The rule for 'copy_from_user()' is that it zeroes the remaining kernel
buffer even when the copy fails halfway, just to make sure that we don't
leave uninitialized kernel memory around.  Because even if we check for
errors, some kernel buffers stay around after thge copy (think page
cache).

However, the x86-64 logic for user copies uses a copy_user_generic()
function for all the cases, that set the "zerorest" flag for any fault
on the source buffer.  Which meant that it didn't just try to clear the
kernel buffer after a failure in copy_from_user(), it also tried to
clear the destination user buffer for the "copy_in_user()" case.

Not only is that pointless, it also means that the clearing code has to
worry about the tail clearing taking page faults for the user buffer
case.  Which is just stupid, since that case shouldn't happen in the
first place.

Get rid of the whole "zerorest" thing entirely, and instead just check
if the destination is in kernel space or not.  And then just use
memset() to clear the tail of the kernel buffer if necessary.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull media updates from Mauro Carvalho Chehab:
 "A series of fixup patches for version 4.0:

   - one VB2 core fixup, when stopping the stream;
   - one VB2 core fixup for dma-contig memory type;
   - driver fixes at rtl28xx, s5p (tv, jpeg, mfc, soc-camera, sh_veu,
     cx23885, gspca"

* tag 'media/v3.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] rtl28xxu: return success for unimplemented FE callback
  [media] rtl2832: disable regmap register cache
  [media] vb2: Fix dma_dir setting for dma-contig mem type
  [media] media: s5p-mfc: fix broken pointer cast on 64bit arch
  [media] media: s5p-mfc: fix mmap support for 64bit arch
  [media] cx23885: fix querycap
  [media] sh_veu: v4l2_dev wasn't set
  [media] s5p-mfc: Fix NULL pointer dereference caused by not set q->lock
  [media] s5p-jpeg: exynos3250: fix erroneous reset procedure
  [media] s5p-tv: hdmi needs I2C support
  [media] s5p-jpeg: Initialize cb and cr to zero
  [media] media: fix gspca drivers build dependencies
  [media] soc-camera: Fix devm_kfree() in soc_of_bind()
  [media] media: atmel-isi: increase the burst length to improve the performance
  [media] vb2: fix 'UNBALANCED' warnings when calling vb2_thread_stop()

Pull networking fixes from David Miller:

 1) In TCP, don't register an FRTO for cumulatively ACK'd data that was
    previously SACK'd, from Neal Cardwell.

 2) Need to hold RNL mutex in ipv4 multicast code namespace cleanup,
    from Cong WANG.

 3) Similarly we have to hold RNL mutex for fib_rules_unregister(), also
    from Cong WANG.

 4) Revert and rework netns nsid allocation fix, from Nicolas Dichtel.

 5) When we encapsulate for a tunnel device, skb->sk still points to the
    user socket.  So this leads to cases where we retraverse the
    ipv4/ipv6 output path with skb->sk being of some other address
    family (f.e. AF_PACKET).  This can cause things to crash since the
    ipv4 output path is dereferencing an AF_PACKET socket as if it were
    an ipv4 one.

    The short term fix for 'net' and -stable is to elide these socket
    checks once we've entered an encapsulation sequence by testing
    xmit_recursion.

    Longer term we have a better solution wherein we pass the tunnel's
    socket down through the output paths, but that is way too invasive
    for 'net' and -stable.

    From Hannes Frederic Sowa.

 6) l2tp_init() failure path forgets to unregister per-net ops, from
    Cong WANG.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net/mlx4_core: Fix error message deprecation for ConnectX-2 cards
  net: dsa: fix filling routing table from OF description
  l2tp: unregister l2tp_net_ops on failure path
  mvneta: dont call mvneta_adjust_link() manually
  ipv6: protect skb->sk accesses from recursive dereference inside the stack
  netns: don't allocate an id for dead netns
  Revert "netns: don't clear nsid too early on removal"
  ip6mr: call del_timer_sync() in ip6mr_free_table()
  net: move fib_rules_unregister() under rtnl lock
  ipv4: take rtnl_lock and mark mrt table as freed on namespace cleanup
  tcp: fix FRTO undo on cumulative ACK of SACKed range
  xen-netfront: transmit fully GSO-sized packets

Commit 1daa4303 ("net/mlx4_core: Deprecate error message at
ConnectX-2 cards startup to debug") did the deprecation only for port 1
of the card. Need to deprecate for port 2 as well.

Fixes: 1daa4303

 ("net/mlx4_core: Deprecate error message at ConnectX-2 cards startup to debug")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to description in 'include/net/dsa.h', in cascade switches
configurations where there are more than one interconnected devices,
'rtable' array in 'dsa_chip_data' structure is used to indicate which
port on this switch should be used to send packets to that are destined
for corresponding switch.

However, dsa_of_setup_routing_table() fills 'rtable' with port numbers
of the _target_ switch, but not current one.

This commit removes redundant devicetree parsing and adds needed port
number as a function argument. So dsa_of_setup_routing_table() now just
looks for target switch number by parsing parent of 'link' device node.

To remove possible misunderstandings with the way of determining target
switch number, a corresponding comment was added to the source code and
to the DSA device tree bindings documentation file.

This was tested on a custom board with two Marvell 88E6095 switches with
following corresponding routing tables: { -1, 10 } and { 8, -1 }.

Signed-off-by: Pavel Nakonechny <pavel.nakonechny@skitlab.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull input fixes from Dmitry Torokhov:
 "Updates for the input subsystem - two more tweaks for ALPS driver to
  work out kinks after splitting the touchpad, trackstick, and potential
  external PS/2 mouse into separate input devices.

  Changes to support ALPS SS4 devices (protocol V8) will be coming in
  4.1..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: alps - document stick behavior for protocol V2
  Input: alps - report V2 Dualpoint Stick events via the right evdev node
  Input: alps - report interleaved bare PS/2 packets via dev3

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mvneta_adjust_link() is a callback for of_phy_connect() and should
not be called directly. The result of calling it directly is as below:

Signed-off-by: David S. Miller <davem@davemloft.net>

We should not consult skb->sk for output decisions in xmit recursion
levels > 0 in the stack. Otherwise local socket settings could influence
the result of e.g. tunnel encapsulation process.

ipv6 does not conform with this in three places:

1) ip6_fragment: we do consult ipv6_npinfo for frag_size

2) sk_mc_loop in ipv6 uses skb->sk and checks if we should
   loop the packet back to the local socket

3) ip6_skb_dst_mtu could query the settings from the user socket and
   force a wrong MTU

Furthermore:
In sk_mc_loop we could potentially land in WARN_ON(1) if we use a
PF_PACKET socket ontop of an IPv6-backed vxlan device.

Reuse xmit_recursion as we are currently only interested in protecting
tunnel devices.

Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Document that protocol V2 uses standard (bare) PS/2 mouse packets for the
DualPoint stick.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-By: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

On V2 devices the DualPoint Stick reports bare packets, these should be
reported via the "AlpsPS/2 ALPS DualPoint Stick" dev2 evdev node, which also
has the INPUT_PROP_POINTING_STICK propbit set.

Note that since there is no way to distinguish these packets from an external
PS/2 mouse (insofar as these laptops have an external PS/2 port) this means
that we will be reporting PS/2 mouse events via this evdev node too, as we've
been doing in kernel 3.19 and older.

This has been tested on a Dell Latitude D620 and a Dell Latitude E6400,
which both have a V2 touchpad + a DualPoint Stick which reports bare packets.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Bare packets should be reported via the same evdev device independent on
whether they are detected on the beginning of a packet or in the middle
of a packet.

This has been tested on a Dell Latitude E6400, where the DualPoint Stick
reports bare packets, which get reported via dev3 when the touchpad is
idle, and via dev2 when the touchpad and stick are used simultaneously.

This commit fixes this inconsistency by always reporting bare packets via
dev3. Note that since the come from a DualPoint Stick they really should be
reported via dev2, this gets fixed in a later commit.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Pull USB fixes from Greg KH:
 "Here are some small USB fixes and new device ids for 4.0-rc6.  Nothing
  major, some xhci fixes for reported problems, and some usb-serial
  device ids.

  All have been in linux-next for a while"

* tag 'usb-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: ftdi_sio: Use jtag quirk for SNAP Connect E10
  usb: isp1760: fix spin unlock in the error path of isp1760_udc_start
  usb: xhci: apply XHCI_AVOID_BEI quirk to all Intel xHCI controllers
  usb: xhci: handle Config Error Change (CEC) in xhci driver
  USB: keyspan_pda: add new device id
  USB: ftdi_sio: Added custom PID for Synapse Wireless product

Pull staging driver fixes from Greg KH:
 "Here are some staging driver fixes, well, really all just IIO driver
  fixes, for 4.0-rc6.  They fix issues that have been reported with
  these drivers.

  All of these patches have been in linux-next for a while"

* tag 'staging-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: imu: Use iio_trigger_get for indio_dev->trig assignment
  iio: adc: vf610: use ADC clock within specification
  iio/adc/cc10001_adc.c: Fix !HAS_IOMEM build
  iio: core: Fix double free.
  iio:inv-mpu6050: Fix inconsistency for the scale channel
  staging: iio: dummy: Fix undefined symbol build error
  iio: inv_mpu6050: Clear timestamps fifo while resetting hardware fifo
  staging: iio: hmc5843: Set iio name property in sysfs
  iio: bmc150: change sampling frequency
  iio: fix drivers that check buffer->scan_mask

Pull tty/serial fixes from Greg KH:
 "Here are 3 serial driver fixes for 4.0-rc6.  They fix some reported
  issues with the samsung and fsl_lpuart drivers.

  All have been in linux-next for a while"

* tag 'tty-4.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: serial: fsl_lpuart: clear receive flag on FIFO flush
  tty: serial: fsl_lpuart: specify transmit FIFO size
  serial: samsung: Clear operation mode on UART shutdown

Pull input subsystem fixes from Dmitry Torokhov:
 "A fix for ALPS driver for issue introduced in the latest update and a
  tweak for yet another Lenovo box in Synaptics.

  There will be more ALPS tweaks coming.."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: define INPUT_PROP_ACCELEROMETER behavior
  Input: synaptics - fix min-max quirk value for E440
  Input: synaptics - add quirk for Thinkpad E440
  Input: ALPS - fix max coordinates for v5 and v7 protocols
  Input: add MT_TOOL_PALM

Pull block layer fix from Jens Axboe:
 "Just one patch in this pull request, fixing a regression caused by a
  'mathematically correct' change to lcm()"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix blk_stack_limits() regression due to lcm() change

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: a SYSRET single-stepping fix, a dmi-scan robustization
  fix, a reboot quirk and a kgdb fixlet"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kgdb/x86: Fix reporting of 'si' in kgdb on x86_64
  x86/asm/entry/64: Disable opportunistic SYSRET if regs->flags has TF set
  x86/reboot: Add ASRock Q1900DC-ITX mainboard reboot quirk
  MAINTAINERS: Change the x86 microcode loader maintainer
  firmware: dmi_scan: Prevent dmi_num integer overflow

Pull perf fixes from Ingo Molnar:
 "Two x86 Intel PMU constraint handling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix Haswell CYCLE_ACTIVITY.* counter constraints
  perf/x86/intel: Filter branches for PEBS event

Pull devicetree fix from Grant Likely:
 "Simple bugfix for bad device tree data on the PA-Semi platform"

* tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux:
  drivers/of: Add empty ranges quirk for PA-Semi

Pull CIFS fixes from Steve French:
 "A set of small cifs fixes fixing a memory leak, kernel oops, and
  infinite loop (and some spotted by Coverity)"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  Fix warning
  Fix another dereference before null check warning
  CIFS: session servername can't be null
  Fix warning on impossible comparison
  Fix coverity warning
  Fix dereference before null check warning
  Don't ignore errors on encrypting password in SMBTcon
  Fix warning on uninitialized buftype
  cifs: potential memory leaks when parsing mnt opts
  cifs: fix use-after-free bug in find_writable_file
  cifs: smb2_clone_range() - exit on unhandled error

First, let's explain the problem.
Suppose you have an ipip interface that stands in the netns foo and its link
part in the netns bar (so the netns bar has an nsid into the netns foo).
Now, you remove the netns bar:
 - the bar nsid into the netns foo is removed
 - the netns exit method of ipip is called, thus our ipip iface is removed:
   => a netlink message is built in the netns foo to advertise this deletion
   => this netlink message requests an nsid for bar, thus a new nsid is
      allocated for bar and never removed.

This patch adds a check in peernet2id() so that an id cannot be allocated for
a netns which is currently destroyed.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts
commit 4217291e

 ("netns: don't clear nsid too early on removal").

This is not the right fix, it introduces races.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We need to wait for the flying timers, since we
are going to free the mrtable right after it.

Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We have to hold rtnl lock for fib_rules_unregister()
otherwise the following race could happen:

fib_rules_unregister():	fib_nl_delrule():
...				...
...				ops = lookup_rules_ops();
list_del_rcu(&ops->list);
				list_for_each_entry(ops->rules) {
fib_rules_cleanup_ops(ops);	  ...
  list_del_rcu();		  list_del_rcu();
				}

Note, net->rules_mod_lock is actually not needed at all,
either upper layer netns code or rtnl lock guarantees
we are safe.

Cc: Alexander Duyck <alexander.h.duyck@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is the IPv4 part for commit 905a6f96


(ipv6: take rtnl_lock and mark mrt6 table as freed on namespace cleanup).

Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull drm fixes from Dave Airlie:
 "One drm core fix, one exynos regression fix, two sets of radeon fixes
  (Alex was a bit behind last week), and two i915 fixes.

  Nothing too serious we seem to have calmed down i915 since last week"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon: fix wait in radeon_mn_invalidate_range_start
  drm/radeon: add extra check in radeon_ttm_tt_unpin_userptr
  drm: Exynos: Respect framebuffer pitch for FIMD/Mixer
  drm/i915: Reject the colorkey ioctls for primary and cursor planes
  drm/i915: Skip allocating shadow batch for 0-length batches
  drm/radeon: programm the VCE fw BAR as well
  drm/radeon: always dump the ring content if it's available
  radeon: Do not directly dereference pointers to BIOS area.
  drm/radeon/dpm: fix 120hz handling harder
  drm/edid: set ELD for firmware and debugfs override EDIDs

Pull irqchip fixes from Jason Cooper:
 "This is the second round of fixes for irqchip.  It contains some fixes
  found while the arm64 guys were writing the kvm gicv3 its emulation.

  GICv3 ITS:
    - Small batch of fixes discovered while writing the kvm ITS emulation"

* tag 'irqchip-fixes-4.0-2' of git://git.infradead.org/users/jcooper/linux:
  irqchip: gicv3-its: Use non-cacheable accesses when no shareability
  irqchip: gicv3-its: Fix PROP/PEND and BASE/CBASE confusion
  irqchip: gicv3-its: Fix device ID encoding
  irqchip: gicv3-its: Fix encoding of collection's target redistributor

Just two small fixes for radeon, both destined for stable.

* 'drm-fixes-4.0' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: fix wait in radeon_mn_invalidate_range_start
  drm/radeon: add extra check in radeon_ttm_tt_unpin_userptr

Merge branch 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes

Fix display on issue to Exynos5250 based Snow(1366x768) board.

* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm: Exynos: Respect framebuffer pitch for FIMD/Mixer

one oops fixes and a 0-length allocation fix from next backported.

* tag 'drm-intel-fixes-2015-04-02' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Reject the colorkey ioctls for primary and cursor planes
  drm/i915: Skip allocating shadow batch for 0-length batches

Here's a single drm core fix, cc: stable, that affects i915
users.

* tag 'topic/drm-fixes-2015-04-02' of git://anongit.freedesktop.org/drm-intel:
  drm/edid: set ELD for firmware and debugfs override EDIDs

Return success for FE callback on case we don't have any special
implementation. fc0013 tuner driver calls that callback in order to
switch antenna input, even we don't provide antenna switch.
Returning error caused fc0013 driver given up tuning.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Caching register reads causes some random I/O errors on channel
change. Disable caching now in order to avoid those errors.

Reverts partly commit dcadb82a



Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Pull xen regression fixes from David Vrabel:
 "Fix two regressions in the balloon driver's use of memory hotplug when
  used in a PV guest"

* tag 'stable/for-linus-4.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: before adding hotplugged memory, set frames to invalid
  x86/xen: prepare p2m list for memory hotplug

Pull powerpc fix from Michael Ellerman:
 "Fix memory corruption by pnv_alloc_idle_core_states"

* tag 'powerpc-4.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc: fix memory corruption by pnv_alloc_idle_core_states

On processing cumulative ACKs, the FRTO code was not checking the
SACKed bit, meaning that there could be a spurious FRTO undo on a
cumulative ACK of a previously SACKed skb.

The FRTO code should only consider a cumulative ACK to indicate that
an original/unretransmitted skb is newly ACKed if the skb was not yet
SACKed.

The effect of the spurious FRTO undo would typically be to make the
connection think that all previously-sent packets were in flight when
they really weren't, leading to a stall and an RTO.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Fixes: e33099f9

 ("tcp: implement RFC5682 F-RTO")
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull infiniband/rdma fix from Roland Dreier:
 "Fix for exploitable integer overflow in uverbs interface"

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic

xen-netfront limits transmitted skbs to be at most 44 segments in size. However,
GSO permits up to 65536 bytes, which means a maximum of 45 segments of 1448
bytes each. This slight reduction in the size of packets means a slight loss in
efficiency.

Since c/s 9ecd1a75, xen-netfront sets gso_max_size to
    XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER,
where XEN_NETIF_MAX_TX_SIZE is 65535 bytes.

The calculation used by tcp_tso_autosize (and also tcp_xmit_size_goal since c/s
6c09fa09) in determining when to split an skb into two is
    sk->sk_gso_max_size - 1 - MAX_TCP_HEADER.

So the maximum permitted size of an skb is calculated to be
    (XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER) - 1 - MAX_TCP_HEADER.

Intuitively, this looks like the wrong formula -- we don't need two TCP headers.
Instead, there is no need to deviate from the default gso_max_size of 65536 as
this already accommodates the size of the header.

Currently, the largest skb transmitted by netfront is 63712 bytes (44 segments
of 1448 bytes each), as observed via tcpdump. This patch makes netfront send
skbs of up to 65160 bytes (45 segments of 1448 bytes each).

Similarly, the maximum allowable mtu does not need to subtract MAX_TCP_HEADER as
it relates to the size of the whole packet, including the header.

Fixes: 9ecd1a75

 ("xen-netfront: reduce gso_max_size to account for max TCP header")
Signed-off-by: Jonathan Davies <jonathan.davies@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>