Set the hardware to ignore all write/erase cycles to the GbE region in
the ICHx NVM.  This feature can be disabled by the WriteProtectNVM module
parameter (enabled by default) only after a hardware reset, but
the machine must be power cycled before trying to enable writes.
Signed-off-by: NBruce Allan <bruce.w.allan@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
CC: arjan@linux.intel.com
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes a build error in the pxa2xx-spi driver,
introduced by commit 7e964455
("pxa2xx_spi: dma bugfixes")

  CC      drivers/spi/pxa2xx_spi.o
drivers/spi/pxa2xx_spi.c: In function 'map_dma_buffers':
drivers/spi/pxa2xx_spi.c:331: error: invalid operands to binary &
drivers/spi/pxa2xx_spi.c:331: error: invalid operands to binary &
drivers/spi/pxa2xx_spi.c: In function 'pump_transfers':
drivers/spi/pxa2xx_spi.c:897: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'unsigned int'

[dbrownell@users.sourceforge.net: fix warning too ]
Signed-off-by: NMike Rapoport <mike@compulab.co.il>
Acked-by: NEric Miao <eric.miao@marvell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NLinus 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, vmi: fix broken LDT access
  x86: fix typo in enable_mtrr_cleanup early parameter

Fix the IRQ handling on the MN10300 arch.

This patch makes a number of significant changes:

 (1) It separates the irq_chip definition for edge-triggered interrupts from
     the one for level-triggered interrupts.

     This is necessary because the MN10300 PIC latches the IRQ channel's
     interrupt request bit (GxICR_REQUEST), even after the device has ceased to
     assert its interrupt line and the interrupt channel has been disabled in
     the PIC.  So for level-triggered interrupts we need to clear this bit when
     we re-enable - which is achieved by setting GxICR_DETECT but not
     GxICR_REQUEST when writing to the register.

     Not doing this results in spurious interrupts occurring because calling
     mask_ack() at the start of handle_level_irq() is insufficient - it fails
     to clear the REQUEST latch because the device that caused the interrupt is
     still asserting its interrupt line at this point.

 (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt
     request flag for edge-triggered interrupts lest it lose an interrupt.

 (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt
     request flag for edge-triggered interrupts lest it lose an interrupt.

 (4) The end() operation is now left to the default (no-operation) as
     __do_IRQ() is compiled out.  This may affect misrouted_irq(), but
     according to Thomas Gleixner it's the correct thing to do.

 (5) handle_level_irq() is used for edge-triggered interrupts rather than
     handle_edge_irq() as the MN10300 PIC latches interrupt events even on
     masked IRQ channels, thus rendering IRQ_PENDING unnecessary.  It is
     sufficient to call mask_ack() at the start and unmask() at the end.

 (6) For level-triggered interrupts, ack() is now NULL as it's not used, and
     there is no effective ACK function on the PIC.  mask_ack() is now the
     same as mask() as the latch continues to latch, even when the channel is
     masked.

Further, the patch discards the disable() op implementation as its now the same
as the mask() op implementation, which is used instead.

It also discards the enable() op implementations as they're now the same as
the unmask() op implementations, which are used instead.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm mpath: add missing path switching locking
  dm: cope with access beyond end of device in dm_merge_bvec
  dm: always allow one page in dm_merge_bvec

* 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

Moving the path activation to workqueue along with scsi_dh patches introduced
a race. It is due to the fact that the current_pgpath (in the multipath data
structure) can be modified if changes happen in any of the paths leading to
the lun. If the changes lead to current_pgpath being set to NULL, then it
leads to the invalid access which results in the panic below.

This patch fixes that by storing the pgpath to activate in the multipath data
structure and properly protecting it.

Note that if activate_path is called twice in succession with different pgpath,
with the second one being called before the first one is done, then activate
path will be called twice for the second pgpath, which is fine.

Unable to handle kernel paging request for data at address 0x00000020
Faulting instruction address: 0xd000000000aa1844
cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80]
    pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath]
    lr: c000000000087a2c: .run_workqueue+0x114/0x204
    sp: c00000006b987d00
   msr: 8000000000009032
   dar: 20
 dsisr: 40000000
  current = 0xc0000000676bb3f0
  paca    = 0xc0000000006f3680
    pid   = 2528, comm = kmpath_handlerd
enter ? for help
[c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204
[c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144
[c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4
[c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

If for any reason dm_merge_bvec() is given an offset beyond the end of the
device, avoid an oops and always allow one page to be added to an empty bio.
We'll reject the I/O later after the bio is submitted.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Some callers assume they can always add at least one page to an empty bio,
so dm_merge_bvec should not return 0 in this case: we'll reject the I/O
later after the bio is submitted.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

Fix a xfrm_{state,policy}_walk leak if pfkey socket is closed while
dumping is on-going.
Signed-off-by: NTimo Teras <timo.teras@iki.fi>
Signed-off-by: NDavid 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: NArnaud Ebalard <arno@natisbad.org>
Acked-by: NBenjamin Thery <benjamin.thery@bull.net>
Signed-off-by: NDavid 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: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid 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: NVitaliy Gusev <vgusev@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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 75b8bb3e

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.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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: NZachary 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: NLinus 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: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: NPaul 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: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid 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: NTakashi 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: NJean Delvare <khali@linux-fr.org>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NTakashi 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: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NDavid 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: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Correct typo for 'enable_mtrr_cleanup' early boot param name.
Signed-off-by: NJ.A. Magallon <jamagallon@ono.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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

HAVE_GPIO_LIB has basically been replaced by GPIOLIB
Signed-off-by: NSamuel 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: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NJoel Schopp <jschopp@austin.ibm.com>
Signed-off-by: NBenjamin 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: NDavid Gibson <david@gibson.dropbear.id.au>
Acked-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin 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: NTony 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: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus 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: NThomas 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: NThomas Gleixner <tglx@linutronix.de>