Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Veaceslav Falico <vfalico@redhat.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Paul Mackerras <paulus@samba.org>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Oliver Neukum <oliver@neukum.org>
CC: Steve Glendinning <steve.glendinning@shawell.net>
CC: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Santosh Raspatur <santosh@chelsio.com>
CC: Dimitris Michailidis <dm@chelsio.com>
CC: Michael Chan <mchan@broadcom.com>
CC: Santiago Leon <santil@linux.vnet.ibm.com>
CC: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
CC: Olof Johansson <olof@lixom.net>
CC: Manish Chopra <manish.chopra@qlogic.com>
CC: Sony Chacko <sony.chacko@qlogic.com>
CC: Rajesh Borundia <rajesh.borundia@qlogic.com>
CC: Nicolas Pitre <nico@fluxnic.net>
CC: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When running in a network namespace whose only link to the outside
world is a macvlan device, not being able to create a macvtap off of
it is a real pain.

So modify macvtap creation to automatically forward a creation of a
macvtap on a macvlan to become a creation of a macvtap on the
underlying network device, just like is currently done with
macvlan-on-macvlan devices.

v2: Use netif_is_macvlan and macvlan_dev_real_dev helpers to make it
    more clear what we're doing.
Signed-off-by: Kevin Wallace <kevin@pentabarf.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ben Hutchings says:

====================
SIOCGHWTSTAMP ioctl

1. Add the SIOCGHWTSTAMP ioctl and update the timestamping
documentation.
2. Implement SIOCGHWTSTAMP in most drivers that support SIOCSHWTSTAMP.
3. Add a test program to exercise SIOC{G,S}HWTSTAMP.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

John W. Linville says:

====================
Please pull this batch of fixes intende for the 3.13 stream!

For the mac80211 bits, Johannes says:

"For now I have various fixes all over, mostly for issues introduced in
relatively recent patches. There's no real pattern to it. Some of the
issues like go back longer, but still seemed 3.13 material."

And...

"These are just two patches disabling the broken CSA code. Once this
goes into your tree I'll merge it into mac80211-next and revert there
(since we fixed the bugs there)."

For the iwlwifi bits, Emmanuel says:

"I have here a few fixes for BT Coex. One of them is a NULL pointer
dereference. Another one avoids to enable a feature that can make the
firmware unhappy since the firmware isn't ready for it yet. WE also
avoid a WARNING that can be triggered upon association in not-so-bad
cases even if the association succeeded. We add support for new NICs
(not yet on the market) and bump the API so that 3.13 will be able to
work with the new firmware that will be out soon hopefully.
I also have a boundary check from Johannes."

In addition to those...

- Arend van Spriel fixes a brcmfmac problem that could use an
uninitialized variable in an error path.

- Borislav Petkov fixes a Kconfig-based build breakage problem for
brcmsmac.

- Michal Nazarewicz fixes a couple of NULL pointer dereference problems
in ath9k and wcn36xx.

- Sujith Manoharan fixes a couple of ath9k problems related to
incorrect interpretation of EEPROM configuration data.

- Ujjal Roy fixes a memory leak in mwifiex.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem

Hariprasad Shenai says:

====================
Fixes T5 adapter init, due to incorrect FW version check

This patch series fixes, Chelsio T5 adapter initialization failure due to
incorrect firmware version check. This patch series modifies the firmware
flashing mechanism for T4/T5 adapter.

The patch series moves chip type from struct adapter to struct adapter_params.
It changes the references of chip type in cxgb4 and cxgb4vf drivers such that
build failure is avoided.

Patch 3/3 is dependent on patch 1/3
Patch 2/3 is also dependent on patch 1/3

We would like to request this patch series to get merged via David Miller's
'net' tree.

We have included all the maintainers of respective drivers. Kindly review the
change and let us know in case of any review comments.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When driver registration fails, we need to clean up the resources allocated
before. mlx4_core missed destroying the workqueue allocated.

This patch destroys the workqueue when registration fails.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After congestion update on a local connection, when rds_ib_xmit returns
less bytes than that are there in the message, rds_send_xmit calls
back rds_ib_xmit with an offset that causes BUG_ON(off & RDS_FRAG_SIZE)
to trigger.

For a 4Kb PAGE_SIZE rds_ib_xmit returns min(8240,4096)=4096 when actually
the message contains 8240 bytes. rds_send_xmit thinks there is more to send
and calls rds_ib_xmit again with a data offset "off" of 4096-48(rds header)
=4048 bytes thus hitting the BUG_ON(off & RDS_FRAG_SIZE) [RDS_FRAG_SIZE=4k].

The commit 6094628b
"rds: prevent BUG_ON triggering on congestion map updates" introduced
this regression. That change was addressing the triggering of a different
BUG_ON in rds_send_xmit() on PowerPC architecture with 64Kbytes PAGE_SIZE:
 	BUG_ON(ret != 0 &&
    		 conn->c_xmit_sg == rm->data.op_nents);
This was the sequence it was going through:
(rds_ib_xmit)
/* Do not send cong updates to IB loopback */
if (conn->c_loopback
   && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
  	rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
    	return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
}
rds_ib_xmit returns 8240
rds_send_xmit:
  c_xmit_data_off = 0 + 8240 - 48 (rds header accounted only the first time)
   		 = 8192
  c_xmit_data_off < 65536 (sg->length), so calls rds_ib_xmit again
rds_ib_xmit returns 8240
rds_send_xmit:
  c_xmit_data_off = 8192 + 8240 = 16432, calls rds_ib_xmit again
  and so on (c_xmit_data_off 24672,32912,41152,49392,57632)
rds_ib_xmit returns 8240
On this iteration this sequence causes the BUG_ON in rds_send_xmit:
    while (ret) {
    	tmp = min_t(int, ret, sg->length - conn->c_xmit_data_off);
    	[tmp = 65536 - 57632 = 7904]
    	conn->c_xmit_data_off += tmp;
    	[c_xmit_data_off = 57632 + 7904 = 65536]
    	ret -= tmp;
    	[ret = 8240 - 7904 = 336]
    	if (conn->c_xmit_data_off == sg->length) {
    		conn->c_xmit_data_off = 0;
    		sg++;
    		conn->c_xmit_sg++;
    		BUG_ON(ret != 0 &&
    			conn->c_xmit_sg == rm->data.op_nents);
    		[c_xmit_sg = 1, rm->data.op_nents = 1]

What the current fix does:
Since the congestion update over loopback is not actually transmitted
as a message, all that rds_ib_xmit needs to do is let the caller think
the full message has been transmitted and not return partial bytes.
It will return 8240 (RDS_CONG_MAP_BYTES+48) when PAGE_SIZE is 4Kb.
And 64Kb+48 when page size is 64Kb.
Reported-by: Josh Hunt <joshhunt00@gmail.com>
Tested-by: Honggang Li <honli@redhat.com>
Acked-by: Bang Nguyen <bang.nguyen@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xenvif_start_xmit() relies on checking vif->task for NULL to determine
whether the vif is ready to accept packets. The task thread is stopped in
xenvif_disconnect() but task is not set to NULL. Thus, on a re-connect the
check will give a false positive.

Also since commit ea732dff (Handle backend
state transitions in a more robust way) it should not be possible for
xenvif_connect() to be called if the vif is already connected so change the
check of vif->tx_irq to a BUG_ON() and also add a BUG_ON(vif->task).
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 018c5bba.

It causes regressions for people using chips driven by the sungem
driver.  Suspicion is that the skb->csum value isn't being adjusted
properly.

The change also has a bug in that if __pskb_trim() fails, we'll leave
a corruped skb->csum value in there.  We would really need to revert
it to it's original value in that case.
Signed-off-by: David S. Miller <davem@davemloft.net>

Few network drivers really supports frag_list : virtual drivers.

Some drivers wrongly advertise NETIF_F_FRAGLIST feature.

If skb with a frag_list is given to them, packet on the wire will be
corrupt.

Remove this flag, as core networking stack will make sure to
provide packets that can be sent without corruption.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Cc: Anirudha Sarangi <anirudh@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The behaviour of blackhole and prohibit routes has been corrected by setting
the input and output pointers of the dst variable appropriately. For
blackhole routes, they are set to dst_discard and to ip6_pkt_discard and
ip6_pkt_discard_out respectively for prohibit routes.

ipv6: ip6_pkt_prohibit(_out) should not depend on
CONFIG_IPV6_MULTIPLE_TABLES

We need ip6_pkt_prohibit(_out) available without
CONFIG_IPV6_MULTIPLE_TABLES
Signed-off-by: Kamala R <kamala@aristanetworks.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On tx submit the driver always dma_map_single() FEC_ENET_TX_FRSIZE (=2048)
bytes. This works because we don't overwrite any memory after the data buffer,
we remove it from cache if it was there. So we hurt performace in case the
mapping of a smaller area makes a difference.
There is also a bug: If the data area starts shortly before the end of
RAM say 0xc7fffa10 and the RAM ends at 0xc8000000 then we have enough
space to fit the data area (according to skb->len) but we would map beyond
end of ram if we are using 2048. In v2.6.31 (against which kernel this patch
made) there is the following check in dma_cache_maint():

|BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(start + size - 1));

Since the area starting at 0xc8000000 is no longer virt_addr_valid() we
BUG() during dma_map_single(). The BUG() statement was removed in v3.5-rc1 as
per 2dc6a016 ("ARM: dma-mapping: use asm-generic/dma-mapping-common.h").

This patch was tested on v2.6.31 and then forward-ported and compile
tested only against the net tree. I think it is still worth fixing
mainline even after the BUG() statement is gone.
Tested-by: Fugang Duan <B38611@freescale.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When only one port of the two port is pinned out, then dt probe is failing
because second port phy is not found. fixing this by checking the number of
slaves and breaking the loop.
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Modify tg3_chip_reset() and tg3_close() to check if the PCI network
adapter device is accessible at all in order to skip poking it or
trying to handle a carrier loss in vain when that's not the case.
Introduce a special PCI helper function pci_device_is_present()
for this purpose.

Of course, this uncovers the lack of the appropriate RTNL locking
in tg3_suspend() and tg3_resume(), so add that locking in there
too.

These changes prevent tg3 from burning a CPU at 100% load level for
solid several seconds after the Thunderbolt link is disconnected from
a Matrox DS1 docking station.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

when dealing with a RA message, if accept_ra_defrtr is false,
the kernel will not add the default route, and then deal with
the following route information options. Unfortunately, those
options maybe contain default route, so let's judge the
accept_ra_defrtr before calling rt6_route_rcv.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull irq fixes from Thomas Gleixner:
 - Correction of fuzzy and fragile IRQ_RETVAL macro
 - IRQ related resume fix affecting only XEN
 - ARM/GIC fix for chained GIC controllers

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Gic: fix boot for chained gics
  irq: Enable all irqs unconditionally in irq_resume
  genirq: Correct fuzzy and fragile IRQ_RETVAL() definition

Pull scheduler fixes from Ingo Molnar:
 "Various smaller fixlets, all over the place"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Fix generation of device-drivers
  sched: Expose preempt_schedule_irq()
  sched: Fix a trivial typo in comments
  sched: Remove unused variable in 'struct sched_domain'
  sched: Avoid NULL dereference on sd_busy
  sched: Check sched_domain before computing group power
  MAINTAINERS: Update file patterns in the lockdep and scheduler entries

Pull perf fixes from Ingo Molnar:
 "Misc kernel and tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools lib traceevent: Fix conversion of pointer to integer of different size
  perf/trace: Properly use u64 to hold event_id
  perf: Remove fragile swevent hlist optimization
  ftrace, perf: Avoid infinite event generation loop
  tools lib traceevent: Fix use of multiple options in processing field
  perf header: Fix possible memory leaks in process_group_desc()
  perf header: Fix bogus group name
  perf tools: Tag thread comm as overriden

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 "Fixes to patches that went in this merge window along with a latent
  bug:
   - Fix lazy flushing in case m2p override fails.
   - Fix module compile issues with ARM/Xen
   - Add missing call to DMA map page for Xen SWIOTLB for ARM"

* tag 'stable/for-linus-3.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/gnttab: leave lazy MMU mode in the case of a m2p override failure
  xen/arm: p2m_init and p2m_lock should be static
  arm/xen: Export phys_to_mach to fix Xen module link errors
  swiotlb-xen: add missing xen_dma_map_page call

Building brcmfmac for sparc64 gave the following warning:

  CC [M]  drivers/net/wireless/brcm80211/brcmfmac/bcmsdh_sdmmc.o
    bcmsdh_sdmmc.c: In function 'brcmf_sdioh_request_byte':
     bcmsdh_sdmmc.c:89:6: warning: 'err_ret' may be used uninitialized
                          in this function [-Wuninitialized]

Inspecting the code it indeed had a path of execution in
which the return value was used uninitialized. This patch
fixes that code path.
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Franky Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

If kmalloc fails wcn36xx_smd_rsp_process will attempt to dereference
a NULL pointer.  There might be a better error recovery then just
printing an error, but printing an error message is better then the
current behaviour.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Code in ath9k_hw_set_clockrate function indicates that ah->curchan
(and thus chan local variable) may be NULL.  If that is indeed the
case, IS_CHAN_HT40(chan) check has to be performed only in branch
where chan is not NULL.  Moving the code under already existing
if condition fixes this issue.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

The EEPROM parameter to determine whether the bias
strength values for XLNA have to be applied is part
of the miscConfiguration field and not featureEnable.

Cc: stable@vger.kernel.org
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Bit 5 in the miscConfiguration field of the base EEPROM
header denotes whether QuickDrop is enabled or not. Fix
the incorrect usage of BIT(1) and also make sure that
this is done only for the required chips.

Cc: stable@vger.kernel.org
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Pull spi fixes from Mark Brown:
 "A smattering of driver specific fixes here, including a bunch for a
  long standing common pattern in the error handling paths, and a fix
  for an embarrassing thinko in the new devm master registration code"

* tag 'spi-v3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi/pxa2xx: Restore private register bits.
  spi/qspi: Fix qspi remove path.
  spi/qspi: cleanup pm_runtime error check.
  spi/qspi: set correct platform drvdata in ti_qspi_probe()
  spi/pxa2xx: add new ACPI IDs
  spi: core: invert success test in devm_spi_register_master
  spi: spi-mxs: fix reference leak to master in mxs_spi_remove()
  spi: bcm63xx: fix reference leak to master in bcm63xx_spi_remove()
  spi: txx9: fix reference leak to master in txx9spi_remove()
  spi: mpc512x: fix reference leak to master in mpc512x_psc_spi_do_remove()
  spi: rspi: use platform drvdata correctly in rspi_remove()
  spi: bcm2835: fix reference leak to master in bcm2835_spi_remove()

Pull networking updates from David Miller:
 "Here is a pile of bug fixes that accumulated while I was in Europe"

 1) In fixing kernel leaks to userspace during copying of socket
    addresses, we broke a case that used to work, namely the user
    providing a buffer larger than the in-kernel generic socket address
    structure.  This broke Ruby amongst other things.  Fix from Dan
    Carpenter.

 2) Fix regression added by byte queue limit support in 8139cp driver,
    from Yang Yingliang.

 3) The addition of MSG_SENDPAGE_NOTLAST buggered up a few sendpage
    implementations, they should just treat it the same as MSG_MORE.
    Fix from Richard Weinberger and Shawn Landden.

 4) Handle icmpv4 errors received on ipv6 SIT tunnels correctly, from
    Oussama Ghorbel.  In particular we should send an ICMPv6 unreachable
    in such situations.

 5) Fix some regressions in the recent genetlink fixes, in particular
    get the pmcraid driver to use the new safer interfaces correctly.
    From Johannes Berg.

 6) macvtap was converted to use a per-cpu set of statistics, but some
    code was still bumping tx_dropped elsewhere.  From Jason Wang.

 7) Fix build failure of xen-netback due to missing include on some
    architectures, from Andy Whitecroft.

 8) macvtap double counts received packets in statistics, fix from Vlad
    Yasevich.

 9) Fix various cases of using *_STATS_BH() when *_STATS() is more
    appropriate.  From Eric Dumazet and Hannes Frederic Sowa.

10) Pktgen ipsec mode doesn't update the ipv4 header length and checksum
    properly after encapsulation.  Fix from Fan Du.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (61 commits)
  net/mlx4_en: Remove selftest TX queues empty condition
  {pktgen, xfrm} Update IPv4 header total len and checksum after tranformation
  virtio_net: make all RX paths handle erors consistently
  virtio_net: fix error handling for mergeable buffers
  virtio_net: Fixed a trivial typo (fitler --> filter)
  netem: fix gemodel loss generator
  netem: fix loss 4 state model
  netem: missing break in ge loss generator
  net/hsr: Support iproute print_opt ('ip -details ...')
  net/hsr: Very small fix of comment style.
  MAINTAINERS: Added net/hsr/ maintainer
  ipv6: fix possible seqlock deadlock in ip6_finish_output2
  ixgbe: Make ixgbe_identify_qsfp_module_generic static
  ixgbe: turn NETIF_F_HW_L2FW_DOFFLOAD off by default
  ixgbe: ixgbe_fwd_ring_down needs to be static
  e1000: fix possible reset_task running after adapter down
  e1000: fix lockdep warning in e1000_reset_task
  e1000: prevent oops when adapter is being closed and reset simultaneously
  igb: Fixed Wake On LAN support
  inet: fix possible seqlock deadlocks
  ...

The pipe code was trying (and failing) to be very careful about freeing
the pipe info only after the last access, with a pattern like:

        spin_lock(&inode->i_lock);
        if (!--pipe->files) {
                inode->i_pipe = NULL;
                kill = 1;
        }
        spin_unlock(&inode->i_lock);
        __pipe_unlock(pipe);
        if (kill)
                free_pipe_info(pipe);

where the final freeing is done last.

HOWEVER.  The above is actually broken, because while the freeing is
done at the end, if we have two racing processes releasing the pipe
inode info, the one that *doesn't* free it will decrement the ->files
count, and unlock the inode i_lock, but then still use the
"pipe_inode_info" afterwards when it does the "__pipe_unlock(pipe)".

This is *very* hard to trigger in practice, since the race window is
very small, and adding debug options seems to just hide it by slowing
things down.

Simon originally reported this way back in July as an Oops in
kmem_cache_allocate due to a single bit corruption (due to the final
"spin_unlock(pipe->mutex.wait_lock)" incrementing a field in a different
allocation that had re-used the free'd pipe-info), it's taken this long
to figure out.

Since the 'pipe->files' accesses aren't even protected by the pipe lock
(we very much use the inode lock for that), the simple solution is to
just drop the pipe lock early.  And since there were two users of this
pattern, create a helper function for it.

Introduced commit ba5bb147 ("pipe: take allocation and freeing of
pipe_inode_info out of ->i_mutex").
Reported-by: Simon Kirby <sim@hostway.ca>
Reported-by: Ian Applegate <ia@cloudflare.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org   # v3.10+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When external CSA IEs are received (beacons or action messages), a
channel switch is triggered as well. This should only be allowed on
devices which actually support channel switches, otherwise disconnect.
(For the corresponding userspace invocation, the wiphy flag is checked
in nl80211).
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The channel switch announcement code has some major locking problems
which can cause a deadlock in worst case. A series of fixes has been
proposed, but these are non-trivial and need to be tested first.
Therefore disable CSA completely for 3.13.
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>