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 <zoltan.kiss@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, if the card supports CTAG acceleration we do not
account for the vlan header even if we are configuring an
8021AD vlan.  This may not be best since we'll do software
tagging for 8021AD which will cause data copy on skb head expansion
Configure the length based on available hw offload capabilities and
vlan protocol.

CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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 <oneukum@suse.de>
Reported-by: Grant Grundler <grundler@google.com>
Tested-by: Grant Grundler <grundler@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Current error handling of virtqueue_kick() was wrong in two places:
- The skb were freed immediately when virtqueue_kick() fail during
  xmit. This may lead double free since the skb was not detached from
  the virtqueue.
- try_fill_recv() returns false when virtqueue_kick() fail. This will
  lead unnecessary rescheduling of refill work.

Actually, it's safe to just ignore the kick failure in those two
places. So this patch fixes this by partially revert commit
67975901.

Fixes 67975901
(virtio_net: verify if virtqueue_kick() succeeded).

Cc: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some applications didn't expect recvmsg() on a non blocking socket
could return -EINTR. This possibility was added as a side effect
of commit b3ca9b02 ("net: fix multithreaded signal handling in
unix recv routines").

To hit this bug, you need to be a bit unlucky, as the u->readlock
mutex is usually held for very small periods.

Fixes: b3ca9b02 ("net: fix multithreaded signal handling in unix recv routines")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Thomas Petazzoni says:

====================
net: mvneta: fix usage as a module

The following set of two patches fix the usage of the mvneta driver
when built as a module, and used in RGMII configurations. It is
somewhat similar to a previous fix that was made by Arnaud Patard, but
which was limited to SGMII configurations.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The mvneta driver currently uses of_iomap(), which has two drawbacks:
it doesn't request the resource, and it isn't devm-style so some error
handling is needed.

This commit switches to use devm_ioremap_resource() instead, which
automatically requests the resource (so the I/O registers region shows
up properly in /proc/iomem), and also is devm-style, which allows to
get rid of some error handling to unmap the I/O registers region.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 5445eaf3 ('mvneta: Try to fix mvneta when compiled as
module') fixed the mvneta driver to make it work properly when loaded
as a module in SGMII configuration, which was tested successful by the
author on the Armada XP OpenBlocks AX3, which uses SGMII.

However, it turns out that the Armada XP GP, which uses RGMII, is
affected by a similar problem: its SERDES configuration is lost when
mvneta is loaded as a module, because this configuration is set by the
bootloader, and then lost because the clock is gated by the clock
framework until the mvneta driver is loaded again and the clock is
re-enabled.

However, it turns out that for the RGMII case, setting the SERDES
configuration is not sufficient: the PCS enable bit in the
MVNETA_GMAC_CTRL_2 register must also be set, like in the SGMII
configuration.

Therefore, this commit reworks the SGMII/RGMII initialization: the
only difference between the two now is a different SERDES
configuration, all the rest is identical.

In detail, to achieve this, the commit:

 * Renames MVNETA_SGMII_SERDES_CFG to MVNETA_SERDES_CFG because it is
   not specific to SGMII, but also used on RGMII configurations.

 * Adds a MVNETA_RGMII_SERDES_PROTO definition, that must be used as
   the MVNETA_SERDES_CFG value in RGMII configurations.

 * Removes the mvneta_gmac_rgmii_set() and mvneta_port_sgmii_config()
   functions, and instead directly do the SGMII/RGMII configuration in
   mvneta_port_up(), from where those functions where called. It is
   worth mentioning that mvneta_gmac_rgmii_set() had an 'enable'
   parameter that was always passed as '1', so it was pretty useless.

 * Reworks the mvneta_port_up() function to set the MVNETA_SERDES_CFG
   register to the appropriate value depending on the RGMII vs. SGMII
   configuration. It also unconditionally set the PCS_ENABLE bit (was
   already done for SGMII, but is now also needed for RGMII), and sets
   the PORT_RGMII bit (which was already done for both SGMII and
   RGMII).

This commit was successfully tested with mvneta compiled as a module,
on both the OpenBlocks AX3 (SGMII configuration) and the Armada XP GP
(RGMII configuration).
Reported-by: Steve McIntyre <steve@einval.com>
Cc: stable@vger.kernel.org # 3.11.x: 5445eaf3 mvneta: Try to fix mvneta when compiled as module
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bit 3 of the MVNETA_GMAC_CTRL_2 is actually used to enable the PCS,
not the PSC: there was a typo in the name of the define, which this
commit fixes.

Cc: stable@vger.kernel.org
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Including hardware acceleration features in vlan_features breaks
stacked vlans (Q-in-Q) by marking the bottom vlan interface as
capable of acceleration.  This causes one of the tags to be lost
and the packets are sent with a sing vlan header.

CC: Nithin Nayak Sujir <nsujir@broadcom.com>
CC: Michael Chan <mchan@broadcom.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 10ddceb2 (ip_tunnel:multicast process cause panic due
to skb->_skb_refdst NULL pointer) removed dst-drop call from
ip-tunnel-recv.

Following commit reintroduce dst-drop and fix the original bug by
checking loopback packet before releasing dst.
Original bug: https://bugzilla.kernel.org/show_bug.cgi?id=70681

CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull nfsd fix frm Bruce Fields:
 "J R Okajima sent this early and I was just slow to pass it along,
  apologies.  Fortunately it's a simple fix"

* 'nfsd-next' of git://linux-nfs.org/~bfields/linux:
  nfsd: fix lost nfserrno() call in nfsd_setattr()

Pull vfs fixes from Al Viro:
 "These four commits are obvious fixes (a couple of fdget_pos()-related
  ones from Eric Biggers, prepend_name() fix, missing checks for false
  negatives from __lookup_mnt() in fs/namei.c)"

For now I'm pulling just the four obvious fixes, there's another four
pending in Al's 'for-linus' branch wrt the mnt_hash list that were more
involved.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  rcuwalk: recheck mount_lock after mountpoint crossing attempts
  make prepend_name() work correctly when called with negative *buflen
  vfs: Don't let __fdget_pos() get FMODE_PATH files
  vfs: atomic f_pos access in llseek()

Pull parisc updates from Helge Deller:
 - revert parts of the latest patch regarding font selection with STICON
   console
 - wire up the utimes() syscall for parisc
 - remove the unused parisc tmpalias code and unnecessary arch*relax
   defines

* 'parisc-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: locks: remove redundant arch_*_relax operations
  parisc: wire up sys_utimes
  parisc: Remove unused CONFIG_PARISC_TMPALIAS code
  partly revert commit 8a10bc9d: parisc/sti_console: prefer Linux fonts over built-in ROM fonts

Pull sparc fixes from David Miller:

 1) Do serial locking in a way that makes things clear that these are
    IRQ spinlocks.

 2) Conversion to generic idle loop broke first generation Niagara
    machines, need to have %pil interrupts enabled during cpu yield
    hypervisor call.

 3) Do not use magic constants for iterations over tsb tables, from Doug
    Wilson.

 4) Fix erroneous truncation of 64-bit system call return values to
    32-bit.  From Dave Kleikamp.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Make sure %pil interrupts are enabled during hypervisor yield.
  sparc64:tsb.c:use array size macro rather than number
  sparc64: don't treat 64-bit syscall return codes as 32-bit
  sparc: serial: Clean up the locking for -rt

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
  ...

If a topology event subscription fails for any reason, such as out
of memory, max number reached or because we received an invalid
request the correct behavior is to terminate the subscribers
connection to the topology server. This is currently broken and
produces the following oops:

[27.953662] tipc: Subscription rejected, illegal request
[27.955329] BUG: spinlock recursion on CPU#1, kworker/u4:0/6
[27.957066]  lock: 0xffff88003c67f408, .magic: dead4ead, .owner: kworker/u4:0/6, .owner_cpu: 1
[27.958054] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.0-rc6+ #5
[27.960230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[27.960874] Workqueue: tipc_rcv tipc_recv_work [tipc]
[27.961430]  ffff88003c67f408 ffff88003de27c18 ffffffff815c0207 ffff88003de1c050
[27.962292]  ffff88003de27c38 ffffffff815beec5 ffff88003c67f408 ffffffff817f0a8a
[27.963152]  ffff88003de27c58 ffffffff815beeeb ffff88003c67f408 ffffffffa0013520
[27.964023] Call Trace:
[27.964292]  [<ffffffff815c0207>] dump_stack+0x45/0x56
[27.964874]  [<ffffffff815beec5>] spin_dump+0x8c/0x91
[27.965420]  [<ffffffff815beeeb>] spin_bug+0x21/0x26
[27.965995]  [<ffffffff81083df6>] do_raw_spin_lock+0x116/0x140
[27.966631]  [<ffffffff815c6215>] _raw_spin_lock_bh+0x15/0x20
[27.967256]  [<ffffffffa0008540>] subscr_conn_shutdown_event+0x20/0xa0 [tipc]
[27.968051]  [<ffffffffa000fde4>] tipc_close_conn+0xa4/0xb0 [tipc]
[27.968722]  [<ffffffffa00101ba>] tipc_conn_terminate+0x1a/0x30 [tipc]
[27.969436]  [<ffffffffa00089a2>] subscr_conn_msg_event+0x1f2/0x2f0 [tipc]
[27.970209]  [<ffffffffa0010000>] tipc_receive_from_sock+0x90/0xf0 [tipc]
[27.970972]  [<ffffffffa000fa79>] tipc_recv_work+0x29/0x50 [tipc]
[27.971633]  [<ffffffff8105dbf5>] process_one_work+0x165/0x3e0
[27.972267]  [<ffffffff8105e869>] worker_thread+0x119/0x3a0
[27.972896]  [<ffffffff8105e750>] ? manage_workers.isra.25+0x2a0/0x2a0
[27.973622]  [<ffffffff810648af>] kthread+0xdf/0x100
[27.974168]  [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0
[27.974893]  [<ffffffff815ce13c>] ret_from_fork+0x7c/0xb0
[27.975466]  [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0

The recursion occurs when subscr_terminate tries to grab the
subscriber lock, which is already taken by subscr_conn_msg_event.
We fix this by checking if the request to establish a new
subscription was successful, and if not we initiate termination of
the subscriber after we have released the subscriber lock.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The VXLAN neigh_reduce() code is completely non-functional since
check-in. Specific errors:

1) The original code drops all packets with a multicast destination address,
	even though neighbor solicitations are sent to the solicited-node
	address, a multicast address. The code after this check was never run.
2) The neighbor table lookup used the IPv6 header destination, which is the
	solicited node address, rather than the target address from the
	neighbor solicitation. So neighbor lookups would always fail if it
	got this far. Also for L3MISSes.
3) The code calls ndisc_send_na(), which does a send on the tunnel device.
	The context for neigh_reduce() is the transmit path, vxlan_xmit(),
	where the host or a bridge-attached neighbor is trying to transmit
	a neighbor solicitation. To respond to it, the tunnel endpoint needs
	to do a *receive* of the appropriate neighbor advertisement. Doing a
	send, would only try to send the advertisement, encapsulated, to the
	remote destinations in the fdb -- hosts that definitely did not do the
	corresponding solicitation.
4) The code uses the tunnel endpoint IPv6 forwarding flag to determine the
	isrouter flag in the advertisement. This has nothing to do with whether
	or not the target is a router, and generally won't be set since the
	tunnel endpoint is bridging, not routing, traffic.

	The patch below creates a proxy neighbor advertisement to respond to
neighbor solicitions as intended, providing proper IPv6 support for neighbor
reduction.
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Christian Riesch says:

====================
net: davinci_emac: Fix interrupt requests and error handling

since commit 6892b41d (Linux 3.11) the
davinci_emac driver is broken. After doing ifconfig down, ifconfig up,
requesting the interrupts for the driver fails. The interface remains dead
until the board is rebooted.

The first patch in this patchset reverts commit
6892b41d partially and makes the driver
useable again.

During the work on the first patch, a number of bugs in the error handling
of the driver's ndo_open code were found. The second patch fixes these bugs.

I believe the first patch meets the rules for stable kernels, I therefore added
the stable tag to this patch. The second patch is just cleanup, the code
that is fixed by this patch is only executed in case of an error.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

If an error occurs during the initialization in emac_dev_open() (the
driver's ndo_open function), interrupts, DMA descriptors etc. must be freed.
The current rollback code is buggy in several ways.

  1) Freeing the interrupts. The current code will not free all interrupts
     that were requested by the driver. Furthermore,  the code tries to do a
     platform_get_resource(priv->pdev, IORESOURCE_IRQ, -1) in its last
     iteration.

     This patch fixes these bugs.

  2) Wrong order of err: and rollback: labels. If the setup of the PHY in
     the code fails, the interrupts that have been requested before are
     not freed:

        request irq
                if requesting irqs fails, goto rollback
        setup phy
                if phy setup fails, goto err
        return 0

     rollback:
        free irqs
     err:

     This patch brings the code into the correct order.

  3) The code calls napi_enable() and emac_int_enable(), but does not
     undo both in case of an error.

     This patch adds calls of emac_int_disable() and napi_disable() to the
     rollback code.

  4) RX DMA descriptors are not freed in case of an error: Right before
     requesting the irqs, the function creates DMA descriptors for the
     RX channel. These RX descriptors are never freed when we jump to either
     rollback or err.

     This patch adds code for freeing the DMA descriptors in the case of
     an initialization error. This required a modification of
     cpdma_ctrl_stop() in davinci_cpdma.c: We must be able to call this
     function to free the DMA descriptors while the DMA channels are
     in IDLE state (before cpdma_ctlr_start() was called).

Tested on a custom board with the Texas Instruments AM1808.
Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

In commit 6892b41d

Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Date:   Tue Jun 25 21:24:51 2013 +0530
net: davinci: emac: Convert to devm_* api

the call of request_irq is replaced by devm_request_irq and the call
of free_irq is removed. But since interrupts are requested in
emac_dev_open, doing ifconfig up/down on the board requests the
interrupts again each time, causing devm_request_irq to fail. The
interface is dead until the device is rebooted.

This patch reverts said commit partially: It changes the driver back
to use request_irq instead of devm_request_irq, puts free_irq back in
place, but keeps the remaining changes of the original patch.
Reported-by: Jon Ringle <jon@ringle.org>
Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Neighbor Solicitation is ipv6 protocol, so we should check
skb->protocol with ETH_P_IPV6
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Cc: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In arch_cpu_idle() we must enable %pil based interrupts before
potentially invoking the hypervisor cpu yield call.

As per the Hypervisor API documentation for cpu_yield:

	Interrupts which are blocked by some mechanism other that
	pstate.ie (for example %pil) are not guaranteed to cause
	a return from this service.

It seems that only first generation Niagara chips are hit by this
bug.  My best guess is that later chips implement this in hardware
and wake up anyways from %pil events, whereas in first generation
chips the yield is implemented completely in hypervisor code and
requires %pil to be enabled in order to wake properly from this
call.

Fixes: 87fa05ae ("sparc: Use generic idle loop")
Reported-by: Fabio M. Di Nitto <fabbione@fabbione.net>
Reported-by: Jan Engelhardt <jengelh@inai.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Few platforms use external regulator to keep the ethernet MAC supplied.
So, request and enable the regulator for driver functionality.

Fixes: 66fda75f (regulator: core: Replace direct ops->disable usage)
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Suggested-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the arch_{spin,read,write}_relax macros default to cpu_relax(),
remove the redundant definitions for parisc.

Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Helge Deller <deller@gmx.de>

We seem to be nearly the only platform which does not provide the
sys_utimes syscall.  Adding it now makes our life much easier with
userspace applications (like dietlibc and e2fsprogs) since we then
behave like all other platforms too and don't need extra patches which
are hard to get upstream anyway because we are not a mainstream
architecture.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13

The attached change removes the unused and experimental
CONFIG_PARISC_TMPALIAS code. It doesn't work and I don't believe it will
ever be used.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

STI console is used on parisc and m68k HP machines. This patch partly reverts
my previous commit and as such restores the fonts for the m68k machines.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13

We can get false negative from __lookup_mnt() if an unrelated vfsmount
gets moved.  In that case legitimize_mnt() is guaranteed to fail,
and we will fall back to non-RCU walk... unless we end up running
into a hard error on a filesystem object we wouldn't have reached
if not for that false negative.  IOW, delaying that check until
the end of pathname resolution is wrong - we should recheck right
after we attempt to cross the mountpoint.  We don't need to recheck
unless we see d_mountpoint() being true - in that case even if
we have just raced with mount/umount, we can simply go on as if
we'd come at the moment when the sucker wasn't a mountpoint; if we
run into a hard error as the result, it was a legitimate outcome.
__lookup_mnt() returning NULL is different in that respect, since
it might've happened due to operation on completely unrelated
mountpoint.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

In all callchains leading to prepend_name(), the value left in *buflen
is eventually discarded unused if prepend_name() has returned a negative.
So we are free to do what prepend() does, and subtract from *buflen
*before* checking for underflow (which turns into checking the sign
of subtraction result, of course).

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Commit bd2a31d5 ("get rid of fget_light()") introduced the
__fdget_pos() function, which returns the resulting file pointer and
fdput flags combined in an 'unsigned long'.  However, it also changed the
behavior to return files with FMODE_PATH set, which shouldn't happen
because read(), write(), lseek(), etc. aren't allowed on such files.
This commit restores the old behavior.

This regression actually had no effect on read() and write() since
FMODE_READ and FMODE_WRITE are not set on file descriptors opened with
O_PATH, but it did cause lseek() on a file descriptor opened with O_PATH
to fail with ESPIPE rather than EBADF.
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Commit 9c225f26 ("vfs: atomic f_pos accesses as per POSIX") changed
several system calls to use fdget_pos() instead of fdget(), but missed
sys_llseek().  Fix it.
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull perf fixes from Ingo Molnar:
 "Two oneliner 'perf bench' tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf bench: Fix NULL pointer dereference in "perf bench all"
  perf bench numa: Make no args mean 'run all tests'

Pull ARM SoC fixes from Olof Johansson:
 "Only two patches this time, one to fix ethernet probe order on at91
  (better fix with proper device aliasing will be done for 3.15, this is
  stop-gap), and one update to MAINTAINERS due to Freescale moving their
  repo to kernel.org"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: at91: fix network interface ordering for sama5d36
  MAINTAINERS: update IMX kernel git tree

Pull drm fixes from Dave Airlie:
 "Some final few intel fixes, all regressions, all stable cc, and one
  exynos oops fixer.

  The biggest is probably the intel display error irqs one, but it seems
  to fix a few crashes on startup, and one use after free in drm core"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/exynos: Fix (more) freeing issues in exynos_drm_drv.c
  drm/i915: Disable stolen memory when DMAR is active
  Revert "drm/i915: don't touch the VDD when disabling the panel"
  drm: Fix use-after-free in the shadow-attache exit code
  drm/i915: Don't enable display error interrupts from the start
  drm/i915: Fix scanline counter fixup on BDW
  drm/i915: Add a workaround for HSW scanline counter weirdness
  drm/i915: Fix PSR programming

Commit 7982e90c ("block: fix q->flush_rq NULL pointer crash on
dm-mpath flush") moved an allocation to blk_init_allocated_queue(), but
neglected to free that allocation on the error paths that follow.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Srikar Dronamraju reports that commit b0c29f79 ("futexes: Avoid
taking the hb->lock if there's nothing to wake up") causes java threads
getting stuck on futexes when runing specjbb on a power7 numa box.

The cause appears to be that the powerpc spinlocks aren't using the same
ticket lock model that we use on x86 (and other) architectures, which in
turn result in the "spin_is_locked()" test in hb_waiters_pending()
occasionally reporting an unlocked spinlock even when there are pending
waiters.

So this reinstates Davidlohr Bueso's original explicit waiter counting
code, which I had convinced Davidlohr to drop in favor of figuring out
the pending waiters by just using the existing state of the spinlock and
the wait queue.
Reported-and-tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Original-code-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

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

Add remove_linear_migration_ptes_from_nonlinear(), to fix an interesting
little include/linux/swapops.h:131 BUG_ON(!PageLocked) found by trinity:
indicating that remove_migration_ptes() failed to find one of the
migration entries that was temporarily inserted.

The problem comes from remap_file_pages()'s switch from vma_interval_tree
(good for inserting the migration entry) to i_mmap_nonlinear list (no good
for locating it again); but can only be a problem if the remap_file_pages()
range does not cover the whole of the vma (zap_pte() clears the range).

remove_migration_ptes() needs a file_nonlinear method to go down the
i_mmap_nonlinear list, applying linear location to look for migration
entries in those vmas too, just in case there was this race.

The file_nonlinear method does need rmap_walk_control.arg to do this;
but it never needed vma passed in - vma comes from its own iteration.
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>