Use stack memory for pending entry to reduce kmalloc() which will be kfree()d.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

This reverts commit a674fa46.

Previous revert was a prereq.
Signed-off-by: James Morris <jmorris@namei.org>

This reverts commit b89e66e1.

> > When CONFIG_PM is not set:
> >
> > drivers/built-in.o: In function `acpi_init':
> > bus.c:(.init.text+0x2d84): undefined reference to `pm_flags'
> > bus.c:(.init.text+0x2d91): undefined reference to `pm_flags'
>
> CONFIG_ACPI depends on CONFIG_PM,
> so acpi/bus.c should not be compiled for CONFIG_PM=n
>
> Hmm, is is somebody doing something strange, like "select ACPI"
> without guaranteeing that all of ACPI's dependencies are satisfied?
Signed-off-by: James Morris <jmorris@namei.org>

Do preallocation for __key_link() so that the various callers in request_key.c
can deal with any errors from this source before attempting to construct a key.
This allows them to assume that the actual linkage step is guaranteed to be
successful.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

Conflicts:
	security/keys/keyring.c

Resolved conflict with whitespace fix in find_keyring_by_name()
Signed-off-by: James Morris <jmorris@namei.org>

Some of TOMOYO's functions may sleep after mutex_lock(). If OOM-killer selected
a process which is waiting at mutex_lock(), the to-be-killed process can't be
killed. Thus, replace mutex_lock() with mutex_lock_interruptible() so that the
to-be-killed process can immediately return from TOMOYO's functions.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

Errors from construct_alloc_key() shouldn't just be ignored in the way they are
by construct_key_and_link().  The only error that can be ignored so is
EINPROGRESS as that is used to indicate that we've found a key and don't need
to construct one.

We don't, however, handle ENOMEM, EDQUOT or EACCES to indicate allocation
failures of one sort or another.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

keyring_serialise_link_sem is only needed for keyring->keyring links as it's
used to prevent cycle detection from being avoided by parallel keyring
additions.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

* 'zerolen' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6:
  [MTD] Remove zero-length files mtdbdi.c and internal.ho

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  pata_pcmcia / ide-cs: Fix bad hashes for Transcend and kingston IDs
  libata: Fix several inaccuracies in developer's guide

Both were "removed" in commit a33eb6b9.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

This patch fixes the bad hashes for one Kingston and one Transcend card.
Thanks to komuro for pointing this out.
Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Commit 6bfff31e (libata: kill probe_ent
and related helpers) killed ata_device_add() but didn't remove references
to it from the libata developer's guide.

Commits 9363c382 (libata: rename SFF
functions) and 5682ed33 (libata: rename
SFF port ops) renamed the taskfile access methods but didn't update the
developer's guide.  Commit c9f75b04
(libata: kill ata_noop_dev_select()) didn't update the developer's
guide as well.

The guide also refers to the long gone ata_pio_data_xfer_noirq(),
ata_pio_data_xfer(), and ata_mmio_data_xfer() -- replace those by
the modern ata_sff_data_xfer_noirq(), ata_sff_data_xfer(), and
ata_sff_data_xfer32().

Also, remove the reference to non-existant ata_port_stop()...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

* 'slab-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Fix bad boundary check in init_kmem_cache_nodes()

Function init_kmem_cache_nodes is incorrect when checking upper limitation of
kmalloc_caches. The breakage was introduced by commit
91efd773 ("dma kmalloc handling fixes").
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  KEYS: call_sbin_request_key() must write lock keyrings before modifying them
  KEYS: Use RCU dereference wrappers in keyring key type code
  KEYS: find_keyring_by_name() can gain access to a freed keyring

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: flush_delayed_work: keep the original workqueue for re-queueing

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  FEC: Fix kernel panic in fec_set_mac_address.
  ipv6: Fix default multicast hops setting.
  net: ep93xx_eth stops receiving packets
  drivers/net/phy: micrel phy driver
  dm9601: fix phy/eeprom write routine
  ppp_generic: handle non-linear skbs when passing them to pppd
  ppp_generic: pull 2 bytes so that PPP_PROTO(skb) is valid
  net: fix compile error due to double return type in SOCK_DEBUG
  net/usb: initiate sync sequence in sierra_net.c driver
  net/usb: remove default in Kconfig for sierra_net driver
  r8169: Fix rtl8169_rx_interrupt()
  e1000e: Fix oops caused by ASPM patch.
  net/sb1250: register mdio bus in probe
  sctp: Fix skb_over_panic resulting from multiple invalid parameter errors (CVE-2010-1173) (v4)
  p54pci: fix bugs in p54p_check_tx_ring

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda: Fix 0 dB for Packard Bell models using Conexant CX20549 (Venice)
  ALSA: hda - Add quirk for Dell Inspiron 19T using a Conexant CX20582
  ALSA: take tu->qlock with irqs disabled
  ALSA: hda: Use olpc-xo-1_5 quirk for Toshiba Satellite P500-PSPGSC-01800T
  ALSA: hda: Use olpc-xo-1_5 quirk for Toshiba Satellite Pro T130-15F
  ALSA: hda - fix array indexing while creating inputs for Cirrus codecs
  ALSA: es968: fix wrong PnP dma index

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: joydev - allow binding to button-only devices
  Input: elantech - ignore high bits in the position coordinates
  Input: elantech - allow forcing Elantech protocol
  Input: elantech - fix firmware version check
  Input: ati_remote - add some missing devices from lirc_atiusb
  Input: eeti_ts - cancel pending work when going to suspend
  Input: Add support of Synaptics Clickpad device
  Revert "Input: ALPS - add signature for HP Pavilion dm3 laptops"
  Input: psmouse - ignore parity error for basic protocols

The raid6 recovery code should immediately drop back to the optimized
synchronous path when a p+q dma resource is not available.  Otherwise we
run the non-optimized/multi-pass async code in sync mode.

Verified with raid6test (NDISKS=255)

Applies to kernels >= 2.6.32.

Cc: <stable@kernel.org>
Acked-by: NeilBrown <neilb@suse.de>
Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In Ubuntu, security_path_*() hooks are exported to Unionfs. Thus, prepare for
being called from inside VFS functions because I'm not sure whether it is safe
to use GFP_KERNEL or not.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

call_sbin_request_key() creates a keyring and then attempts to insert a link to
the authorisation key into that keyring, but does so without holding a write
lock on the keyring semaphore.

It will normally get away with this because it hasn't told anyone that the
keyring exists yet.  The new keyring, however, has had its serial number
published, which means it can be accessed directly by that handle.

This was found by a previous patch that adds RCU lockdep checks to the code
that reads the keyring payload pointer, which includes a check that the keyring
semaphore is actually locked.

Without this patch, the following command:

	keyctl request2 user b a @s

will provoke the following lockdep warning is displayed in dmesg:

	===================================================
	[ INFO: suspicious rcu_dereference_check() usage. ]
	---------------------------------------------------
	security/keys/keyring.c:727 invoked rcu_dereference_check() without protection!

	other info that might help us debug this:

	rcu_scheduler_active = 1, debug_locks = 0
	2 locks held by keyctl/2076:
	 #0:  (key_types_sem){.+.+.+}, at: [<ffffffff811a5b29>] key_type_lookup+0x1c/0x71
	 #1:  (keyring_serialise_link_sem){+.+.+.}, at: [<ffffffff811a6d1e>] __key_link+0x4d/0x3c5

	stack backtrace:
	Pid: 2076, comm: keyctl Not tainted 2.6.34-rc6-cachefs #54
	Call Trace:
	 [<ffffffff81051fdc>] lockdep_rcu_dereference+0xaa/0xb2
	 [<ffffffff811a6d1e>] ? __key_link+0x4d/0x3c5
	 [<ffffffff811a6e6f>] __key_link+0x19e/0x3c5
	 [<ffffffff811a5952>] ? __key_instantiate_and_link+0xb1/0xdc
	 [<ffffffff811a59bf>] ? key_instantiate_and_link+0x42/0x5f
	 [<ffffffff811aa0dc>] call_sbin_request_key+0xe7/0x33b
	 [<ffffffff8139376a>] ? mutex_unlock+0x9/0xb
	 [<ffffffff811a5952>] ? __key_instantiate_and_link+0xb1/0xdc
	 [<ffffffff811a59bf>] ? key_instantiate_and_link+0x42/0x5f
	 [<ffffffff811aa6fa>] ? request_key_auth_new+0x1c2/0x23c
	 [<ffffffff810aaf15>] ? cache_alloc_debugcheck_after+0x108/0x173
	 [<ffffffff811a9d00>] ? request_key_and_link+0x146/0x300
	 [<ffffffff810ac568>] ? kmem_cache_alloc+0xe1/0x118
	 [<ffffffff811a9e45>] request_key_and_link+0x28b/0x300
	 [<ffffffff811a89ac>] sys_request_key+0xf7/0x14a
	 [<ffffffff81052c0b>] ? trace_hardirqs_on_caller+0x10c/0x130
	 [<ffffffff81394fb9>] ? trace_hardirqs_on_thunk+0x3a/0x3f
	 [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

The keyring key type code should use RCU dereference wrappers, even when it
holds the keyring's key semaphore.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

find_keyring_by_name() can gain access to a keyring that has had its reference
count reduced to zero, and is thus ready to be freed.  This then allows the
dead keyring to be brought back into use whilst it is being destroyed.

The following timeline illustrates the process:

|(cleaner)                           (user)
|
| free_user(user)                    sys_keyctl()
|  |                                  |
|  key_put(user->session_keyring)     keyctl_get_keyring_ID()
|  ||	//=> keyring->usage = 0        |
|  |schedule_work(&key_cleanup_task)   lookup_user_key()
|  ||                                   |
|  kmem_cache_free(,user)               |
|  .                                    |[KEY_SPEC_USER_KEYRING]
|  .                                    install_user_keyrings()
|  .                                    ||
| key_cleanup() [<= worker_thread()]    ||
|  |                                    ||
|  [spin_lock(&key_serial_lock)]        |[mutex_lock(&key_user_keyr..mutex)]
|  |                                    ||
|  atomic_read() == 0                   ||
|  |{ rb_ease(&key->serial_node,) }     ||
|  |                                    ||
|  [spin_unlock(&key_serial_lock)]      |find_keyring_by_name()
|  |                                    |||
|  keyring_destroy(keyring)             ||[read_lock(&keyring_name_lock)]
|  ||                                   |||
|  |[write_lock(&keyring_name_lock)]    ||atomic_inc(&keyring->usage)
|  |.                                   ||| *** GET freeing keyring ***
|  |.                                   ||[read_unlock(&keyring_name_lock)]
|  ||                                   ||
|  |list_del()                          |[mutex_unlock(&key_user_k..mutex)]
|  ||                                   |
|  |[write_unlock(&keyring_name_lock)]  ** INVALID keyring is returned **
|  |                                    .
|  kmem_cache_free(,keyring)            .
|                                       .
|                                       atomic_dec(&keyring->usage)
v                                         *** DESTROYED ***
TIME

If CONFIG_SLUB_DEBUG=y then we may see the following message generated:

	=============================================================================
	BUG key_jar: Poison overwritten
	-----------------------------------------------------------------------------

	INFO: 0xffff880197a7e200-0xffff880197a7e200. First byte 0x6a instead of 0x6b
	INFO: Allocated in key_alloc+0x10b/0x35f age=25 cpu=1 pid=5086
	INFO: Freed in key_cleanup+0xd0/0xd5 age=12 cpu=1 pid=10
	INFO: Slab 0xffffea000592cb90 objects=16 used=2 fp=0xffff880197a7e200 flags=0x200000000000c3
	INFO: Object 0xffff880197a7e200 @offset=512 fp=0xffff880197a7e300

	Bytes b4 0xffff880197a7e1f0:  5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
	  Object 0xffff880197a7e200:  6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b jkkkkkkkkkkkkkkk

Alternatively, we may see a system panic happen, such as:

	BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
	IP: [<ffffffff810e61a3>] kmem_cache_alloc+0x5b/0xe9
	PGD 6b2b4067 PUD 6a80d067 PMD 0
	Oops: 0000 [#1] SMP
	last sysfs file: /sys/kernel/kexec_crash_loaded
	CPU 1
	...
	Pid: 31245, comm: su Not tainted 2.6.34-rc5-nofixed-nodebug #2 D2089/PRIMERGY
	RIP: 0010:[<ffffffff810e61a3>]  [<ffffffff810e61a3>] kmem_cache_alloc+0x5b/0xe9
	RSP: 0018:ffff88006af3bd98  EFLAGS: 00010002
	RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88007d19900b
	RDX: 0000000100000000 RSI: 00000000000080d0 RDI: ffffffff81828430
	RBP: ffffffff81828430 R08: ffff88000a293750 R09: 0000000000000000
	R10: 0000000000000001 R11: 0000000000100000 R12: 00000000000080d0
	R13: 00000000000080d0 R14: 0000000000000296 R15: ffffffff810f20ce
	FS:  00007f97116bc700(0000) GS:ffff88000a280000(0000) knlGS:0000000000000000
	CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
	CR2: 0000000000000001 CR3: 000000006a91c000 CR4: 00000000000006e0
	DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
	DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
	Process su (pid: 31245, threadinfo ffff88006af3a000, task ffff8800374414c0)
	Stack:
	 0000000512e0958e 0000000000008000 ffff880037f8d180 0000000000000001
	 0000000000000000 0000000000008001 ffff88007d199000 ffffffff810f20ce
	 0000000000008000 ffff88006af3be48 0000000000000024 ffffffff810face3
	Call Trace:
	 [<ffffffff810f20ce>] ? get_empty_filp+0x70/0x12f
	 [<ffffffff810face3>] ? do_filp_open+0x145/0x590
	 [<ffffffff810ce208>] ? tlb_finish_mmu+0x2a/0x33
	 [<ffffffff810ce43c>] ? unmap_region+0xd3/0xe2
	 [<ffffffff810e4393>] ? virt_to_head_page+0x9/0x2d
	 [<ffffffff81103916>] ? alloc_fd+0x69/0x10e
	 [<ffffffff810ef4ed>] ? do_sys_open+0x56/0xfc
	 [<ffffffff81008a02>] ? system_call_fastpath+0x16/0x1b
	Code: 0f 1f 44 00 00 49 89 c6 fa 66 0f 1f 44 00 00 65 4c 8b 04 25 60 e8 00 00 48 8b 45 00 49 01 c0 49 8b 18 48 85 db 74 0d 48 63 45 18 <48> 8b 04 03 49 89 00 eb 14 4c 89 f9 83 ca ff 44 89 e6 48 89 ef
	RIP  [<ffffffff810e61a3>] kmem_cache_alloc+0x5b/0xe9

This problem is that find_keyring_by_name does not confirm that the keyring is
valid before accepting it.

Skipping keyrings that have been reduced to a zero count seems the way to go.
To this end, use atomic_inc_not_zero() to increment the usage count and skip
the candidate keyring if that returns false.

The following script _may_ cause the bug to happen, but there's no guarantee
as the window of opportunity is small:

	#!/bin/sh
	LOOP=100000
	USER=dummy_user
	/bin/su -c "exit;" $USER || { /usr/sbin/adduser -m $USER; add=1; }
	for ((i=0; i<LOOP; i++))
	do
		/bin/su -c "echo '$i' > /dev/null" $USER
	done
	(( add == 1 )) && /usr/sbin/userdel -r $USER
	exit

Note that the nominated user must not be in use.

An alternative way of testing this may be:

	for ((i=0; i<100000; i++))
	do
		keyctl session foo /bin/true || break
	done >&/dev/null

as that uses a keyring named "foo" rather than relying on the user and
user-session named keyrings.
Reported-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

BugLink: https://launchpad.net/bugs/541802

The OR's hardware distorts at PCM 100% because it does not correspond to
0 dB. Fix this in patch_cxt5045() for all Packard Bell models.

Reported-by: Valombre
Cc: <stable@kernel.org>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Add a quirk for all-in-one computer Dell Inspiron One 19 Touch to have proper
HP and Mic support.
Signed-off-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

We should disable irqs when we take the tu->qlock because it is used in
the irq handler.  The only place that doesn't is
snd_timer_user_ccallback().  Most of the time snd_timer_user_ccallback()
is called with interrupts disabled but the the first ti->ccallback()
call in snd_timer_notify1() has interrupts enabled.

This was caught by lockdep which generates the following message:

> =================================
> [ INFO: inconsistent lock state ]
> 2.6.34-rc5 #5
> ---------------------------------
> inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
> dolphin/4003 [HC1[1]:SC0[0]:HE0:SE1] takes:
> (&(&tu->qlock)->rlock){?.+...}, at: [<f84ec472>] snd_timer_user_tinterrupt+0x28/0x132 [snd_timer]
> {HARDIRQ-ON-W} state was registered at:
>   [<c1048de9>] __lock_acquire+0x654/0x1482
>   [<c1049c73>] lock_acquire+0x5c/0x73
>   [<c125ac3e>] _raw_spin_lock+0x25/0x34
>   [<f84ec370>] snd_timer_user_ccallback+0x55/0x95 [snd_timer]
>   [<f84ecc4b>] snd_timer_notify1+0x53/0xca [snd_timer]
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Fix memory corruption that sometimes result in kernel panic.
Signed-off-by: Mattias Walström <mattias@vmlinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

BugLink: https://launchpad.net/bugs/549267

The OR verified that using the olpc-xo-1_5 model quirk allows the
headphones to be audible when inserted into the jack. Capture was
also verified to work correctly.

Reported-by: Richard Gagne
Tested-by: Richard Gagne
Cc: <stable@kernel.org>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

BugLink: https://launchpad.net/bugs/573284

The OR verified that using the olpc-xo-1_5 model quirk allows the
headphones to be audible when inserted into the jack. Capture was
also verified to work correctly.
Reported-by: Andy Couldrake <acouldrake@googlemail.com>
Tested-by: Andy Couldrake <acouldrake@googlemail.com>
Cc: <stable@kernel.org>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This fixes a problem where cards show up as only having a single mixer
element, suppressing all sound output.
Signed-off-by: Brian J. Tarricone <brian@tarricone.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/radeon/kms/legacy: only enable load detection property on DVI-I
  drm/radeon/kms: fix panel scaling adjusted mode setup
  drivers/gpu/drm/drm_sysfs.c: sysfs files error handling
  drivers/gpu/drm/radeon/radeon_atombios.c: range check issues
  gpu: vga_switcheroo, fix lock imbalance
  drivers/gpu/drm/drm_memory.c: fix check for end of loop
  drivers/gpu/drm/via/via_video.c: fix off by one issue
  drm/radeon/kms/agp The wrong AGP chipset can cause a NULL pointer dereference
  drm/radeon/kms: r300 fix CS checker to allow zbuffer-only fastfill

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

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
  powernow-k8: Fix frequency reporting
  x86: Fix parse_reservetop() build failure on certain configs
  x86: Fix NULL pointer access in irq_force_complete_move() for Xen guests
  x86: Fix 'reservetop=' functionality

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  KEYS: Fix RCU handling in key_gc_keyring()
  KEYS: Fix an RCU warning in the reading of user keys

key_gc_keyring() needs to either hold the RCU read lock or hold the keyring
semaphore if it's going to scan the keyring's list.  Given that it only needs
to read the key list, and it's doing so under a spinlock, the RCU read lock is
the thing to use.

Furthermore, the RCU check added in e7b0a61b is
incorrect as holding the spinlock on key_serial_lock is not grounds for
assuming a keyring's pointer list can be read safely.  Instead, a simple
rcu_dereference() inside of the previously mentioned RCU read lock is what we
want.
Reported-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

Fix an RCU warning in the reading of user keys:

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
security/keys/user_defined.c:202 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
1 lock held by keyctl/3637:
 #0:  (&key->sem){+++++.}, at: [<ffffffff811a80ae>] keyctl_read_key+0x9c/0xcf

stack backtrace:
Pid: 3637, comm: keyctl Not tainted 2.6.34-rc5-cachefs #18
Call Trace:
 [<ffffffff81051f6c>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffff811aa55f>] user_read+0x47/0x91
 [<ffffffff811a80be>] keyctl_read_key+0xac/0xcf
 [<ffffffff811a8a06>] sys_keyctl+0x75/0xb7
 [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

DVI-D doesn't have analog.  This matches the avivo behavior.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>