namespaces Kconfig: remove pointless cgroup dependency

The different cgroup subsystems are under the cgroup submenu.  The
dependency between the cgroups and the menu subsystems is pointless.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.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>

namespaces Kconfig: make namespace a submenu

Make the namespaces config option a submenu.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.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>

namespaces: default all the namespaces to 'yes' when CONFIG_NAMESPACES is selected

As the different namespaces depend on 'CONFIG_NAMESPACES', it is logical
to enable all the namespaces when we enable NAMESPACES.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Miller <davem@davemloft.net>
Acked-By: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

namespaces: remove pid_ns and net_ns experimental status

The pid namespace is in the kernel since 2.6.27 and the net_ns since
2.6.29.  They are enabled in the distro by default and used by userspace
component.  They are mature enough to remove the 'experimental' label.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: fix destructive port EM initialization for Tsi568

Replace possibly damaging broadcast writes into the per-port SP_MODE
registers with individual writes for each port.  This will preserve
individual port configurations in case if ports are configured
differently.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: fix maximum port number in tsi57x EM initialization

Replace hardcoded maximum port number with actual reported number of
switch ports.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: fix IDLE2 bits corruption

RapidIO spec v.2.1 adds Idle Sequence 2 into LP-Serial Physical Layer.
The fix ensures that corresponding bits are not corrupted during error
handling.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add handling of redundant routes

Detects RIO link to the already enumerated device and properly sets links
between device objects.  Changes to the enumeration/discovery logic:

1. Use Master Enable bit to signal end of the enumeration - agents may
   start their discovery process as soon as they see this bit set
   (Component Tag register was used before for this purpose).

2. Enumerator sets Component Tag (!= 0) immediately during device
   setup.  This allows to identify the device if the redundant route
   exists in a RIO system.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add support for IDT CPS Gen2 switches

Add the RIO switch driver and definitions for IDT CPS-1848 and CPS-1616
Gen2 devices.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add device access check into the enumeration

Add explicit device access check before performing device enumeration.
This gives a chance to clear possible link error conditions by issuing
safe maintenance read request(s).

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add handling of orphan port-write message

Add check for access to port-write (PW) message source device before
processing the PW message.  If source RIO device is not available (power
down or RIO link failure) trace back to a last available switch/port on
the PW message route and service failure at that point.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: modify sysfs initialization for switches

1. Change to create attribute "routes" only for switches.

2. Add a switch-specific callback to create/remove proprietary attributes.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add default handler for error-stopped state

The default error-stopped state handler provides recovery mechanism as
defined by RIO specification.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: add relation links between RIO device structures

Create back and forward links between RIO devices.  These links are
intended for use by error management and hot-plug extensions.  Links for
redundant RIO connections between switches are not set (will be fixed in a
separate patch).

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: use stored ingress port number instead of register read

The switch port information is obtained and stored during RIO device
setup.  Therefore repeated reads from Switch Port Information CAR may be
removed.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio:powerpc/85xx: modify RIO port-write interrupt handler

- Rearrange RIO port-write interrupt handling to perform message
  buffering as soon as possible.

- Modify to disable port-write controller when clearing Transaction
  Error (TE) bit.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: fix RapidIO sysfs hierarchy

This set of RapidIO patches extends support for standard error recovery
mechanism and adds new IDT Gen2 sRIO switch devices - CPS-1848 and
CPS-1616.  Implementation of the standard error-stopped state recovery
mechanism (as defined by the RapidIO specification) is required for the
new switches.

Version 2 of this set of patches addresses received comments and fixes an
error notification setup issue found in the idt_gen2.c after the first
version was released.

This patch:

Make RapidIO devices appear in /sys/devices/rapidio directory instead of
top of /sys/devices directory.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/mxser.c: fix compilation warning in mxser.c

Both mxser_disable_must_enchance_mode() and mxser_get_must_hardware_id()
called from function CheckIsMoxaMust(), when CONFIG_PCI=y.  So mark both
the functions under CONFIG_PCI.

We were warned by the following warning.

drivers/char/mxser.c:306: warning: `mxser_disable_must_enchance_mode' defined but not used
drivers/char/mxser.c:391: warning: `mxser_get_must_hardware_id'
defined but not used

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/rio/Makefile: replace the use of <module>-objs with <module>-y

Changed <module>-objs to <module>-y in Makefile.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/pcmcia/ipwireless/Makefile: Makefile: replace the use of <module>-objs with <module>-y

Changed <module>-objs to <module>-y in Makefile.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/mwave/Makefile: clean up

Changed <module>-objs to <module>-y in Makefile and use
ccflags-y option.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/ipmi/Makefile: replace the use of <module>-objs with <module>-y

Changed <module>-objs to <module>-y in Makefile.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/ip2/Makefile: replace the use of <module>-objs with <module>-y

Changed <module>-objs to <module>-y in Makefile.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/synclink_gt.c: add extended sync feature

Add support for extended byte synchronous mode feature of hardware.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/synclink_gt.c: fix information leak to userland

Structures tmp_params and new_line are copied to userland with some
padding fields unitialized.  It leads to leaking of stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Acked-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/ppdev.c: fix information leak to userland

Structure par_timeout is copied to userland with some padding fields
unitialized.  Field tv_usec has type __kernel_suseconds_t, it differs from
tv_sec's type on some architectures.  It leads to leaking of stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/applicom.c: fix information leak to userland

Structure st_loc is copied to userland with some fields unitialized.  It
leads to leaking of stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

synclink_gt: fix per device locking

Fix a long standing bug with per device locking.

Each device has an associated spinlock for synchronizing access to
hardware and state information with the ISR.  A single hardware card has
one or more devices.

Bug: Non ISR code correctly acquires and releases the per device lock.
ISR incorrectly always acquires and releases the lock of the first device
on the card.

The decoupled and list based nature of the ISR and deferred processing
interaction allowed this to work in normal operation.  Exceptional events
like an application forcing hardware shutdown, reset, or reconfiguration
while active can trigger the bug.

Fixed ISR to acquire and release the per device lock.

One exception is manipulation of the GPIO card resource which is global
and effectively owned by the first device of the card.  Non-ISR access to
GPIO resource is changed to use lock of first device on card.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SGI Altix IA64 mmtimer: eliminate long interval timer holdoffs

This patch for SGI Altix/IA64 eliminates interval long timer holdoffs in
cases where we don't start an interval timer before the expiration time.
This sometimes happens when a number of interval timers on the same shub
with the same interval run simultaneously.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/hvc_console.c: remove unneeded __set_current_state(TASK_RUNNING)

This doesn't do anything.

Cc: Timur Tabi <timur@freescale.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/rocket.c: release_region or error path

There was a release_region() missing on the error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipmi: fix __init and __exit attribute locations

__init and __exit belong after the return type on functions, not
before.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc: initialize structure memory to zero for compat functions

This takes care of leaking uninitialized kernel stack memory to
userspace from non-zeroed fields in structs in compat ipc functions.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/shm.c: add RSS and swap size information to /proc/sysvipc/shm

The kernel currently provides no functionality to analyze the RSS and swap
space usage of each individual sysvipc shared memory segment.

This patch adds this info for each existing shm segment by extending the
output of /proc/sysvipc/shm by two columns for RSS and swap.

Since shmctl(SHM_INFO) already provides a similiar calculation (it
currently sums up all RSS/swap info for all segments), I did split out a
static function which is now used by the /proc/sysvipc/shm output and
shmctl(SHM_INFO).

SAP products (esp.  the SAP Netweaver ABAP Kernel) uses lots of big shared
memory segments (we often have Linux systems with >= 16GB shm usage).
Sometimes we get customer reports about "slow" system responses and while
looking into their configurations we often find massive swapping activity
on the system.  With this patch it's now easy to see from the command line
if and which shm segments gets swapped out (and how much) and can more
easily give recommendations for system tuning.  Without the patch it's
currently not possible to do such shm analysis at all.

Also...

Add some spaces in front of the "size" field for 64bit kernels to get the
columns correct if you cat the contents of the file.  In
sysvipc_shm_proc_show() the kernel prints the size value in "SPEC_SIZE"
format, which is defined like this:

#if BITS_PER_LONG <= 32
#define SIZE_SPEC "%10lu"
#else
#define SIZE_SPEC "%21lu"
#endif

So, if the header is not adjusted, the columns are not correctly aligned.
I actually tested this on 32- and 64-bit and it seems correct now.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exec: don't turn PF_KTHREAD off when a target command was not found

Presently do_execve() turns PF_KTHREAD off before search_binary_handler().
 THis has a theorical risk of PF_KTHREAD getting lost.  We don't have to
turn PF_KTHREAD off in the ENOEXEC case.

This patch moves this flag modification to after the finding of the
executable file.

This is only a theorical issue because kthreads do not call do_execve()
directly.  But fixing would be better.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/proc/stat: fix scalability of irq sum of all cpu

In /proc/stat, the number of per-IRQ event is shown by making a sum each
irq's events on all cpus.  But we can make use of kstat_irqs().

kstat_irqs() do the same calculation, If !CONFIG_GENERIC_HARDIRQ,
it's not a big cost. (Both of the number of cpus and irqs are small.)

If a system is very big and CONFIG_GENERIC_HARDIRQ, it does

for_each_irq()
for_each_cpu()
- look up a radix tree
- read desc->irq_stat[cpu]
This seems not efficient. This patch adds kstat_irqs() for
CONFIG_GENRIC_HARDIRQ and change the calculation as

for_each_irq()
look up radix tree
for_each_cpu()
- read desc->irq_stat[cpu]

This reduces cost.

A test on (4096cpusp, 256 nodes, 4592 irqs) host (by Jack Steiner)

%time cat /proc/stat > /dev/null

Before Patch:  2.459 sec
After Patch :   .561 sec

[akpm@linux-foundation.org: unexport kstat_irqs, coding-style tweaks]
[akpm@linux-foundation.org: fix unused variable 'per_irq_sum']
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/proc/stat: scalability of irq num per cpu

/proc/stat shows the total number of all interrupts to each cpu.  But when
the number of IRQs are very large, it take very long time and 'cat
/proc/stat' takes more than 10 secs.  This is because sum of all irq
events are counted when /proc/stat is read.  This patch adds "sum of all
irq" counter percpu and reduce read costs.

The cost of reading /proc/stat is important because it's used by major
applications as 'top', 'ps', 'w', etc....

A test on a mechin (4096cpu, 256 nodes, 4592 irqs) shows

 %time cat /proc/stat > /dev/null
 Before Patch:  12.627 sec
 After  Patch:  2.459 sec

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

procfs: fix /proc/softirqs formatting

The length of the BLOCK_IPOLL string is making i's value be printed too
far to the right.  This patch fixes this and makes the output a bit
neater.

Currently:
                CPU0
      HI:          0
   TIMER:     599792
  NET_TX:          2
  NET_RX:          6
   BLOCK:      80807
BLOCK_IOPOLL:          0
 TASKLET:      20012
   SCHED:          0
 HRTIMER:         63
     RCU:     619279

With patch:
                    CPU0
          HI:          0
       TIMER:     585582
      NET_TX:          2
      NET_RX:          6
       BLOCK:      80320
BLOCK_IOPOLL:          0
     TASKLET:      19287
       SCHED:          0
     HRTIMER:         62
         RCU:     604441

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Acked-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/proc/pid/pagemap: document in Documentation/filesystems/proc.txt

Document /proc/pid/pagemap in Documentation/filesystems/proc.txt

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: Richard Guenther <rguenther@suse.de>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/proc/pid/smaps: export amount of anonymous memory in a mapping

Export the number of anonymous pages in a mapping via smaps.

Even the private pages in a mapping backed by a file, would be marked as
anonymous, when they are modified. Export this information to user-space via
smaps.

Exporting this count will help gdb to make a better decision on which
areas need to be dumped in its coredump; and should be useful to others
studying the memory usage of a process.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exit: add lock context annotation on find_new_reaper()

find_new_reaper() releases and regrabs tasklist_lock but was missing
proper annotations.  Add it.  This remove following sparse warning:

 warning: context imbalance in 'find_new_reaper' - unexpected unlock

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

coredump: default CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS=y

The userland ELF tools have been coping with partial-segments core files
for a few years now.  Multiple distro builds are now setting this option.
It behooves everyone who ever deals with core files to have more info
dumped in there, especially as more and more people's compilers are
producing build IDs.  Make it the default.

Anyone using older tools confused by these core files can configure this
option off, or just change /proc/PID/coredump_filter after boot.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

core_pattern: fix truncation by core_pattern handler with long parameters

We met a parameter truncated issue, consider following:
> echo "|/root/core_pattern_pipe_test %p /usr/libexec/blah-blah-blah \
%s %c %p %u %g 11 12345678901234567890123456789012345678 %t" > \
/proc/sys/kernel/core_pattern

This is okay because the strings is less than CORENAME_MAX_SIZE.  "cat
/proc/sys/kernel/core_pattern" shows the whole string.  but after we run
core_pattern_pipe_test in man page, we found last parameter was truncated
like below:

        argc[10]=<12807486>

The root cause is core_pattern allows % specifiers, which need to be
replaced during parse time, but the replace may expand the strings to
larger than CORENAME_MAX_SIZE.  So if the last parameter is % specifiers,
the replace code is using snprintf(out_ptr, out_end - out_ptr, ...), this
will write out of corename array.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

signals: move cred_guard_mutex from task_struct to signal_struct

Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec
itself and we can reuse ->cred_guard_mutex for it.  Yes, concurrent
execve() has no worth.

Let's move ->cred_guard_mutex from task_struct to signal_struct.  It
naturally prevent multiple-threads-inside-exec.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

signals: annotate lock context change on ptrace_stop()

ptrace_stop() releases and regrabs current->sighand->siglock but was
missing proper annotation.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

signals: annotate lock_task_sighand()

lock_task_sighand() grabs sighand->siglock in case of returning non-NULL
but unlock_task_sighand() releases it unconditionally.  This leads sparse
to complain about the lock context imbalance.  Rename and wrap
lock_task_sighand() using __cond_lock() macro to make sparse happy.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on xtensa

Use new 'datap' variable in order to remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on um

Remove unnecessary castings using void pointer and fix copy_to_user()
return value. Also add missing __user markup on the argument of
arch_ptrctl().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on tile

Remove checking @addr less than 0 because @addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on sparc

Factor out struct fps and remove redundant castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on sh

Remove unnecessary castings and get rid of dummy pointer in favor of
offsetof() macro in ptrace_32.c. Also use temporary variables and
break long lines in order to improve readability.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on score

Remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on powerpc

Use new 'datavp' and 'datalp' variables in order to remove unnecessary
castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on parisc

Add missing __user markup on the argument of put_user().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on mn10300

Use new 'datap' variable in order to remove unnecessary castings.
Also remove checking @addr less than 0 because @addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on MIPS

Use new 'addrp', 'datavp' and 'datalp' variables in order to remove
unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on microblaze

Remove checking @addr greater than 0 because @addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on m68knommu

Use new 'regno', 'datap' variables in order to remove duplicated
expressions and unnecessary castings.  Alse remove checking @addr less
than 0 because addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on m68k

Use new 'regno', 'datap' variables in order to remove duplicated
expressions and unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on m32r

Use new 'datap' variable in order to remove duplicated castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on h8300

Use new 'regno', 'datap' variables in order to remove duplicated
expressions and unnecessary castings. Alse remove checking @addr
less than 0 because addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on frv

Use new 'regno', 'datap' variables in order to remove duplicated
expressions and unnecessary castings. Alse remove checking @addr
less than 0 because addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on cris

Use new 'regno' variable in order to remove redandunt expression and
remove checking @addr less than 0 because @addr is now unsigned.  Also
update 'datap' on PTRACE_GET/SETREGS to fix a bug on arch-v10.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() and friends on Blackfin

Change signature of get/put_reg() according to the change of arch_ptrace()
and remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on avr32

use new 'datap' variable type of void pointer in order to remove unnecessary
castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on ARM

use new 'datap' variable in order to remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup arch_ptrace() on x86

Remove checking @addr less than 0 because @addr is now unsigned and
use new udescp variable in order to remove unnecessary castings.

[akpm@linux-foundation.org: fix unused variable 'udescp']
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: change signature of arch_ptrace()

Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: cleanup ptrace_request()

Use new 'datavp' and 'datalp' variables to remove unnecesary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: change signature of sys_ptrace() and friends

Since userspace API of ptrace syscall defines @addr and @data as void
pointers, it would be more appropriate to define them as unsigned long in
kernel.  Therefore related functions are changed also.

'unsigned long' is typically used in other places in kernel as an opaque
data type and that using this helps cleaning up a lot of warnings from
sparse.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: annotate lock context change on exit_ptrace()

exit_ptrace() releases and regrabs tasklist_lock but was missing proper
annotation.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: generic filestat update interface

This patch extracts the core logic from mem_cgroup_update_file_mapped() as
mem_cgroup_update_file_stat() and adds a wrapper.

As a planned future update, memory cgroup has to count dirty pages to
implement dirty_ratio/limit.  And more, the number of dirty pages is
required to kick flusher thread to start writeback.  (Now, no kick.)

This patch is preparation for it and makes other statistics implementation
clearer.  Just a clean up.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: cpu hotplug aware quick acount_move detection

An event counter MEM_CGROUP_ON_MOVE is used for quick check whether file
stat update can be done in async manner or not.  Now, it use percpu
counter and for_each_possible_cpu to update.

This patch replaces for_each_possible_cpu to for_each_online_cpu and adds
necessary synchronization logic at CPU HOTPLUG.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: cpu hotplug aware percpu count updates

Now, memcgroup's per cpu coutner uses for_each_possible_cpu() to get the
value.  It's better to use for_each_online_cpu() and a cpu hotplug
handler.

This patch only handles statistics counter.  MEM_CGROUP_ON_MOVE will be
handled in another patch.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: use for_each_mem_cgroup

In memory cgroup management, we sometimes have to walk through
subhierarchy of cgroup to gather informaiton, or lock something, etc.

Now, to do that, mem_cgroup_walk_tree() function is provided.  It calls
given callback function per cgroup found.  But the bad thing is that it
has to pass a fixed style function and argument, "void*" and it adds much
type casting to memcontrol.c.

To make the code clean, this patch replaces walk_tree() with

  for_each_mem_cgroup_tree(iter, root)

An iterator style call.  The good point is that iterator call doesn't have
to assume what kind of function is called under it.  A bad point is that
it may cause reference-count leak if a caller use "break" from the loop by
mistake.

I think the benefit is larger.  The modified code seems straigtforward and
easy to read because we don't have misterious callbacks and pointer cast.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: avoid lock in updating file_mapped (Was fix race in file_mapped accouting flag management

At accounting file events per memory cgroup, we need to find memory cgroup
via page_cgroup->mem_cgroup.  Now, we use lock_page_cgroup() for guarantee
pc->mem_cgroup is not overwritten while we make use of it.

But, considering the context which page-cgroup for files are accessed,
we can use alternative light-weight mutual execusion in the most case.

At handling file-caches, the only race we have to take care of is "moving"
account, IOW, overwriting page_cgroup->mem_cgroup.  (See comment in the
patch)

Unlike charge/uncharge, "move" happens not so frequently. It happens only when
rmdir() and task-moving (with a special settings.)
This patch adds a race-checker for file-cache-status accounting v.s. account
moving. The new per-cpu-per-memcg counter MEM_CGROUP_ON_MOVE is added.
The routine for account move
  1. Increment it before start moving
  2. Call synchronize_rcu()
  3. Decrement it after the end of moving.
By this, file-status-counting routine can check it needs to call
lock_page_cgroup(). In most case, I doesn't need to call it.

Following is a perf data of a process which mmap()/munmap 32MB of file cache
in a minute.

Before patch:
    28.25%     mmap  mmap               [.] main
    22.64%     mmap  [kernel.kallsyms]  [k] page_fault
     9.96%     mmap  [kernel.kallsyms]  [k] mem_cgroup_update_file_mapped
     3.67%     mmap  [kernel.kallsyms]  [k] filemap_fault
     3.50%     mmap  [kernel.kallsyms]  [k] unmap_vmas
     2.99%     mmap  [kernel.kallsyms]  [k] __do_fault
     2.76%     mmap  [kernel.kallsyms]  [k] find_get_page

After patch:
    30.00%     mmap  mmap               [.] main
    23.78%     mmap  [kernel.kallsyms]  [k] page_fault
     5.52%     mmap  [kernel.kallsyms]  [k] mem_cgroup_update_file_mapped
     3.81%     mmap  [kernel.kallsyms]  [k] unmap_vmas
     3.26%     mmap  [kernel.kallsyms]  [k] find_get_page
     3.18%     mmap  [kernel.kallsyms]  [k] __do_fault
     3.03%     mmap  [kernel.kallsyms]  [k] filemap_fault
     2.40%     mmap  [kernel.kallsyms]  [k] handle_mm_fault
     2.40%     mmap  [kernel.kallsyms]  [k] do_page_fault

This patch reduces memcg's cost to some extent.
(mem_cgroup_update_file_mapped is called by both of map/unmap)

Note: It seems some more improvements are required..but no idea.
      maybe removing set/unset flag is required.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: fix race in file_mapped accouting flag management

Presently memory cgroup accounts file-mapped by counter and flag.  counter
is working in the same way with zone_stat but FileMapped flag only exists
in memcg (for helping move_account).

This flag can be updated wrongly in a case.  Assume CPU0 and CPU1 and a
thread mapping a page on CPU0, another thread unmapping it on CPU1.

    CPU0                    CPU1
rmv rmap (mapcount 1->0)
   add rmap (mapcount 0->1)
   lock_page_cgroup()
   memcg counter+1 (some delay)
   set MAPPED FLAG.
   unlock_page_cgroup()
lock_page_cgroup()
memcg counter-1
clear MAPPED flag

In the above sequence counter is properly updated but FLAG is not.  This
means that representing a state by a flag which is maintained by counter
needs some special care.

To handle this, when clearing a flag, this patch check mapcount directly
and clear the flag only when mapcount == 0.  (if mapcount >0, someone will
make it to zero later and flag will be cleared.)

Reverse case, dec-after-inc cannot be a problem because page_table_lock()
works well for it.  (IOW, to make above sequence, 2 processes should touch
the same page at once with map/unmap.)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: notify ns_cgroup deprecated

The ns_cgroup will be removed very soon.  Let's warn, for this version,
ns_cgroup is deprecated.

Make ns_cgroup and clone_children exclusive.  If the clone_children is set
and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup
subsys is created (a printk will help the user to understand why the
creation fails).

Update the feature remove schedule file with the deprecated ns_cgroup.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroups: add check for strcpy destination string overflow

Function "strcpy" is used without check for maximum allowed source string
length and could cause destination string overflow.  Check for string
length is added before using "strcpy".  Function now is return error if
source string length is more than a maximum.

akpm: presently considered NotABug, but add the check for general
future-safeness and robustness.

Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: make the mount options parsing more accurate

Current behavior:
=================

(1) When we mount a cgroup, we can specify the 'all' option which
    means to enable all the cgroup subsystems.  This is the default option
    when no option is specified.

(2) If we want to mount a cgroup with a subset of the supported cgroup
    subsystems, we have to specify a subsystems name list for the mount
    option.

(3) If we specify another option like 'noprefix' or 'release_agent',
    the actual code wants the 'all' or a subsystem name option specified
    also.  Not critical but a bit not friendly as we should assume (1) in
    this case.

(4) Logically, the 'all' option is mutually exclusive with a subsystem
    name, but this is not detected.

In other words:
 succeed : mount -t cgroup -o all,freezer cgroup /cgroup
=> is it 'all' or 'freezer' ?
 fails : mount -t cgroup -o noprefix cgroup /cgroup
=> succeed if we do '-o noprefix,all'

The following patches consolidate a bit the mount options check.

New behavior:
=============

(1) untouched
(2) untouched
(3) the 'all' option will be by default when specifying other than
    a subsystem name option
(4) raises an error

In other words:
 fails   : mount -t cgroup -o all,freezer cgroup /cgroup
 succeed : mount -t cgroup -o noprefix cgroup /cgroup

For the sake of lisibility, the if ... then ... else ... if ...
indentation when parsing the options has been changed to:
if ... then
...
continue
fi

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup: add clone_children control file

The ns_cgroup is a control group interacting with the namespaces.  When a
new namespace is created, a corresponding cgroup is automatically created
too.  The cgroup name is the pid of the process who did 'unshare' or the
child of 'clone'.

This cgroup is tied with the namespace because it prevents a process to
escape the control group and use the post_clone callback, so the child
cgroup inherits the values of the parent cgroup.

Unfortunately, the more we use this cgroup and the more we are facing
problems with it:

(1) when a process unshares, the cgroup name may conflict with a
    previous cgroup with the same pid, so unshare or clone return -EEXIST

(2) the cgroup creation is out of control because there may have an
    application creating several namespaces where the system will
    automatically create several cgroups in his back and let them on the
    cgroupfs (eg.  a vrf based on the network namespace).

(3) the mix of (1) and (2) force an administrator to regularly check
    and clean these cgroups.

This patchset removes the ns_cgroup by adding a new flag to the cgroup and
the cgroupfs mount option.  It enables the copy of the parent cgroup when
a child cgroup is created.  We can then safely remove the ns_cgroup as
this flag brings a compatibility.  We have now to manually create and add
the task to a cgroup, which is consistent with the cgroup framework.

This patch:

Sent as an answer to a previous thread around the ns_cgroup.

https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html

It adds a control file 'clone_children' for a cgroup.  This control file
is a boolean specifying if the child cgroup should be a clone of the
parent cgroup or not.  The default value is 'false'.

This flag makes the child cgroup to call the post_clone callback of all
the subsystem, if it is available.

At present, the cpuset is the only one which had implemented the
post_clone callback.

The option can be set at mount time by specifying the 'clone_children'
mount option.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup_freezer: update_freezer_state() does incorrect state transitions

There are 4 state transitions possible for a freezer.  Only FREEZING ->
FROZEN transaction is done lazily.  This patch allows update_freezer_state
only to perform this transaction and renames the function to
update_if_frozen.

Moreover is_task_frozen_enough function is removed and its every occurence
is replaced with frozen().  Therefore for a group to become FROZEN every
task must be frozen.

The previous version could trigger a following bug: When cgroup is in the
process of freezing (but none of its tasks are frozen yet),
update_freezer_state() (called from freezer_read or freezer_write) would
incorrectly report that a group is 'THAWED' (because nfrozen = 0),
allowing the transaction FREEZING -> THAWED without writing anything to
'freezer.state'.  This is incorrect according to the documentation.  This
could result in a 'THAWED' cgroup with frozen tasks inside.

A code to reproduce this bug is available here:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug2.c

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup_freezer: fix can_attach() to prohibit moving from/to freezing/frozen cgroups

It is possible to move a task from its cgroup even if this group is
'FREEZING'.  This results in a nasty bug - the moved task will become
frozen OUTSIDE its original cgroup and will remain in a permanent 'D'
state.

This patch allows to migrate the task only between THAWED cgroups.

This behavior was observed and easily reproduced on a single core laptop.
Notice that reproducibility depends highly on the machine used.  Program
and instructions how to reproduce the bug can be fetched from:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug.c

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cgroup_freezer: unnecessary test in cgroup_freezing_or_frozen()

The root freezer_state is always CGROUP_THAWED so we can remove the
special case from the code.  The test itself can be handy and is extracted
to static function.

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

doc: clarify the behaviour of dirty_ratio/dirty_bytes

When dirty_ratio or dirty_bytes is written the other parameter is disabled
and set to 0 (in dirty_bytes_handler() / dirty_ratio_handler()).

We do the same for dirty_background_ratio and dirty_background_bytes.

However, in the sysctl documentation, we say that the counterpart becomes
a function of the old value, that is not correct.

Clarify the documentation reporting the actual behaviour.

Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

isofs: work-around for Rock Ridge+Joliet CDs with empty ISO root directory

If a CD has both Rock Ridge and Joliet extensions and the ISO root
directory is empty, no files are visible.  Disable Rock Ridge extensions
in this case and use Joliet root directory instead.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/omap/blizzard.c: suspected typo in assignment

Untested, but looks like an obvious typo to me.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Cc: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/gbefb.c: eliminate memory leak

This code is preceded by a call to framebuffer_alloc, which allocates
memory, so this memory should be freed before leaving the function in an
error case.  out_release_framebuffer just frees the frame buffer and
returns.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression x;
expression E;
identifier f1;
iterator I;
@@

x = framebuffer_alloc(...);
<... when != x
     when != true (x == NULL || ...)
     when != if (...) { <+...x...+> }
     when != I (...) { <+...x...+> }
(
 x == NULL
|
 x == E
|
 x->f1
)
...>
* return ...;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fbmem: fix fb_read, fb_write unaligned accesses

fb_{read,write} access the framebuffer using lots of fb_{read,write}l's
but don't check that the file position is aligned which can cause problems
on some architectures which do not support unaligned accesses.

Since the operations are essentially memcpy_{from,to}io, new
fb_memcpy_{from,to}fb macros have been defined and these are used instead.

For Sparc, fb_{read,write} macros use sbus_{read,write}, so this defines
new sbus_memcpy_{from,to}io functions the same as memcpy_{from,to}io but
using sbus_{read,write}b instead of {read,write}b.

Signed-off-by: James Hogan <james@albanarts.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fbmem: fix whitespace

Change a few lines of indentation to tabs.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/matrox/matroxfb_maven.c: fix unsigned return type

The function has an unsigned return type, but returns a negative constant
to indicate an error condition.  The result of calling the function is
only tested by comparison to 0, and thus unsigned is not needed and can be
dropped from the return type.

A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@exists@
identifier f;
constant C;
@@

 unsigned f(...)
 { <+...
*  return -C;
 ...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

savagefb: fix DDC for Savage 4

I tested savagefb on 3 different Savage 4 cards:
Diamond Stealth III S520
Number Nine SR9
Datapath Horizon 2S (two savage chips on a PCI card)

it worked except the DDC which did not work on any of them.

Looking at the BIOS code, it does not use MMIO register 0xff20 but CRT
register 0xa0 or 0xb1 - depending on the chip revision and something in
register 0xa6.  With this patch, DDC works fine on all 3 cards (even on
the second head of Horizon 2S - although it does not display anything as
it's misconfigured because of missing BIOS).

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/matrox/matroxfb_DAC1064.c: remove undead ifdef CONFIG_FB_MATROX_G

The CONFIG_FB_MATROX_G ifdef isn't necessary at this point, because it is
checked in an outer ifdef level already and has no effect here.

Signed-off-by: Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

langwell_gpio: add support for whitney point

In this case the logic is very similar but the IRQs are not exposed and
the device is not picked up via PCI

Based on a separate internal whitney point driver by Yin Kangkai.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Yin Kangkai <kangkai.yin@intel.com>
Cc: Alek Du <alek.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/langwell_gpio.c: remove semicolons after function definitions

Deweird this driver.

Cc: Alek Du <alek.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: add Topcliff PCH GPIO driver

Topcliff PCH is the platform controller hub that is going to be used in
Intel's upcoming general embedded platform.  All IO peripherals in
Topcliff PCH are actually devices sitting on AMBA bus.  Topcliff PCH has
GPIO I/F.  Using this I/F, it is able to access system devices connected
to GPIO.

[akpm@linux-foundation.org: ese DEFINE_PCI_DEVICE_TABLE (per Joe Perches)]
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Tomoya MORINAGA <morinaga526@dsn.okisemi.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: adp5588-gpio: add i2c forward declaration

Some ADP5588 functions take a pointer to an i2c_client, but if the i2c
header doesn't happen to be included first, we hit the standard "struct
declared inside parameter list" warnings from gcc.  So add a simple
forward decl of the i2c_client struct.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: adp5588-gpio: gpio_start must be signed

Common code interprets this as a signed value (a negative value is used to
request dynamic ID allocation), so make sure the platform data has proper
types to support that.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: adp5588-gpio: support interrupt controller

Implement irq_chip functionality on ADP5588/5587 GPIO expanders.  Only
level sensitive interrupts are supported.  Interrupts provided by this
irq_chip must be requested using request_threaded_irq().

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: add support for 74x164 serial-in/parallel-out 8-bit shift register

Add support for generic 74x164 serial-in/parallel-out 8-bits shift
register.  This driver can be used as a GPIO output expander.

[akpm@linux-foundation.org: remove unused local `refresh']
Signed-off-by: Miguel Gaio <miguel.gaio@efixo.com>
Signed-off-by: Juhos Gabor <juhosg@openwrt.org>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>