neigh_table_init_no_netlink() is only used in net/core/neighbour.c file.
Signed-off-by: NHiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most machines dont use UDP encapsulation (L2TP)

Adds a static_key so that udp_queue_rcv_skb() doesnt have to perform a
test if L2TP never setup the encap_rcv on a socket.

Idea of this patch came after Simon Horman proposal to add a hook on TCP
as well.

If static_key is not yet enabled, the fast path does a single JMP .

When static_key is enabled, JMP destination is patched to reach the real
encap_type/encap_rcv logic, possibly adding cache misses.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: dev@openvswitch.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes possible null dereference in probe() function: when both
.mac_addr and .link_gpio are unknown, dev.platform_data may be NULL
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMike Sinkovsky <msink@permonline.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix spelling and references in rtnetlink.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change get_tx_queues, drop unsused arg/return value real_tx_queues,
and use return by value (with error) rather than call by reference.

Probably bonding should just change to LLTX and the whole get_tx_queues
API could disappear!
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In ancient times it was necessary to manually initialize the bus field of an
spi_driver to spi_bus_type. These days this is done in spi_driver_register() so
we can drop the manual assignment.

The patch was generated using the following coccinelle semantic patch:
// <smpl>
@@
identifier _driver;
@@
struct spi_driver _driver = {
	.driver = {
-		.bus = &spi_bus_type,
	},
};
// </smpl>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: Frederic Lambert <frdrc66@gmail.com>
Cc: netdev@vger.kernel.org
Acked-by: NGabor Juhos <juhosg@openwrt.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The comparison operators were backwards in both garp_attr_lookup and
garp_attr_create, so the entire GID rbtree was in reverse order.
(There was no practical side effect to this though, except that PDUs
were sent with attributes listed in reverse order, which is still
valid by the protocol. This change is only for clarity.)
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We discovered that PPPoATM has an excessively deep transmit queue. A
queue the size of the default socket send buffer (wmem_default) is
maintained between the PPP generic core and the ATM device.

Fix it to queue a maximum of *two* packets. The one the ATM device is
currently working on, and one more for the ATM driver to process
immediately in its TX done interrupt handler. The PPP core is designed
to feed packets to the channel with minimal latency, so that really
ought to be enough to keep the ATM device busy.

While we're at it, fix the fact that we were triggering the wakeup
tasklet on *every* pppoatm_pop() call. The comment saying "this is
inefficient, but doing it right is too hard" turns out to be overly
pessimistic... I think :)

On machines like the Traverse Geos, with a slow Geode CPU and two
high-speed ADSL2+ interfaces, there were reports of extremely high CPU
usage which could partly be attributed to the extra wakeups.

(The wakeup handling could actually be made a whole lot easier if we
 stop checking sk->sk_sndbuf altogether. Given that we now only queue
 *two* packets ever, one wonders what the point is. As it is, you could
 already deadlock the thing by setting the sk_sndbuf to a value lower
 than the MTU of the device, and it'd just block for ever.)
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do the initialization of the HSI interface when the
interface is opened, instead of upon registration.
When the interface is closed the HSI interface is
de-initialized, allowing other modules to use the
HSI interface.
Signed-off-by: NSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CAIF HSI is currently a virtual device. Stopping/starting the
queues is wrong on a virtual device.
Signed-off-by: NSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement aggregation algorithm, combining more data into a single
HSI transfer. 4 different traffic categories are supported:
 1. TC_PRIO_CONTROL .. TC_PRIO_MAX (CTL)
 2. TC_PRIO_INTERACTIVE            (VO)
 3. TC_PRIO_INTERACTIVE_BULK       (VI)
 4. TC_PRIO_BESTEFFORT, TC_PRIO_BULK, TC_PRIO_FILLER (BEBK)
Signed-off-by: NDmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Set traffic class for CAIF packets, based on socket
priority, CAIF protocol type, or type of message.

Traffic class mapping for different packet types:
 - control:       TC_PRIO_CONTROL;
 - flow control:  TC_PRIO_CONTROL;
 - at:            TC_PRIO_CONTROL;
 - rfm:           TC_PRIO_INTERACTIVE_BULK;
 - other sockets: equals to socket's TC;
 - network data:  no change.
Signed-off-by: NDmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull in the 'net' tree to get CAIF bug fixes upon which
the following set of CAIF feature patches depend.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use dev_dbg instead of dev_err for reporting in cfhsi_wakeup_cb.
Signed-off-by: NKim Lilliestierna <kim.xx.lilliestierna@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix memory leak of RX flip-buffer.
Signed-off-by: NSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added kfree_skb() calls in the chnk_net.c file on
the error paths.
Signed-off-by: NSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Applications using L2TP/IP sockets want to be able to bind() an L2TP/IP
socket to set the local tunnel id while leaving the auto-assigned source
address alone. So if no source address is supplied, don't overwrite
the address already stored in the socket.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The l2tp_ip socket close handler does not update the module refcount
correctly which prevents module unload after the first bind() call on
an L2TPv3 IP encapulation socket.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 2e57b79c misplaced its
parenthesis and now tx_fifo_errors will only be incremented if an
ENOMEM error is not written to the syslog.

Correct the parenthesis and indentation to the original goal of
counting all non ENOMEM errors and ratelimiting only the messages.
Signed-of-by: NTorsten Kaiser <just.for.lkml@googlemail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At the point of this error-handling code, alloc_skb has succeded, so free
the resulting skb by jumping to the err label.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recently an oops was reported in phonet if there was a failure during
network namespace creation.

[  163.733755] ------------[ cut here ]------------
[  163.734501] kernel BUG at include/net/netns/generic.h:45!
[  163.734501] invalid opcode: 0000 [#1] PREEMPT SMP
[  163.734501] CPU 2
[  163.734501] Pid: 19145, comm: trinity Tainted: G        W 3.4.0-rc1-next-20120405-sasha-dirty #57
[  163.734501] RIP: 0010:[<ffffffff824d6062>]  [<ffffffff824d6062>] phonet_pernet+0x182/0x1a0
[  163.734501] RSP: 0018:ffff8800674d5ca8  EFLAGS: 00010246
[  163.734501] RAX: 000000003fffffff RBX: 0000000000000000 RCX: ffff8800678c88d8
[  163.734501] RDX: 00000000003f4000 RSI: ffff8800678c8910 RDI: 0000000000000282
[  163.734501] RBP: ffff8800674d5cc8 R08: 0000000000000000 R09: 0000000000000000
[  163.734501] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880068bec920
[  163.734501] R13: ffffffff836b90c0 R14: 0000000000000000 R15: 0000000000000000
[  163.734501] FS:  00007f055e8de700(0000) GS:ffff88007d000000(0000) knlGS:0000000000000000
[  163.734501] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  163.734501] CR2: 00007f055e6bb518 CR3: 0000000070c16000 CR4: 00000000000406e0
[  163.734501] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  163.734501] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  163.734501] Process trinity (pid: 19145, threadinfo ffff8800674d4000, task ffff8800678c8000)
[  163.734501] Stack:
[  163.734501]  ffffffff824d5f00 ffffffff810e2ec1 ffff880067ae0000 00000000ffffffd4
[  163.734501]  ffff8800674d5cf8 ffffffff824d667a ffff880067ae0000 00000000ffffffd4
[  163.734501]  ffffffff836b90c0 0000000000000000 ffff8800674d5d18 ffffffff824d707d
[  163.734501] Call Trace:
[  163.734501]  [<ffffffff824d5f00>] ? phonet_pernet+0x20/0x1a0
[  163.734501]  [<ffffffff810e2ec1>] ? get_parent_ip+0x11/0x50
[  163.734501]  [<ffffffff824d667a>] phonet_device_destroy+0x1a/0x100
[  163.734501]  [<ffffffff824d707d>] phonet_device_notify+0x3d/0x50
[  163.734501]  [<ffffffff810dd96e>] notifier_call_chain+0xee/0x130
[  163.734501]  [<ffffffff810dd9d1>] raw_notifier_call_chain+0x11/0x20
[  163.734501]  [<ffffffff821cce12>] call_netdevice_notifiers+0x52/0x60
[  163.734501]  [<ffffffff821cd235>] rollback_registered_many+0x185/0x270
[  163.734501]  [<ffffffff821cd334>] unregister_netdevice_many+0x14/0x60
[  163.734501]  [<ffffffff823123e3>] ipip_exit_net+0x1b3/0x1d0
[  163.734501]  [<ffffffff82312230>] ? ipip_rcv+0x420/0x420
[  163.734501]  [<ffffffff821c8515>] ops_exit_list+0x35/0x70
[  163.734501]  [<ffffffff821c911b>] setup_net+0xab/0xe0
[  163.734501]  [<ffffffff821c9416>] copy_net_ns+0x76/0x100
[  163.734501]  [<ffffffff810dc92b>] create_new_namespaces+0xfb/0x190
[  163.734501]  [<ffffffff810dca21>] unshare_nsproxy_namespaces+0x61/0x80
[  163.734501]  [<ffffffff810afd1f>] sys_unshare+0xff/0x290
[  163.734501]  [<ffffffff8187622e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[  163.734501]  [<ffffffff82665539>] system_call_fastpath+0x16/0x1b
[  163.734501] Code: e0 c3 fe 66 0f 1f 44 00 00 48 c7 c2 40 60 4d 82 be 01 00 00 00 48 c7 c7 80 d1 23 83 e8 48 2a c4 fe e8 73 06 c8 fe 48 85 db 75 0e <0f> 0b 0f 1f 40 00 eb fe 66 0f 1f 44 00 00 48 83 c4 10 48 89 d8
[  163.734501] RIP  [<ffffffff824d6062>] phonet_pernet+0x182/0x1a0
[  163.734501]  RSP <ffff8800674d5ca8>
[  163.861289] ---[ end trace fb5615826c548066 ]---

After investigation it turns out there were two issues.
1) Phonet was not implementing network devices but was using register_pernet_device
   instead of register_pernet_subsys.

   This was allowing there to be cases when phonenet was not initialized and
   the phonet net_generic was not set for a network namespace when network
   device events were being reported on the netdevice_notifier for a network
   namespace leading to the oops above.

2) phonet_exit_net was implementing a confusing and special case of handling all
   network devices from going away that it was hard to see was correct, and would
   only occur when the phonet module was removed.

   Now that unregister_netdevice_notifier has been modified to synthesize unregistration
   events for the network devices that are extant when called this confusing special
   case in phonet_exit_net is no longer needed.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We already synthesize events in register_netdevice_notifier and synthesizing
events in unregister_netdevice_notifier allows to us remove the need for
special case cleanup code.

This change should be safe as it adds no new cases for existing callers
of unregiser_netdevice_notifier to handle.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added strict checking of PadN, as PadN can be used to increase header
size and thus push the protocol header into the 2nd fragment.

PadN is used to align the options within the Hop-by-Hop or
Destination Options header to 64-bit boundaries. The maximum valid
size is thus 7 bytes.
RFC 4942 recommends to actively check the "payload" itself and
ensure that it contains only zeroes.

See also RFC 4942 section 2.1.9.5.
Signed-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge fixes from Andrew Morton.

* emailed from Andrew Morton <akpm@linux-foundation.org>: (14 patches)
  panic: fix stack dump print on direct call to panic()
  drivers/rtc/rtc-pl031.c: enable clock on all ST variants
  Revert "mm: vmscan: fix misused nr_reclaimed in shrink_mem_cgroup_zone()"
  hugetlb: fix race condition in hugetlb_fault()
  drivers/rtc/rtc-twl.c: use static register while reading time
  drivers/rtc/rtc-s3c.c: add placeholder for driver private data
  drivers/rtc/rtc-s3c.c: fix compilation error
  MAINTAINERS: add PCDP console maintainer
  memcg: do not open code accesses to res_counter members
  drivers/rtc/rtc-efi.c: fix section mismatch warning
  drivers/rtc/rtc-r9701.c: reset registers if invalid values are detected
  drivers/char/random.c: fix boot id uniqueness race
  memcg: fix broken boolen expression
  memcg: fix up documentation on global LRU

Pull networking fixes from David Miller:

 1) Fix bluetooth userland regression reported by Keith Packard, from
    Gustavo Padovan.

 2) Revert ath9k PS idle change, from Sujith Manoharan.

 3) Correct default TCP memory limits (again), from Eric Dumazet.

 4) Fix tcp_rcv_rtt_update() accidental use of unscaled RTT, from Neal
    Cardwell.

 5) We made a facility for layers like wireless to say how much tailroom
    they need in the SKB for link layer stuff such as wireless
    encryption etc., but TCP works hard to fill every SKB out to the end
    defeating this specification.

    This leads to every TCP packet getting reallocated by the wireless
    code in order to have the right amount of tailroom available.

    Fix TCP to only fill SKBs out to the real amount of data area it
    asked for during the allocation, this way it won't eat into the
    slack added for the device's tailroom needs.

    Reported by Marc Merlin and fixed by Eric Dumazet.

 6) Leaks, endian bugs, and new device IDs in bluetooth from Santosh
    Nayak, João Paulo Rechi Vita, Cho, Yu-Chen, Andrei Emeltchenko,
    AceLan Kao, and Andrei Emeltchenko.

 7) OOPS on tty_close fix in bluetooth's hci_ldisc from Johan Hovold.

 8) netfilter erroneously scales TCP window twice, fix from Changli Gao.

 9) Memleak fix in wext-core from Julia Lawall.

10) Consistently handle invalid TCP packets in ipv4 vs.  ipv6 conntrack,
    from Jozsef Kadlecsik.

11) Validate IP header length properly in netfilter conntrack's
    ipv4_get_l4proto().

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (39 commits)
  NFC: Fix the LLCP Tx fragmentation loop
  rtlwifi: Add missing DMA buffer unmapping for PCI drivers
  rtlwifi: Preallocate USB read buffers and eliminate kalloc in read routine
  tcp: avoid order-1 allocations on wifi and tx path
  net: allow pskb_expand_head() to get maximum tailroom
  bridge: Do not send queries on multicast group leaves
  MAINTAINERS: Mark NATSEMI driver as orphan'd.
  tcp: fix tcp_rcv_rtt_update() use of an unscaled RTT sample
  tcp: restore correct limit
  Revert "ath9k: fix going to full-sleep on PS idle"
  rt2x00: Fix rfkill_polling register function.
  bcma: fix build error on MIPS; implicit pcibios_enable_device
  netfilter: nf_conntrack: fix incorrect logic in nf_conntrack_init_net
  netfilter: nf_ct_ipv4: packets with wrong ihl are invalid
  netfilter: nf_ct_ipv4: handle invalid IPv4 and IPv6 packets consistently
  net/wireless/wext-core.c: add missing kfree
  rtlwifi: Fix oops on rate-control failure
  mac80211: Convert WARN_ON to WARN_ON_ONCE
  rtlwifi: rtl8192de: Fix firmware initialization
  nl80211: ensure interface is up in various APIs
  ...

Pull drm fixes from Dave Airlie:
 "Mostly exynos and intel.

  Intel has 3 regression fixers (more info in intel merge commit), along
  with some other make hw work fixes, exynos has some cleanups and an
  ioctl fix.

  A couple of radeon fixes, couple of build fixes, and a savage
  userspace interface possible overflow fix."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (23 commits)
  drm/exynos: fixed exynos broken ioctl
  drm/i915: clear fencing tracking state when retiring requests
  drm/exynos: fix to pointer manager member of struct exynos_drm_subdrv
  drm/exynos: fix struct for operation callback functions to driver name
  drm/exynos: use define instead of default_win member in struct mixer_context
  drm/exynos: rename s/HDMI_OVERLAY_NUMBER/MIXER_WIN_NR
  drm/exynos: remove unused codes in hdmi and mixer
  drm/exynos: remove unnecessary type conversion of hdmi and mixer
  drm/i915: make rc6 module parameter read-only
  drm/i915: implement ColorBlt w/a
  drm/i915/ringbuffer: Exclude last 2 cachlines of ring on 845g
  Revert "drm/i915: reenable gmbus on gen3+ again"
  drm/radeon: only add the mm i2c bus if the hw_i2c module param is set
  vgaarb.h: fix build warnings
  drm/i915: properly compute dp dithering for user-created modes
  drm/radeon/kms: fix DVO setup on some r4xx chips
  drm/savage: fix integer overflows in savage_bci_cmdbuf()
  drm/radeon: replace udelay with mdelay for long timeouts
  drm/i915: Finish any pending operations on the framebuffer before disabling
  drm/i915: Removed IVB forced enable of sprite dest key.
  ...

Fixed coding style issues in net/core/utils.c
in relation with braces placement.
Signed-off-by: NJeffrin Jose <ahiliation@yahoo.co.in>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

extern int sysctl_mld_max_msf is already defined in linux/ipv6.h.
Signed-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull a few more fixes for md from NeilBrown:
 "Two are tagged for -stable.  They can cause an oops, but very rarely."

* tag 'md-3.4-fixes' of git://neil.brown.name/md:
  md/bitmap: prevent bitmap_daemon_work running while initialising bitmap
  md/raid1,raid10: Fix calculation of 'vcnt' when processing error recovery.
  MD: Bitmap version cleanup.

Commit 6e6f0a1f ("panic: don't print redundant backtraces on oops")
causes a regression where no stack trace will be printed at all for the
case where kernel code calls panic() directly while not processing an
oops, and of course there are 100's of instances of this type of call.

The original commit executed the check (!oops_in_progress), but this will
always be false because just before the dump_stack() there is a call to
bust_spinlocks(1), which does the following:

  void __attribute__((weak)) bust_spinlocks(int yes)
  {
	if (yes) {
		++oops_in_progress;

The proper way to resolve the problem that original commit tried to
solve is to avoid printing a stack dump from panic() when the either of
the following conditions is true:

  1) TAINT_DIE has been set (this is done by oops_end())
     This indicates and oops has already been printed.
  2) oops_in_progress > 1
     This guards against the rare case where panic() is invoked
     a second time, or in between oops_begin() and oops_end()
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>	[3.3+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ST variants of the PL031 all require bit 26 in the control register
to be set before they work properly.  Discovered this when testing on
the Nomadik board where it would suprisingly just stand still.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit c38446cc.

Before the commit, the code makes senses to me but not after the commit.
The "nr_reclaimed" is the number of pages reclaimed by scanning through
the memcg's lru lists.  The "nr_to_reclaim" is the target value for the
whole function.  For example, we like to early break the reclaim if
reclaimed 32 pages under direct reclaim (not DEF_PRIORITY).

After the reverted commit, the target "nr_to_reclaim" is decremented each
time by "nr_reclaimed" but we still use it to compare the "nr_reclaimed".
It just doesn't make sense to me...
Signed-off-by: NYing Han <yinghan@google.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The race is as follows:

Suppose a multi-threaded task forks a new process (on cpu A), thus
bumping up the ref count on all the pages.  While the fork is occurring
(and thus we have marked all the PTEs as read-only), another thread in
the original process (on cpu B) tries to write to a huge page, taking an
access violation from the write-protect and calling hugetlb_cow().  Now,
suppose the fork() fails.  It will undo the COW and decrement the ref
count on the pages, so the ref count on the huge page drops back to 1.
Meanwhile hugetlb_cow() also decrements the ref count by one on the
original page, since the original address space doesn't need it any
more, having copied a new page to replace the original page.  This
leaves the ref count at zero, and when we call unlock_page(), we panic.

	fork on CPU A				fault on CPU B
	=============				==============
	...
	down_write(&parent->mmap_sem);
	down_write_nested(&child->mmap_sem);
	...
	while duplicating vmas
		if error
			break;
	...
	up_write(&child->mmap_sem);
	up_write(&parent->mmap_sem);		...
						down_read(&parent->mmap_sem);
						...
						lock_page(page);
						handle COW
						page_mapcount(old_page) == 2
						alloc and prepare new_page
	...
	handle error
	page_remove_rmap(page);
	put_page(page);
	...
						fold new_page into pte
						page_remove_rmap(page);
						put_page(page);
						...
				oops ==>	unlock_page(page);
						up_read(&parent->mmap_sem);

The solution is to take an extra reference to the page while we are
holding the lock on it.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

RTC stores time and date in several registers.  Due to the fact that
these registers can't be read instantaneously, there is a chance that
reading from counting registers gives an error of one minute, one hour,
one day, etc.

To address this issue, the RTC has hardware support to copy the RTC
counting registers to static shadowed registers.  The current
implementation does not use this feature, and in a stress test, we can
reproduce this error at a rate of around two times per 300000 readings.

Fix the implementation to ensure that the right snapshot of time is
captured.
Signed-off-by: NKonstantin Shlyakhovoy <x0155534@ti.com>
Signed-off-by: NNishanth Menon <nm@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: linux-omap <linux-omap@vger.kernel.org>
Acked-by: NMykola Oleksiienko <x0174904@ti.com>
Acked-by: NOleksandr Dmytryshyn <oleksandr.dmytryshyn@ti.com>
Acked-by: NGraeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Driver data field is a pointer, hence assigning that to an integer results
in compilation warnings.

Fixes following compilation warnings:

  drivers/rtc/rtc-s3c.c: In function `s3c_rtc_get_driver_data':
  drivers/rtc/rtc-s3c.c:452:3: warning: return makes integer from pointer without a cast [enabled by default]
  drivers/rtc/rtc-s3c.c: At top level:
  drivers/rtc/rtc-s3c.c:674:3: warning: initialization makes pointer from integer without a cast [enabled by default]
  drivers/rtc/rtc-s3c.c:674:3: warning: (near initialization for `s3c_rtc_dt_match[1].data') [enabled by default]
  drivers/rtc/rtc-s3c.c:677:3: warning: initialization makes pointer from integer without a cast [enabled by default]
  drivers/rtc/rtc-s3c.c:677:3: warning: (near initialization for `s3c_rtc_dt_match[2].data') [enabled by default]
  drivers/rtc/rtc-s3c.c:680:3: warning: initialization makes pointer from integer without a cast [enabled by default]
  drivers/rtc/rtc-s3c.c:680:3: warning: (near initialization for `s3c_rtc_dt_match[3].data') [enabled by default]
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>