* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  af_key: Free dumping state on socket close
  XFRM,IPv6: initialize ip6_dst_blackhole_ops.kmem_cachep
  ipv6: NULL pointer dereferrence in tcp_v6_send_ack
  tcp: Fix NULL dereference in tcp_4_send_ack()
  sctp: Fix kernel panic while process protocol violation parameter
  iucv: Fix mismerge again.
  ipsec: Fix pskb_expand_head corruption in xfrm_state_check_space

Fix a xfrm_{state,policy}_walk leak if pfkey socket is closed while
dumping is on-going.
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6_dst_blackhole_ops.kmem_cachep is not expected to be NULL (i.e. to
be initialized) when dst_alloc() is called from ip6_dst_blackhole().
Otherwise, it results in the following (xfrm_larval_drop is now set to
1 by default):

[   78.697642] Unable to handle kernel paging request for data at address 0x0000004c
[   78.703449] Faulting instruction address: 0xc0097f54
[   78.786896] Oops: Kernel access of bad area, sig: 11 [#1]
[   78.792791] PowerMac
[   78.798383] Modules linked in: btusb usbhid bluetooth b43 mac80211 cfg80211 ehci_hcd ohci_hcd sungem sungem_phy usbcore ssb
[   78.804263] NIP: c0097f54 LR: c0334a28 CTR: c002d430
[   78.809997] REGS: eef19ad0 TRAP: 0300   Not tainted  (2.6.27-rc5)
[   78.815743] MSR: 00001032 <ME,IR,DR>  CR: 22242482  XER: 20000000
[   78.821550] DAR: 0000004c, DSISR: 40000000
[   78.827278] TASK = eef0df40[3035] 'mip6d' THREAD: eef18000
[   78.827408] GPR00: 00001032 eef19b80 eef0df40 00000000 00008020 eef19c30 00000001 00000000
[   78.833249] GPR08: eee5101c c05a5c10 ef9ad500 00000000 24242422 1005787c 00000000 1004f960
[   78.839151] GPR16: 00000000 10024e90 10050040 48030018 0fe44150 00000000 00000000 eef19c30
[   78.845046] GPR24: eef19e44 00000000 eef19bf8 efb37c14 eef19bf8 00008020 00009032 c0596064
[   78.856671] NIP [c0097f54] kmem_cache_alloc+0x20/0x94
[   78.862581] LR [c0334a28] dst_alloc+0x40/0xc4
[   78.868451] Call Trace:
[   78.874252] [eef19b80] [c03c1810] ip6_dst_lookup_tail+0x1c8/0x1dc (unreliable)
[   78.880222] [eef19ba0] [c0334a28] dst_alloc+0x40/0xc4
[   78.886164] [eef19bb0] [c03cd698] ip6_dst_blackhole+0x28/0x1cc
[   78.892090] [eef19be0] [c03d9be8] rawv6_sendmsg+0x75c/0xc88
[   78.897999] [eef19cb0] [c038bca4] inet_sendmsg+0x4c/0x78
[   78.903907] [eef19cd0] [c03207c8] sock_sendmsg+0xac/0xe4
[   78.909734] [eef19db0] [c03209e4] sys_sendmsg+0x1e4/0x2a0
[   78.915540] [eef19f00] [c03220a8] sys_socketcall+0xfc/0x210
[   78.921406] [eef19f40] [c0014b3c] ret_from_syscall+0x0/0x38
[   78.927295] --- Exception: c01 at 0xfe2d730
[   78.927297]     LR = 0xfe2d71c
[   78.939019] Instruction dump:
[   78.944835] 91640018 9144001c 900a0000 4bffff44 9421ffe0 7c0802a6 bf810010 7c9d2378
[   78.950694] 90010024 7fc000a6 57c0045e 7c000124 <83e3004c> 8383005c 2f9f0000 419e0050
[   78.956464] ---[ end trace 05fa1ed7972487a1 ]---

As commented by Benjamin Thery, the bug was introduced by
f2fc6a54, while adding network
namespaces support to ipv6 routes.
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The following actions are possible:
tcp_v6_rcv
  skb->dev = NULL;
  tcp_v6_do_rcv
    tcp_v6_hnd_req
      tcp_check_req
        req->rsk_ops->send_ack == tcp_v6_send_ack

So, skb->dev can be NULL in tcp_v6_send_ack. We must obtain namespace
from dst entry.

Thanks to Vitaliy Gusev <vgusev@openvz.org> for initial problem finding
in IPv4 code.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix NULL dereference in tcp_4_send_ack().

As skb->dev is reset to NULL in tcp_v4_rcv() thus OOPS occurs:

BUG: unable to handle kernel NULL pointer dereference at 00000000000004d0
IP: [<ffffffff80498503>] tcp_v4_send_ack+0x203/0x250

Stack:  ffff810005dbb000 ffff810015c8acc0 e77b2c6e5f861600 a01610802e90cb6d
 0a08010100000000 88afffff88afffff 0000000080762be8 0000000115c872e8
 0004122000000000 0000000000000001 ffffffff80762b88 0000000000000020
Call Trace:
 <IRQ>  [<ffffffff80499c33>] tcp_v4_reqsk_send_ack+0x20/0x22
 [<ffffffff8049bce5>] tcp_check_req+0x108/0x14c
 [<ffffffff8047aaf7>] ? rt_intern_hash+0x322/0x33c
 [<ffffffff80499846>] tcp_v4_do_rcv+0x399/0x4ec
 [<ffffffff8045ce4b>] ? skb_checksum+0x4f/0x272
 [<ffffffff80485b74>] ? __inet_lookup_listener+0x14a/0x15c
 [<ffffffff8049babc>] tcp_v4_rcv+0x6a1/0x701
 [<ffffffff8047e739>] ip_local_deliver_finish+0x157/0x24a
 [<ffffffff8047ec9a>] ip_local_deliver+0x72/0x7c
 [<ffffffff8047e5bd>] ip_rcv_finish+0x38d/0x3b2
 [<ffffffff803d3548>] ? scsi_io_completion+0x19d/0x39e
 [<ffffffff8047ebe5>] ip_rcv+0x2a2/0x2e5
 [<ffffffff80462faa>] netif_receive_skb+0x293/0x303
 [<ffffffff80465a9b>] process_backlog+0x80/0xd0
 [<ffffffff802630b4>] ? __rcu_process_callbacks+0x125/0x1b4
 [<ffffffff8046560e>] net_rx_action+0xb9/0x17f
 [<ffffffff80234cc5>] __do_softirq+0xa3/0x164
 [<ffffffff8020c52c>] call_softirq+0x1c/0x28
 <EOI>  [<ffffffff8020de1c>] do_softirq+0x34/0x72
 [<ffffffff80234b8e>] local_bh_enable_ip+0x3f/0x50
 [<ffffffff804d43ca>] _spin_unlock_bh+0x12/0x14
 [<ffffffff804599cd>] release_sock+0xb8/0xc1
 [<ffffffff804a6f9a>] inet_stream_connect+0x146/0x25c
 [<ffffffff80243078>] ? autoremove_wake_function+0x0/0x38
 [<ffffffff8045751f>] sys_connect+0x68/0x8e
 [<ffffffff80291818>] ? fd_install+0x5f/0x68
 [<ffffffff80457784>] ? sock_map_fd+0x55/0x62
 [<ffffffff8020b39b>] system_call_after_swapgs+0x7b/0x80

Code: 41 10 11 d0 83 d0 00 4d 85 ed 89 45 c0 c7 45 c4 08 00 00 00 74 07 41 8b 45 04 89 45 c8 48 8b 43 20 8b 4d b8 48 8d 55 b0 48 89 de <48> 8b 80 d0 04 00 00 48 8b b8 60 01 00 00 e8 20 ae fe ff 65 48
RIP  [<ffffffff80498503>] tcp_v4_send_ack+0x203/0x250
 RSP <ffffffff80762b78>
CR2: 00000000000004d0
Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

After investigating a JRE failure, I found this bug was introduced a
long time ago, and had already managed to survive another bugfix which
occurred on the same line.  The result is a total failure of the JRE due
to LDT selectors not working properly.

This one took a long time to rear up because LDT usage is not very
common, but the bug is quite serious.  It got introduced along with
another bug, already fixed, by 75b8bb3eSigned-off-by: Zachary Amsden <zach@vmware.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Put the space for cpu0 per-cpu area into .data section

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Fix model for Dell Inspiron 1525
  ALSA: ASoC: Fix cs4270 error path

* 'for-linus' of git://git.o-hand.com/linux-mfd:
  mfd: Fix asic3 compilation
  mfd: Fix Kconfig accroding to the new gpiolib symbols

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix failure to shutdown with CPU hotplug
  powerpc: Fix PCI in Holly device tree

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

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: prevent migration of per CPU hrtimers
  hrtimer: mark migration state
  hrtimer: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimers
  hrtimer: migrate pending list on cpu offline
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Since call to function sctp_sf_abort_violation() need paramter 'arg' with
'struct sctp_chunk' type, it will read the chunk type and chunk length from
the chunk_hdr member of chunk. But call to sctp_sf_violation_paramlen()
always with 'struct sctp_paramhdr' type's parameter, it will be passed to
sctp_sf_abort_violation(). This may cause kernel panic.

   sctp_sf_violation_paramlen()
     |-- sctp_sf_abort_violation()
        |-- sctp_make_abort_violation()

This patch fixed this problem. This patch also fix two place which called
sctp_sf_violation_paramlen() with wrong paramter type.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dell Inspiron 1525 seems to have a buggy BIOS setup and screws up
the recent codec parser, as reported by Oleksandr Natalenko:
    http://lkml.org/lkml/2008/9/12/203

This patch adds the working model, dell-3stack, statically.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>

The error path in cs4270_probe/cs4270_remove is pretty broken:
* If cs4270_probe fails, codec is leaked.
* If snd_soc_register_card fails, cs4270_i2c_driver stays registered.
* If I2C support is enabled but no I2C device is found, i2c_del_driver
  is never called (neither in cs4270_probe nor in cs4270_remove.

Fix all 3 problems by implementing a clean error path in cs4270_probe
and jumping to its labels as needed.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

fb65a7c0 ("iucv: Fix bad merging.") fixed
a merge error, but in a wrong way. We now end up with the bug below.
This patch corrects the mismerge like it was intended.

BUG: scheduling while atomic: swapper/1/0x00000000
Modules linked in:
CPU: 1 Not tainted 2.6.27-rc7-00094-gc0f4d6d4 #9
Process swapper (pid: 1, task: 000000003fe7d988, ksp: 000000003fe838c0)
0000000000000000 000000003fe839b8 0000000000000002 0000000000000000
       000000003fe83a58 000000003fe839d0 000000003fe839d0 0000000000390de6
       000000000058acd8 00000000000000d0 000000003fe7dcd8 0000000000000000
       000000000000000c 000000000000000d 0000000000000000 000000003fe83a28
       000000000039c5b8 0000000000015e5e 000000003fe839b8 000000003fe83a00
Call Trace:
([<0000000000015d6a>] show_trace+0xe6/0x134)
 [<0000000000039656>] __schedule_bug+0xa2/0xa8
 [<0000000000391744>] schedule+0x49c/0x910
 [<0000000000391f64>] schedule_timeout+0xc4/0x114
 [<00000000003910d4>] wait_for_common+0xe8/0x1b4
 [<00000000000549ae>] call_usermodehelper_exec+0xa6/0xec
 [<00000000001af7b8>] kobject_uevent_env+0x418/0x438
 [<00000000001d08fc>] bus_add_driver+0x1e4/0x298
 [<00000000001d1ee4>] driver_register+0x90/0x18c
 [<0000000000566848>] netiucv_init+0x168/0x2c8
 [<00000000000120be>] do_one_initcall+0x3e/0x17c
 [<000000000054a31a>] kernel_init+0x1ce/0x248
 [<000000000001a97a>] kernel_thread_starter+0x6/0xc
 [<000000000001a974>] kernel_thread_starter+0x0/0xc
 iucv: NETIUCV driver initialized
initcall netiucv_init+0x0/0x2c8 returned with preemption imbalance
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We're never supposed to shrink the headroom or tailroom.  In fact,
shrinking the headroom is a fatal action.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

map_size was declared from the wrong place.
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

HAVE_GPIO_LIB has basically been replaced by GPIOLIB
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

I tracked down the shutdown regression to CPUs not dying
when being shut down during power-off. This turns out to
be due to the system_state being SYSTEM_POWER_OFF, which
this code doesn't take as a valid state for shutting off
CPUs in.

This has never made sense to me, but when I added hotplug
code to implement hibernate I only "made it work" and did
not question the need to check the system_state. Thomas
Gleixner helped me dig, but the only thing we found is
that it was added with the original commit that added CPU
hotplug support.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Joel Schopp <jschopp@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The PCI bridge on the Holly board is incorrectly represented in the
device tree.  The current device tree node for the PCI bridge sits
under the tsi-bridge node.  That's not obviously wrong, but the PCI
bridge translates some PCI spaces into CPU address ranges which were
not translated by the "ranges" property in tsi-bridge node.

We used to get away with this problem because the PCI bridge discovery
code was also buggy, assuming incorrectly that PCI host bridge nodes
were always directly under the root bus and treating the translated
addresses as raw CPU addresses, rather than parent bus addresses.
This has since been fixed, thus breaking Holly.

This could be fixed by adding extra translations to the tsi-bridge
node, but this patch instead moves the Holly PCI bridge out of the
tsi-bridge node to the root bus.  This makes the tsi-bridge node
represent only the built-in IO devices in the bridge, with a
more-or-less contiguous address range.  This is the same convention
used on Freescale SoC chips, where the "soc" node represents only the
IMMR region, and the PCI and other bus bridges are separate nodes
under the root bus.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Initial fix for making sure that we can access percpu variables
in all C code (commit: 10617bbe)
inadvertantly allocated the memory in the "percpu" section of
the vmlinux ELF executable.  This confused kexec/dump.
Signed-off-by: Tony Luck <tony.luck@intel.com>

There's a race between mm->owner assignment and swapoff, more easily
seen when task slab poisoning is turned on.  The condition occurs when
try_to_unuse() runs in parallel with an exiting task.  A similar race
can occur with callers of get_task_mm(), such as /proc/<pid>/<mmstats>
or ptrace or page migration.

CPU0                                    CPU1
                                        try_to_unuse
                                        looks at mm = task0->mm
                                        increments mm->mm_users
task 0 exits
mm->owner needs to be updated, but no
new owner is found (mm_users > 1, but
no other task has task->mm = task0->mm)
mm_update_next_owner() leaves
                                        mmput(mm) decrements mm->mm_users
task0 freed
                                        dereferencing mm->owner fails

The fix is to notify the subsystem via mm_owner_changed callback(),
if no new owner is found, by specifying the new task as NULL.

Jiri Slaby:
mm->owner was set to NULL prior to calling cgroup_mm_owner_callbacks(), but
must be set after that, so as not to pass NULL as old owner causing oops.

Daisuke Nishimura:
mm_update_next_owner() may set mm->owner to NULL, but mem_cgroup_from_task()
and its callers need to take account of this situation to avoid oops.

Hugh Dickins:
Lockdep warning and hang below exec_mmap() when testing these patches.
exit_mm() up_reads mmap_sem before calling mm_update_next_owner(),
so exec_mmap() now needs to do the same.  And with that repositioning,
there's now no point in mm_need_new_owner() allowing for NULL mm.
Reported-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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: disable apm on the olpc

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  cdrom: update ioctl documentation
  ide: note that IDE generic may prevent other drivers from attaching
  ide-tape: fix vendor strings
  Swarm: Fix crash due to missing initialization

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [SSB] Initialise dma_mask for SSB_BUSTYPE_SSB devices
  [MIPS] BCM47xx: Fix build error due to missing PCI functions
  [MIPS] IP27: Switch to dynamic interrupt routing avoding panic on error.
  [MIPS] au1000: Make sure GPIO value is zero or one

* 'linux-m32r' of git://www.linux-m32r.org/git/takata/linux-2.6_dev:
  m32r/kernel/: cleanups
  m32r: export __ndelay
  m32r: export empty_zero_page
  m32r: don't offer CONFIG_ISA
  m32r: remove the unused NOHIGHMEM option

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdboc,tty: Fix tty polling search to use name correctly
  kgdb, x86_64: fix PS CS SS registers in gdb serial
  kgdb, x86_64: gdb serial has BX and DX reversed
  kgdb, x86, arm, mips, powerpc: ignore user space single stepping
  kgdb: could not write to the last of valid memory with kgdb

Impact: per CPU hrtimers can be migrated from a dead CPU

The hrtimer code has no knowledge about per CPU timers, but we need to
prevent the migration of such timers and warn when such a timer is
active at migration time.

Explicitely mark the timers as per CPU and use a more understandable
mode descriptor for the interrupts safe unlocked callback mode, which
is used by hrtimer_sleeper and the scheduler code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Impact: during migration active hrtimers can be seen as inactive

The migration code removes the hrtimers from the queues of the dead
CPU and sets the state temporary to INACTIVE. The enqueue code sets it
to ACTIVE/PENDING again.

Prevent that the wrong state can be seen by using a separate migration
state bit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Impact: Stale timers after a CPU went offline.

commit 37bb6cb4
       hrtimer: unlock hrtimer_wakeup

changed the hrtimer sleeper callback mode to CB_IRQSAFE_NO_SOFTIRQ due
to locking problems. A result of this change is that when enqueue is
called for an already expired hrtimer the callback function is not
longer called directly from the enqueue code. The normal callers have
been fixed in the code, but the migration code which moves hrtimers
from a dead CPU to a live CPU was not made aware of this.

This can be fixed by checking the timer state after the call to
enqueue in the migration code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Impact: hrtimers which are on the pending list are not migrated at cpu
	offline and can be stale forever

Add the pending list migration when CONFIG_HIGH_RES_TIMERS is enabled
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: ASoC: Fix another cs4270 error path
  ALSA: make the CS4270 driver a new-style I2C driver

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] qlogicpti: fix sg list traversal error in continuation entries
  [SCSI] Fix hang with split requests
  [SCSI] qla2xxx: Defer enablement of RISC interrupts until ISP initialization completes.

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  scsi: fix fall out of sg-chaining patch in qlogicpti

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_nv: reinstate nv_hardreset() for non generic controllers

Commit f072181e ("kconfig: drop the
""trying to assign nonexistent symbol" warning") simply dropped the
warnings, but it does a little more than that, it also marks the current
.config as needed saving, so add this back.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Recent changes to oldconfig have mixed up the silentoldconfig handling,
so this fixes that by clearly separating that special mode, e.g.
KCONFIG_NOSILENTUPDATE is only relevant here, the .config is written as
needed.

This will also properly close Bug 11230.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The VFS interface for the 'd_compare()' is a bit special (read: 'odd'),
because it really just essentially replaces a memcmp().  The filesystem
is supposed to just compare the two names with whatever case-independent
or other function.

And when I say 'is supposed to', I obviously mean that 'procfs does odd
things, and actually looks at the dentry that we don't even pass down,
rather than just the name'.  Which results in problems, because we
actually call d_compare before we have even verified that the dentry is
still hashed at all.

And that causes a problm since the inode that procfs looks at may have
been free'd and the d_inode pointer is NULL.  procfs just assumes that
all dentries are positive, since procfs itself never generates a
negative one.  But memory pressure will still result in the dentry
getting torn down, and as it is removed by RCU, it still remains visible
on some lists - and to d_compare.

If the filesystem just did a name comparison, we wouldn't care.  And we
could just fix procfs to know about negative dentries too.  But rather
than have the low-level filesystems know about internal VFS details,
just move the check for a unhashed dentry up a bit, so that we will only
call d_compare on dentries that are still active.

The actual oops this caused didn't look like a NULL pointer dereference
because procfs did a 'container_of(inode, struct proc_inode, vfs_inode)'
to get at its internal proc_inode information from the inode pointer,
and accessed a field below the inode. So the oops would look something
like

	BUG: unable to handle kernel paging request at fffffffffffffff0
	IP: [<ffffffff802bc6c6>] proc_sys_compare+0x36/0x50

and was seen on both x86-64 (Alexey Dobriyan and Hugh Dickins) and
ppc64 (Hugh Dickins).
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>

Conversion to new-style i2c driver missed the error path of the
probe function. Fix it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Timur Tabi <timur@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>