* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (24 commits)
  bridge: Partially disable netpoll support
  tcp: fix crash in tcp_xmit_retransmit_queue
  IPv6: fix CoA check in RH2 input handler (mip6_rthdr_input())
  ibmveth: lost IRQ while closing/opening device leads to service loss
  rt2x00: Fix lockdep warning in rt2x00lib_probe_dev()
  vhost: avoid pr_err on condition guest can trigger
  ipmr: Don't leak memory if fib lookup fails.
  vhost-net: avoid flush under lock
  net: fix problem in reading sock TX queue
  net/core: neighbour update Oops
  net: skb_tx_hash() fix relative to skb_orphan_try()
  rfs: call sock_rps_record_flow() in tcp_splice_read()
  xfrm: do not assume that template resolving always returns xfrms
  hostap_pci: set dev->base_addr during probe
  axnet_cs: use spin_lock_irqsave in ax_interrupt
  dsa: Fix Kconfig dependencies.
  act_nat: not all of the ICMP packets need an IP header payload
  r8169: incorrect identifier for a 8168dp
  Phonet: fix skb leak in pipe endpoint accept()
  Bluetooth: Update sec_level/auth_type for already existing connections
  ...

If a single-threaded process does a file-descriptor operation, and some
other process accesses that same file descriptor via /proc, the current
rcu_dereference_check_fdtable() can give a false-positive RCU-lockdep
splat due to the reference count being increased by the /proc access after
the reference-count check in fget_light() but before the check in
rcu_dereference_check_fdtable().

This commit prevents this false positive by checking for a single-threaded
process.  To avoid #include hell, this commit uses the wrapper for
thread_group_empty(current) defined by rcu_my_thread_group_empty()
provided in a separate commit.
Located-by: NMiles Lane <miles.lane@gmail.com>
Located-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

System will crash sooner or later once the memory with the code of the
s3c-sdhci.ko module is reused for something else. I really have no idea
how the lack of remove function went unnoticed into the mainline code.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

My Collabora address is no longer enabled - update the MODULE_AUTHOR
fields of drivers to my current email address.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Borislav Petkov reported his 32bit numa system has problem:

[    0.000000] Reserving total of 4c00 pages for numa KVA remap
[    0.000000] kva_start_pfn ~ 32800 max_low_pfn ~ 375fe
[    0.000000] max_pfn = 238000
[    0.000000] 8202MB HIGHMEM available.
[    0.000000] 885MB LOWMEM available.
[    0.000000]   mapped low ram: 0 - 375fe000
[    0.000000]   low ram: 0 - 375fe000
[    0.000000] alloc (nid=8 100000 - 7ee00000) (1000000 - ffffffff) 1000 1000 => 34e7000
[    0.000000] alloc (nid=8 100000 - 7ee00000) (1000000 - ffffffff) 200 40 => 34c9d80
[    0.000000] alloc (nid=0 100000 - 7ee00000) (1000000 - ffffffffffffffff) 180 40 => 34e6140
[    0.000000] alloc (nid=1 80000000 - c7e60000) (1000000 - ffffffffffffffff) 240 40 => 80000000
[    0.000000] BUG: unable to handle kernel paging request at 40000000
[    0.000000] IP: [<c2c8cff1>] __alloc_memory_core_early+0x147/0x1d6
[    0.000000] *pdpt = 0000000000000000 *pde = f000ff53f000ff00
...
[    0.000000] Call Trace:
[    0.000000]  [<c2c8b4f8>] ? __alloc_bootmem_node+0x216/0x22f
[    0.000000]  [<c2c90c9b>] ? sparse_early_usemaps_alloc_node+0x5a/0x10b
[    0.000000]  [<c2c9149e>] ? sparse_init+0x1dc/0x499
[    0.000000]  [<c2c79118>] ? paging_init+0x168/0x1df
[    0.000000]  [<c2c780ff>] ? native_pagetable_setup_start+0xef/0x1bb

looks like it allocates too much high address for bootmem.

Try to cut limit with get_max_mapped()
Reported-by: NBorislav Petkov <borislav.petkov@amd.com>
Tested-by: NConny Seidel <conny.seidel@amd.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>		[2.6.34.x]
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit e534c7c5 ("numa: x86_64: use generic percpu var
numa_node_id() implementation") broke numa systems that don't have ram
on node0 when MEMORY_HOTPLUG is enabled, because cpu_up() will call
cpu_to_node() before per_cpu(numa_node) is setup for APs.

When Node0 doesn't have RAM, on x86, cpus already round it to nearest
node with RAM in x86_cpu_to_node_map.  and per_cpu(numa_node) is not set
up until in c_init for APs.

When later cpu_up() calling cpu_to_node() will get 0 again, and make it
online even there is no RAM on node0.  so later all APs can not booted up,
and later will have panic.

[    1.611101] On node 0 totalpages: 0
.........
[    2.608558] On node 0 totalpages: 0
[    2.612065] Brought up 1 CPUs
[    2.615199] Total of 1 processors activated (3990.31 BogoMIPS).
...
   93.225341] calling  loop_init+0x0/0x1a4 @ 1
[   93.229314] PERCPU: allocation failed, size=80 align=8, failed to populate
[   93.246539] Pid: 1, comm: swapper Tainted: G        W   2.6.35-rc4-tip-yh-04371-gd64e6c4-dirty #354
[   93.264621] Call Trace:
[   93.266533]  [<ffffffff81125e43>] pcpu_alloc+0x83a/0x8e7
[   93.270710]  [<ffffffff81125f15>] __alloc_percpu+0x10/0x12
[   93.285849]  [<ffffffff8140786c>] alloc_disk_node+0x94/0x16d
[   93.291811]  [<ffffffff81407956>] alloc_disk+0x11/0x13
[   93.306157]  [<ffffffff81503e51>] loop_alloc+0xa7/0x180
[   93.310538]  [<ffffffff8277ef48>] loop_init+0x9b/0x1a4
[   93.324909]  [<ffffffff8277eead>] ? loop_init+0x0/0x1a4
[   93.329650]  [<ffffffff810001f2>] do_one_initcall+0x57/0x136
[   93.345197]  [<ffffffff827486d0>] kernel_init+0x184/0x20e
[   93.348146]  [<ffffffff81034954>] kernel_thread_helper+0x4/0x10
[   93.365194]  [<ffffffff81c7cc3c>] ? restore_args+0x0/0x30
[   93.369305]  [<ffffffff8274854c>] ? kernel_init+0x0/0x20e
[   93.386011]  [<ffffffff81034950>] ? kernel_thread_helper+0x0/0x10
[   93.392047] loop: out of memory
...

Try to assign per_cpu(numa_node) early

[akpm@linux-foundation.org: tidy up code comment]
Signed-off-by: NYinghai <yinghai@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Acked-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simply add a proper ID into the device table.
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Dave Jiang <djiang@mvista.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 5753c082 ("powerpc/85xx:
Kconfig cleanup"), there is no MPC85xx Kconfig symbol anymore, so the
driver became non-selectable.

This patch fixes the issue by switching to PPC_85xx symbol.
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Dave Jiang <djiang@mvista.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need lock_page_nosync() here because we have no reference to the
mapping when taking the page lock.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The last change to improve the scalability moved the actual wake-up out of
the section that is protected by spin_lock(sma->sem_perm.lock).

This means that IN_WAKEUP can be in queue.status even when the spinlock is
acquired by the current task.  Thus the same loop that is performed when
queue.status is read without the spinlock acquired must be performed when
the spinlock is acquired.

Thanks to kamezawa.hiroyu@jp.fujitsu.com for noticing lack of the memory
barrier.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16255

[akpm@linux-foundation.org: clean up kerneldoc, checkpatch warning and whitespace]
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Reported-by: NLuca Tettamanti <kronos.it@gmail.com>
Tested-by: NLuca Tettamanti <kronos.it@gmail.com>
Reported-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.infradead.org/users/cbou/battery-2.6.35:
  ds2782_battery: Fix ds2782_get_capacity return value

The new netpoll code in bridging contains use-after-free bugs
that are non-trivial to fix.

This patch fixes this by removing the code that uses skbs after
they're freed.

As a consequence, this means that we can no longer call bridge
from the netpoll path, so this patch also removes the controller
function in order to disable netpoll.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Thanks,
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* 'shrinker' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev:
  xfs: track AGs with reclaimable inodes in per-ag radix tree
  xfs: convert inode shrinker to per-filesystem contexts
  mm: add context argument to shrinker callback

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix checks in BTRFS_IOC_CLONE_RANGE
  Btrfs: fix CLONE ioctl destination file size expansion to block boundary
  Btrfs: fix split_leaf double split corner case

https://bugzilla.kernel.org/show_bug.cgi?id=16348

When the filesystem grows to a large number of allocation groups,
the summing of recalimable inodes gets expensive. In many cases,
most AGs won't have any reclaimable inodes and so we are wasting CPU
time aggregating over these AGs. This is particularly important for
the inode shrinker that gets called frequently under memory
pressure.

To avoid the overhead, track AGs with reclaimable inodes in the
per-ag radix tree so that we can find all the AGs with reclaimable
inodes via a simple gang tag lookup. This involves setting the tag
when the first reclaimable inode is tracked in the AG, and removing
the tag when the last reclaimable inode is removed from the tree.
Then the summation process becomes a loop walking the radix tree
summing AGs with the reclaim tag set.

This significantly reduces the overhead of scanning - a 6400 AG
filesystea now only uses about 25% of a cpu in kswapd while slab
reclaim progresses instead of being permanently stuck at 100% CPU
and making little progress. Clean filesystems filesystems will see
no overhead and the overhead only increases linearly with the number
of dirty AGs.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Now the shrinker passes us a context, wire up a shrinker context per
filesystem. This allows us to remove the global mount list and the
locking problems that introduced. It also means that a shrinker call
does not need to traverse clean filesystems before finding a
filesystem with reclaimable inodes.  This significantly reduces
scanning overhead when lots of filesystems are present.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

1.  The BTRFS_IOC_CLONE and BTRFS_IOC_CLONE_RANGE ioctls should check
whether the donor file is append-only before writing to it.

2.  The BTRFS_IOC_CLONE_RANGE ioctl appears to have an integer
overflow that allows a user to specify an out-of-bounds range to copy
from the source file (if off + len wraps around).  I haven't been able
to successfully exploit this, but I'd imagine that a clever attacker
could use this to read things he shouldn't.  Even if it's not
exploitable, it couldn't hurt to be safe.
Signed-off-by: NDan Rosenberg <dan.j.rosenberg@gmail.com>
cc: stable@kernel.org
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain
  x86: Fix x2apic preenabled system with kexec
  x86: Force HPET readback_cmp for all ATI chipsets

* 'kmemleak' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm:
  kmemleak: Add support for NO_BOOTMEM configurations
  kmemleak: Annotate false positive in init_section_page_cgroup()

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] cio: fix potential overflow in chpid descriptor
  [S390] add missing device put
  [S390] dasd: use correct label location for diag fba disks

- fix reversing of command/sub arguments
- fix a crash if the i2c interface is called before the device is found
Signed-off-by: NSreedhara DS <sreedhara.ds@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The CLONE and CLONE_RANGE ioctls round up the range of extents being
cloned to the block size when the range to clone extends to the end of file
(this is always the case with CLONE).  It was then using that offset when
extending the destination file's i_size.  Fix this by not setting i_size
beyond the originally requested ending offset.

This bug was introduced by a22285a6 (2.6.35-rc1).
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

split_leaf was not properly balancing leaves when it was forced to
split a leaf twice.  This commit adds an extra push left and right
before forcing the double split in hopes of getting the slot where
we want to insert at either the start or end of the leaf.

If the extra pushes do work, then we are able to avoid splitting twice
and we keep the tree properly balanced.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

It can happen that there are no packets in queue while calling
tcp_xmit_retransmit_queue(). tcp_write_queue_head() then returns
NULL and that gets deref'ed to get sacked into a local var.

There is no work to do if no packets are outstanding so we just
exit early.

This oops was introduced by 08ebd172 (tcp: remove tp->lost_out
guard to make joining diff nicer).
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Reported-by: NLennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Tested-by: NLennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With commits 08677214 and 59be5a8e, alloc_bootmem()/free_bootmem() and
friends use the early_res functions for memory management when
NO_BOOTMEM is enabled. This patch adds the kmemleak calls in the
corresponding code paths for bootmem allocations.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org

The pointer to the page_cgroup table allocated in
init_section_page_cgroup() is stored in section->page_cgroup as (base -
pfn). Since this value does not point to the beginning or inside the
allocated memory block, kmemleak reports a false positive.

This was reported in bugzilla.kernel.org as #16297.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NAdrien Dessemond <adrien.dessemond@gmail.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>

The length filed in the chsc response block (if valid)
has a value of n*(sizeof(chp_desc))+8 (for the response
block header). When we memcopied from the response block
to the actual descriptor we copied 8 bytes too much.
The bug was not revealed since the descriptor is embedded
in struct channel_path.
Since we only write one descriptor at a time ignore the
length value and use sizeof(*desc).
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The dasd_alias_show function does not return a device reference
in case the device is an alias.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Partition boundary calculation fails for DASD FBA disks under the
following conditions:
- disk is formatted with CMS FORMAT with a blocksize of more than
  512 bytes
- all of the disk is reserved to a single CMS file using CMS RESERVE
- the disk is accessed using the DIAG mode of the DASD driver

Under these circumstances, the partition detection code tries to
read the CMS label block containing partition-relevant information
from logical block offset 1, while it is in fact located at physical
block offset 1.

Fix this problem by using the correct CMS label block location
depending on the device type as determined by the DASD SENSE ID
information.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

* 'x86/kprobes' of git://git.kernel.org/pub/scm/linux/kernel/git/frob/linux-2.6-roland:
  x86: kprobes: fix swapped segment registers in kretprobe

In commit f007ea26, the order of the %es and %ds segment registers
got accidentally swapped, so synthesized 'struct pt_regs' frames
have the two values inverted.  It's almost sure that these values
never matter, and that they also never differ.  But wrong is wrong.
Signed-off-by: NRoland McGrath <roland@redhat.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: fall back to original BIOS BAR addresses

The input handler for Type 2 Routing Header (mip6_rthdr_input())
checks if the CoA in the packet matches the CoA in the XFRM state.

Current check is buggy: it compares the adddress in the Type 2
Routing Header, i.e. the HoA, against the expected CoA in the state.
The comparison should be made against the address in the destination
field of the IPv6 header.

The bug remained unnoticed because the main (and possibly only current)
user of the code (UMIP MIPv6 Daemon) initializes the XFRM state with the
unspecified address, i.e. explicitly allows everything.

Yoshifuji-san, can you ack that one?
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
  ocfs2: Silence gcc warning in ocfs2_write_zero_page().
  jbd2/ocfs2: Fix block checksumming when a buffer is used in several transactions
  ocfs2/dlm: Remove BUG_ON from migration in the rare case of a down node
  ocfs2: Don't duplicate pages past i_size during CoW.
  ocfs2: tighten up strlen() checking
  ocfs2: Make xattr reflink work with new local alloc reservation.
  ocfs2: make xattr extension work with new local alloc reservation.
  ocfs2: Remove the redundant cpu_to_le64.
  ocfs2/dlm: don't access beyond bitmap size
  ocfs2: No need to zero pages past i_size.
  ocfs2: Zero the tail cluster when extending past i_size.
  ocfs2: When zero extending, do it by page.
  ocfs2: Limit default local alloc size within bitmap range.
  ocfs2: Move orphan scan work to ocfs2_wq.
  fs/ocfs2/dlm: Add missing spin_unlock

The hibernate issues that got fixed in commit 985b823b ("drm/i915:
fix hibernation since i915 self-reclaim fixes") turn out to have been
incomplete.  Vefa Bicakci tested lots of hibernate cycles, and without
the __GFP_RECLAIMABLE flag the system eventually fails to resume.

With the flag added, Vefa can apparently hibernate forever (or until he
gets bored running his automated scripts, whichever comes first).

The reclaimable flag was there originally, and was one of the flags that
were dropped (unintentionally) by commit 4bdadb97 ("drm/i915:
Selectively enable self-reclaim") that introduced all these problems,
but I didn't want to just blindly add back all the flags in commit
985b823b, and it looked like __GFP_RECLAIM wasn't necessary.  It
clearly was.

I still suspect that there is some subtle reason we're missing that
causes the problems, but __GFP_RECLAIMABLE is certainly not wrong to use
in this context, and is what the code historically used.  And we have no
idea what the causes the corruption without it.
Reported-and-tested-by: NM. Vefa Bicakci <bicave@superonline.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The fixed bar capability structure is searched in PCI extended
configuration space.  We need to make sure there is a valid capability
ID to begin with otherwise, the search code may stuck in a infinite
loop which results in boot hang.  This patch adds additional check for
cap ID 0, which is also invalid, and indicates end of chain.

End of chain is supposed to have all fields zero, but that doesn't
seem to always be the case in the field.
Suggested-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <1279306706-27087-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Found one x2apic system kexec loop test failed
when CONFIG_NMI_WATCHDOG=y (old) or CONFIG_LOCKUP_DETECTOR=y (current tip)

first kernel can kexec second kernel, but second kernel can not kexec third one.

it can be duplicated on another system with BIOS preenabled x2apic.
First kernel can not kexec second kernel.

It turns out, when kernel boot with pre-enabled x2apic, it will not execute
disable_local_APIC on shutdown path.

when init_apic_mappings() is called in setup_arch, it will skip setting of
apic_phys when x2apic_mode is set. ( x2apic_mode is much early check_x2apic())
Then later, disable_local_APIC() will bail out early because !apic_phys.

So check !x2apic_mode in x2apic_mode in disable_local_APIC with !apic_phys.

another solution could be updating init_apic_mappings() to set apic_phys even
for preenabled x2apic system. Actually even for x2apic system, that lapic
address is mapped already in early stage.

BTW: is there any x2apic preenabled system with apicid of boot cpu > 255?
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C3EB22B.3000701@kernel.org>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: stable@kernel.org
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

ocfs2_write_zero_page() has a loop that won't ever be skipped, but gcc
doesn't know that.  Set ret=0 just to make gcc happy.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>