index in the trace event format bogus.

  He supplied an elegant solution that uses __stringify() and also
  removes the need for the event_storage and event_storage_mutex and
  also cuts off a few K of overhead from the trace events"

* tag 'trace-fixes-v3.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix array size mismatch in format string