Add resources, platform device and convenience registration function for DA850's second MMC/SD controller (MMCSD1).
Signed-off-by: Juha Kuikka <juha.kuikka@elektrobit.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Split mmcsd_clk into mmcsd0_clk and mmcsd1_clk and add davinci_mmc.1
in preparation for adding support for MMCSD1 peripheral in DA850.
Signed-off-by: Juha Kuikka <juha.kuikka@elektrobit.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Add LPSC id for DA850's MMCSD1 peripheral.
Signed-off-by: Juha Kuikka <juha.kuikka@elektrobit.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

If irq2ctlr() fails return IRQ_NONE.
Also as it can fail make 'ctlr' signed.

The semantic patch that finds this problem (many false-positive results):
(http://coccinelle.lip6.fr/)

// <smpl>
@ r1 @
identifier f;
@@
int f(...) { ... }

@@
identifier r1.f;
type T;
unsigned T x;
@@

*x = f(...)
 ...
*x > 0
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

The CPGMAC pin list in da850.c was incorrectly split into two MII/RMII mode
specific pin lists, while what pin group is used is a function of how the board
is wired.  Copy the pin lists to board-da850-evm.c, renaming them accordingly,
and merge the two lists in da850.c into one, da850_cpgmac_pins[], representing
the CPGMAC module as a whole...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

The NAND/NOR flash pin lists (da850_nand_pins/da850_nor_pins) are purely board
specific and as such shouldn't be in da850.c -- copy them to board-da850-evm.c,
renaming to da850_evm_nand_pins/da850_evm_nor_pins respectively, and merge the
two lists in da850.c into one, representing the EMIF 2.5 module as a whole,
just like we have it in da830.c...

While at it, remove the '__init' modifier from da850_evm_setup_nor_nand() as
this function is called from non '__init' code...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

This is a bugfix for the original tnetv107x submission series.  The psc_regs
base array was being discarded post-init, and this was causing a crash during
post-init clock enable/disable.
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Keep PLL0 SYSCLK3 at a constant rate of 100MHz. This enables the AEMIF
timing to remain valid even as the PLL0 output is changed by cpufreq
driver to save power.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

On OMAP-L138 SoC, some of the sysclks need not be at a fixed ratio
to CPU clock and can be kept at a relatively constant rate by
adjusting the PLLDIVn ratio even as cpufreq goes ahead and changes
the CPU clock.

This feature can be used to keep the EMIFA (PLL0 SYSCLK3) clock at a
constant rate so that the EMIF timings need not be re-programmed
whenever the CPU frequency changes.

This patch adds the required suppport to cpufreq driver.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Setting sysclk rate will be useful in cases where the
sysclk is not at a fixed ratio to the PLL output but
can asynchronously be changed.

This support forms the basis of attempt to keep the AEMIF
clock constant on OMAP-L138 even as PLL0 output changes
as ARM clock is changed to save power.

This patch has been tested on OMAP-L138.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

This patch disables internal pulldowns for all MMC/SD1
pins. Presently only MMCSD1_CMD pin's pull down is
disabled, but with this some MMC/SD cards do not get
detected on MMC/SD1 slot of the EVM.

The problem was reproducible with SanDisk 4GB SDHC card.
Reported-by: Stephane Bovagne <s-bovagne@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

For each DA850 OPP, the normal ('NOM') voltage defined in the tecnical
reference manual (TRM) is actually the minimum voltage the frequency
is supported at.

The minimum ('MIN') voltage defined in TRM is meant to take care of
voltage fluctuations and the device should not be run at this voltage
for extended periods of time.

Fix the OPP definitions to define the cvdd_min as the normal voltage
defined in the datasheet.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

The Sitara AM17x SoCs from TI are an OMAP-L137 pin-to-pin
compatible ARM9 microprocessor offering from TI.

The Sitara AM18x SoCs from TI are an OMAP-L138 pin-to-pin
compatible ARM9 microprocessor offering from TI.

More information about these processors available at:
www.ti.com/am1x

Because of their compatibiliy with OMAP-L1x, the kernel
support for OMAP-L1x is fully relevant to AM1x processors.

This patch updates the Kconfig prompt and help text to include
the AM1x part names to help users select configurations required
for these parts easily.

Also, the hardware information that shows up in /proc/cpuinfo
is updated to show applicability of the respective OMAP-L1x EVMs
for AM1x parts.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

In arch/arm/mach-davinci/Kconfig, some of the configuration
items are indented with multiple spaces instead of tabs.

Also, in couple of places, two spaces are used in the middle
of help text where one should do.

This patch fixes both issues.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Current cpufreq code does not consider errors that can occur while
changing voltage. Code to increase CPU  frequency goes ahead even in
the case the regulator has failed to increase the voltage. This leads
to hard error since lower voltages cannot support increased frequency.

Prevent this by not increasing frequency in case increasing voltage
is not successful.

Also, do not lower the voltage if changing the cpu frequency has failed
for some reason.

Note that we do not return error on failure to decrease voltage as
that is not a hard error.

Build fix for non-cpufreq kernels by Caglar Akyuz.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cc: Caglar Akyuz <caglar@bilkon-kontrol.com.tr>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

The long list of clocks being disabled on boot is noisy and not needed
for standard boots.   Make this a debug printk instead.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

In absence of Kevin's e-mail address, using get_maintaner.pl in
git-send-email --cc-cmd option is not CCing Kevin at all.

While at it, mark davinci-linux-open-source@linux.davincidsp.com as
a list in line with what is being done for other maintainer entries.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Without this cleanup, sparse checker reports warnings of the type:

  CHECK   arch/arm/mach-davinci/board-da850-evm.c
arch/arm/mach-davinci/board-da850-evm.c:112:22: warning: symbol 'da850_evm_nandflash_partition' was not declared. Should it be static?

The nand flash partitions and regulator supplies are used within
the EVM file and so should have been static

This patch has been boot tested on DA830 and DA850 EVMs.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  Staging: vt6655: fix buffer overflow
  Revert: "Staging: batman-adv: Adding netfilter-bridge hooks"

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: musb: MAINTAINERS: Fix my mail address
  USB: serial/mos*: prevent reading uninitialized stack memory
  USB: otg: twl4030: fix phy initialization(v1)
  USB: EHCI: Disable langwell/penwell LPM capability
  usb: musb_debugfs: don't use the struct file private_data field with seq_files

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  serial: mfd: fix bug in serial_hsu_remove()
  serial: amba-pl010: fix set_ldisc

"param->u.wpa_associate.wpa_ie_len" comes from the user.  We should
check it so that the copy_from_user() doesn't overflow the buffer.

Also further down in the function, we assume that if
"param->u.wpa_associate.wpa_ie_len" is set then "abyWPAIE[0]" is
initialized.  To make that work, I changed the test here to say that if
"wpa_ie_len" is set then "wpa_ie" has to be a valid pointer or we return
-EINVAL.

Oddly, we only use the first element of the abyWPAIE[] array.  So I
suspect there may be some other issues in this function.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This reverts commit 96d592ed.

The netfilter hook seems to be misused and may leak skbs in situations
when NF_HOOK returns NF_STOLEN. It may not filter everything as
expected. Also the ethernet bridge tables are not yet capable to
understand batman-adv packet correctly.

It was only added for testing purposes and can be removed again.
Reported-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Medfield HSU driver deal with 4 pci devices(3 uart ports + 1 dma controller),
so in pci remove func, we need handle them differently
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Commit d87d9b7d ("tty: serial - fix tty referencing in set_ldisc") changed
set_ldisc to take ldisc number as parameter. This patch fixes AMBA PL010 driver
according the new prototype.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

If we don't, contributors to musb and any USB OMAP
code will be sending mails to an unexistent inbox.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The TIOCGICOUNT device ioctl in both mos7720.c and mos7840.c allows
unprivileged users to read uninitialized stack memory, because the
"reserved" member of the serial_icounter_struct struct declared on the
stack is not altered or zeroed before being copied back to the user.
This patch takes care of it.
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Commit 461c3177(into 2.6.36-v3)
is put forward to power down phy if no usb cable is connected,
but does introduce the two issues below:

1), phy is not into work state if usb cable is connected
with PC during poweron, so musb device mode is not usable
in such case, follows the reasons:
	-twl4030_phy_resume is not called, so
		regulators are not enabled
		i2c access are not enabled
		usb mode not configurated

2), The kernel warings[1] of regulators 'unbalanced disables'
is caused if poweron without usb cable connected
with PC or b-device.

This patch fixes the two issues above:
	-power down phy only if no usb cable is connected with PC
and b-device
	-do phy initialization(via __twl4030_phy_resume) if usb cable
is connected with PC(vbus event) or another b-device(ID event) in
twl4030_usb_probe.

This patch also doesn't put VUSB3V1 LDO into active mode in
twl4030_usb_ldo_init until VBUS/ID change detected, so we can
save more power consumption than before.

This patch is verified OK on Beagle board either connected with
usb cable or not when poweron.

[1]. warnings of 'unbalanced disables' of regulators.
[root@OMAP3EVM /]# dmesg
------------[ cut here ]------------
WARNING: at drivers/regulator/core.c:1357 _regulator_disable+0x38/0x128()
unbalanced disables for VUSB1V8
Modules linked in:
Backtrace:
[<c0030c48>] (dump_backtrace+0x0/0x110) from [<c034f5a8>] (dump_stack+0x18/0x1c)
 r7:c78179d8 r6:c01ed6b8 r5:c0410822 r4:0000054d
[<c034f590>] (dump_stack+0x0/0x1c) from [<c0057da8>] (warn_slowpath_common+0x54/0x6c)
[<c0057d54>] (warn_slowpath_common+0x0/0x6c) from [<c0057e64>] (warn_slowpath_fmt+0x38/0x40)
 r9:00000000 r8:00000000 r7:c78e6608 r6:00000000 r5:fffffffb
 r4:c78e6c00
[<c0057e2c>] (warn_slowpath_fmt+0x0/0x40) from [<c01ed6b8>] (_regulator_disable+0x38/0x128)
 r3:c0410e53 r2:c0410ad5
[<c01ed680>] (_regulator_disable+0x0/0x128) from [<c01ed87c>] (regulator_disable+0x24/0x38)
 r7:c78e6608 r6:00000000 r5:c78e6c40 r4:c78e6c00
[<c01ed858>] (regulator_disable+0x0/0x38) from [<c02382dc>] (twl4030_phy_power+0x15c/0x17c)
 r5:c78595c0 r4:00000000
[<c0238180>] (twl4030_phy_power+0x0/0x17c) from [<c023831c>] (twl4030_phy_suspend+0x20/0x2c)
 r6:00000000 r5:c78595c0 r4:c78595c0
[<c02382fc>] (twl4030_phy_suspend+0x0/0x2c) from [<c0238638>] (twl4030_usb_irq+0x11c/0x16c)
 r5:c78595c0 r4:00000040
[<c023851c>] (twl4030_usb_irq+0x0/0x16c) from [<c034ec18>] (twl4030_usb_probe+0x2c4/0x32c)
 r6:00000000 r5:00000000 r4:c78595c0
[<c034e954>] (twl4030_usb_probe+0x0/0x32c) from [<c02152a0>] (platform_drv_probe+0x20/0x24)
 r7:00000000 r6:c047d49c r5:c78e6608 r4:c047d49c
[<c0215280>] (platform_drv_probe+0x0/0x24) from [<c0214244>] (driver_probe_device+0xd0/0x190)
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c02143d4>] (__device_attach+0x44/0x48)
 r7:00000000 r6:c78e6608 r5:c78e6608 r4:c047d49c
[<c0214390>] (__device_attach+0x0/0x48) from [<c0213694>] (bus_for_each_drv+0x50/0x90)
 r5:c0214390 r4:00000000
[<c0213644>] (bus_for_each_drv+0x0/0x90) from [<c0214474>] (device_attach+0x70/0x94)
 r6:c78e663c r5:c78e6608 r4:c78e6608
[<c0214404>] (device_attach+0x0/0x94) from [<c02134fc>] (bus_probe_device+0x2c/0x48)
 r7:00000000 r6:00000002 r5:c78e6608 r4:c78e6600
[<c02134d0>] (bus_probe_device+0x0/0x48) from [<c0211e48>] (device_add+0x340/0x4b4)
[<c0211b08>] (device_add+0x0/0x4b4) from [<c021597c>] (platform_device_add+0x110/0x16c)
[<c021586c>] (platform_device_add+0x0/0x16c) from [<c0220cb0>] (add_numbered_child+0xd8/0x118)
 r7:00000000 r6:c045f15c r5:c78e6600 r4:00000000
[<c0220bd8>] (add_numbered_child+0x0/0x118) from [<c001c618>] (twl_probe+0x3a4/0x72c)
[<c001c274>] (twl_probe+0x0/0x72c) from [<c02601ac>] (i2c_device_probe+0x7c/0xa4)
[<c0260130>] (i2c_device_probe+0x0/0xa4) from [<c0214244>] (driver_probe_device+0xd0/0x190)
 r5:c7856e20 r4:c047c860
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c02143d4>] (__device_attach+0x44/0x48)
 r7:c7856e04 r6:c7856e20 r5:c7856e20 r4:c047c860
[<c0214390>] (__device_attach+0x0/0x48) from [<c0213694>] (bus_for_each_drv+0x50/0x90)
 r5:c0214390 r4:00000000
[<c0213644>] (bus_for_each_drv+0x0/0x90) from [<c0214474>] (device_attach+0x70/0x94)
 r6:c7856e54 r5:c7856e20 r4:c7856e20
[<c0214404>] (device_attach+0x0/0x94) from [<c02134fc>] (bus_probe_device+0x2c/0x48)
 r7:c7856e04 r6:c78fd048 r5:c7856e20 r4:c7856e20
[<c02134d0>] (bus_probe_device+0x0/0x48) from [<c0211e48>] (device_add+0x340/0x4b4)
[<c0211b08>] (device_add+0x0/0x4b4) from [<c0211fd8>] (device_register+0x1c/0x20)
[<c0211fbc>] (device_register+0x0/0x20) from [<c0260aa8>] (i2c_new_device+0xec/0x150)
 r5:c7856e00 r4:c7856e20
[<c02609bc>] (i2c_new_device+0x0/0x150) from [<c0260dc0>] (i2c_register_adapter+0xa0/0x1c4)
 r7:00000000 r6:c78fd078 r5:c78fd048 r4:c781d5c0
[<c0260d20>] (i2c_register_adapter+0x0/0x1c4) from [<c0260f80>] (i2c_add_numbered_adapter+0x9c/0xb4)
 r7:00000a28 r6:c04600a8 r5:c78fd048 r4:00000000
[<c0260ee4>] (i2c_add_numbered_adapter+0x0/0xb4) from [<c034efa4>] (omap_i2c_probe+0x324/0x3e8)
 r5:00000000 r4:c78fd000
[<c034ec80>] (omap_i2c_probe+0x0/0x3e8) from [<c02152a0>] (platform_drv_probe+0x20/0x24)
[<c0215280>] (platform_drv_probe+0x0/0x24) from [<c0214244>] (driver_probe_device+0xd0/0x190)
[<c0214174>] (driver_probe_device+0x0/0x190) from [<c021436c>] (__driver_attach+0x68/0x8c)
 r7:c78b2140 r6:c047e214 r5:c04600e4 r4:c04600b0
[<c0214304>] (__driver_attach+0x0/0x8c) from [<c021399c>] (bus_for_each_dev+0x50/0x84)
 r7:c78b2140 r6:c047e214 r5:c0214304 r4:00000000
[<c021394c>] (bus_for_each_dev+0x0/0x84) from [<c0214068>] (driver_attach+0x20/0x28)
 r6:c047e214 r5:c047e214 r4:c00270d0
[<c0214048>] (driver_attach+0x0/0x28) from [<c0213274>] (bus_add_driver+0xa8/0x228)
[<c02131cc>] (bus_add_driver+0x0/0x228) from [<c02146a4>] (driver_register+0xb0/0x13c)
[<c02145f4>] (driver_register+0x0/0x13c) from [<c0215744>] (platform_driver_register+0x4c/0x60)
 r9:00000000 r8:c001f688 r7:00000013 r6:c005b6fc r5:c00083dc
r4:c00270d0
[<c02156f8>] (platform_driver_register+0x0/0x60) from [<c001f69c>] (omap_i2c_init_driver+0x14/0x1c)
[<c001f688>] (omap_i2c_init_driver+0x0/0x1c) from [<c002c460>] (do_one_initcall+0xd0/0x1a4)
[<c002c390>] (do_one_initcall+0x0/0x1a4) from [<c0008478>] (kernel_init+0x9c/0x154)
[<c00083dc>] (kernel_init+0x0/0x154) from [<c005b6fc>] (do_exit+0x0/0x688)
 r5:c00083dc r4:00000000
---[ end trace 1b75b31a2719ed1d ]---
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Felipe Balbi <me@felipebalbi.com>
Cc: Anand Gadiyar <gadiyar@ti.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

We have to do so due to HW limitation.
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

seq_files use the private_data field of a file struct for storing a seq_file structure,
data should be stored in seq_file's own private field (e.g. file->private_data->private)
Otherwise seq_release() will free the private data when the file is closed.
Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

We need to make sure that only the first do_signal() to be handled on
the way out syscall will bother with syscall restarts; additionally, the
check on the "signal has user handler" path had been wrong - compare
with restart prevention in sigreturn()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

do_signal() should place the syscall number in gr7, not gr8 when
handling ERESTART_WOULDBLOCK.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use force_sigsegv() rather than force_sig(SIGSEGV, ...) as the former
resets the SEGV handler pointer which will kill the process, rather than
leaving it open to an infinite loop if the SEGV handler itself caused a
SEGV signal.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

a) sa_handler might be maliciously set to point to kernel memory;
   blindly dereferencing it in FDPIC case is a Bad Idea(tm).

b) I'm not sure you need that set_fs(USER_DS) there at all, but if you
   do, you'd better do it *before* checking the frame you've decided to
   use with access_ok(), lest sigaltstack() becomes a convenient
   roothole.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Reset restart_block.fn on executing a sigreturn such that any currently
pending system call restarts will be forced to return -EINTR.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 4969c119 ("mm: fix swapin race condition") is now agreed to
be incomplete.  There's a race, not very much less likely than the
original race envisaged, in which it is further necessary to check that
the swapcache page's swap has not changed.

Here's the reasoning: cast in terms of reuse_swap_page(), but probably
could be reformulated to rely on try_to_free_swap() instead, or on
swapoff+swapon.

A, faults into do_swap_page(): does page1 = lookup_swap_cache(swap1) and
comes through the lock_page(page1).

B, a racing thread of the same process, faults on the same address: does
page1 = lookup_swap_cache(swap1) and now waits in lock_page(page1), but
for whatever reason is unlucky not to get the lock any time soon.

A carries on through do_swap_page(), a write fault, but cannot reuse the
swap page1 (another reference to swap1).  Unlocks the page1 (but B
doesn't get it yet), does COW in do_wp_page(), page2 now in that pte.

C, perhaps the parent of A+B, comes in and write faults the same swap
page1 into its mm, reuse_swap_page() succeeds this time, swap1 is freed.

kswapd comes in after some time (B still unlucky) and swaps out some
pages from A+B and C: it allocates the original swap1 to page2 in A+B,
and some other swap2 to the original page1 now in C.  But does not
immediately free page1 (actually it couldn't: B holds a reference),
leaving it in swap cache for now.

B at last gets the lock on page1, hooray! Is PageSwapCache(page1)? Yes.
Is pte_same(*page_table, orig_pte)? Yes, because page2 has now been
given the swap1 which page1 used to have.  So B proceeds to insert page1
into A+B's page_table, though its content now belongs to C, quite
different from what A wrote there.

B ought to have checked that page1's swap was still swap1.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha-2.6:
  alpha: deal with multiple simultaneously pending signals
  alpha: fix a 14 years old bug in sigreturn tracing
  alpha: unb0rk sigsuspend() and rt_sigsuspend()
  alpha: belated ERESTART_RESTARTBLOCK race fix
  alpha: Shift perf event pending work earlier in timer interrupt
  alpha: wire up fanotify and prlimit64 syscalls
  alpha: kill big kernel lock
  alpha: fix build breakage in asm/cacheflush.h
  alpha: remove unnecessary cast from void* in assignment.
  alpha: Use static const char * const where possible

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  ide: Fix ordering of procfs registry.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  dca: disable dca on IOAT ver.3.0 multiple-IOH platforms
  netpoll: Disable IRQ around RCU dereference in netpoll_rx
  sctp: Do not reset the packet during sctp_packet_config().
  net/llc: storing negative error codes in unsigned short
  MAINTAINERS: move atlx discussions to netdev
  drivers/net/cxgb3/cxgb3_main.c: prevent reading uninitialized stack memory
  drivers/net/eql.c: prevent reading uninitialized stack memory
  drivers/net/usb/hso.c: prevent reading uninitialized memory
  xfrm: dont assume rcu_read_lock in xfrm_output_one()
  r8169: Handle rxfifo errors on 8168 chips
  3c59x: Remove atomic context inside vortex_{set|get}_wol
  tcp: Prevent overzealous packetization by SWS logic.
  net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS
  phylib: fix PAL state machine restart on resume
  net: use rcu_barrier() in rollback_registered_many
  bonding: correctly process non-linear skbs
  ipv4: enable getsockopt() for IP_NODEFRAG
  ipv4: force_igmp_version ignored when a IGMPv3 query received
  ppp: potential NULL dereference in ppp_mp_explode()
  net/llc: make opt unsigned in llc_ui_setsockopt()
  ...