* get rid of fake struct file/struct dentry in __blkdev_get()
* merge __blkdev_get() and do_open()
* get rid of flags argument of blkdev_get()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This fixes

  kernel/kexec.c: In function 'crash_save_vmcoreinfo_init':
  kernel/kexec.c:1374: error: 'vmlist' undeclared (first use in this function)
  kernel/kexec.c:1374: error: (Each undeclared identifier is reported only once
  kernel/kexec.c:1374: error: for each function it appears in.)
  kernel/kexec.c:1410: error: invalid use of undefined type 'struct vm_struct'
  make[1]: *** [kernel/kexec.o] Error 1
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A consolidated implementation will provide this generically through
asm/byteorder, remove direct includes to avoid breakage when the
changeover to the new implementation occurs.

This hunk was lost from commit 1d8cca44
("byteorder: provide swabb.h generically in asm/byteorder.h")
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A consolidated implementation will provide this generically through
asm/byteorder, remove direct includes to avoid breakage when the
changeover to the new implementation occurs.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Acked-by: NMauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the symbols 'vmlist' and offset 'vm_struct.addr' to the vmcoreinfo[1]
data for i386 vmalloc translation.

makedumpfile[2] needs VMALLOC_START value for distinguishing a vmalloc
address or not, because it should choose suitable translation method.  If
applying this patch, makedumpfile will be able to take VMALLOC_START value
from 'vmlist.addr'.

vmcoreinfo[1]:
The vmcoreinfo data has the minimum debugging information only for dump
filtering. makedumpfile[2] uses it to distinguish unnecessary pages and
creates a small dumpfile.

makedumpfile[2]:
dump filtering command
https://sourceforge.net/projects/makedumpfile/Signed-off-by: NKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that wait_task_inactive(task, state) checks task->state == state,
we can simplify the code and make this debugging check more robust.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ptrace_untrace() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1) seq_file excepts that m->count == m->size when it's buf is full,
   so current code will causes bugs when buf is overflow.

2) There is not too good that cpuset accesses struct seq_file's
   fields directly.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: NPaul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the use of int cpus_nonempty variable from 'update_flag' function.
Signed-off-by: NMd.Rakib H. Mullick <rakib.mullick@gmail.com>
Acked-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rather than pre-generating the entire text for the "tasks" file each
time the file is opened, we instead just generate/update the array of
process ids and use a seq_file to report these to userspace.  All open
file handles on the same "tasks" file can share a pid array, which may
be updated any time that no thread is actively reading the array.  By
sharing the array, the potential for userspace to DoS the system by
opening many handles on the same "tasks" file is removed.

[Based on a patch by Lai Jiangshan, extended to use seq_file]
Signed-off-by: NPaul Menage <menage@google.com>
Reviewed-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

put_css_set_taskexit may be called when find_css_set is called on other
cpu.  And the race will occur:

put_css_set_taskexit side                    find_css_set side

                                        |
atomic_dec_and_test(&kref->refcount)    |
    /* kref->refcount = 0 */            |
....................................................................
                                        |  read_lock(&css_set_lock)
                                        |  find_existing_css_set
                                        |  get_css_set
                                        |  read_unlock(&css_set_lock);
....................................................................
__release_css_set                       |
....................................................................
                                        | /* use a released css_set */
                                        |

[put_css_set is the same. But in the current code, all put_css_set are
put into cgroup mutex critical region as the same as find_css_set.]

[akpm@linux-foundation.org: repair comments]
[menage@google.com: eliminate race in css_set refcounting]
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These comments are useless, remove them.
Signed-off-by: NWANG Cong <wangcong@zeuux.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

check_if_frozen() sounds like it should return something when in fact it's
just updating the freezer state.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename cgroup freezer states to be less generic to avoid any name
collisions while also better describing what each state is.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't let frozen tasks or cgroups change.  This means frozen tasks can't
leave their current cgroup for another cgroup.  It also means that tasks
cannot be added to or removed from a cgroup in the FROZEN state.  We
enforce these rules by checking for frozen tasks and cgroups in the
can_attach() function.
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a system is resumed after a suspend, it will also unfreeze frozen
cgroups.

This patchs modifies the resume sequence to skip the tasks which are part
of a frozen control group.
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
Tested-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements a new freezer subsystem in the control groups
framework.  It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.

The freezer subsystem in the container filesystem defines a file named
freezer.state.  Writing "FROZEN" to the state file will freeze all tasks
in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup.  Reading will return the current state.

* Examples of usage :

   # mkdir /containers/freezer
   # mount -t cgroup -ofreezer freezer  /containers
   # mkdir /containers/0
   # echo $some_pid > /containers/0/tasks

to get status of the freezer subsystem :

   # cat /containers/0/freezer.state
   RUNNING

to freeze all tasks in the container :

   # echo FROZEN > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   FREEZING
   # cat /containers/0/freezer.state
   FROZEN

to unfreeze all tasks in the container :

   # echo RUNNING > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   RUNNING

This is the basic mechanism which should do the right thing for user space
task in a simple scenario.

It's important to note that freezing can be incomplete.  In that case we
return EBUSY.  This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time.  After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read.  The state will remain
"FREEZING" until one of these things happens:

	1) Userspace cancels the freezing operation by writing "RUNNING" to
		the freezer.state file
	2) Userspace retries the freezing operation by writing "FROZEN" to
		the freezer.state file (writing "FREEZING" is not legal
		and returns EIO)
	3) The tasks that blocked the cgroup from entering the "FROZEN"
		state disappear from the cgroup's set of tasks.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
Tested-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the TIF_FREEZE flag is available in all architectures, extract
the refrigerator() and freeze_task() from kernel/power/process.c and make
it available to all.

The refrigerator() can now be used in a control group subsystem
implementing a control group freezer.
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
Tested-by: NMatt Helsley <matthltc@us.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds a function to scan individual or all zones' unevictable
lists and move any pages that have become evictable onto the respective
zone's inactive list, where shrink_inactive_list() will deal with them.

Adds sysctl to scan all nodes, and per node attributes to individual
nodes' zones.

Kosaki: If evictable page found in unevictable lru when write
/proc/sys/vm/scan_unevictable_pages, print filename and file offset of
these pages.

[akpm@linux-foundation.org: fix one CONFIG_MMU=n build error]
[kosaki.motohiro@jp.fujitsu.com: adapt vmscan-unevictable-lru-scan-sysctl.patch to new sysfs API]
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The base address of a (per cpu) clock base is a useful debug info.
Add it and bump the version number of timer_lists.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The per cpu clock events device output of timer_list lacks an
association of the device to the cpu which is annoying when looking at
the output of /proc/timer_list from a 128 way system. 

Add the CPU number info and mark the broadcast device in the device
list printout.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The current timer_list output prints the address of the on stack copy
of the active hrtimer instead of the hrtimer itself.

Print the address of the real timer instead.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We did not restart the tick device from irq_enter() to avoid double
reprogramming and extra events in the return immediate to idle case.

But long lasting softirqs can lead to a situation where jiffies become
stale:

idle()
  tick stopped (reprogrammed to next pending timer)
  halt()
   interrupt
     jiffies updated from irq_enter()
     interrupt handler
     softirq function 1 runs 20ms
     softirq function 2 arms a 10ms timer with a stale jiffies value
     jiffies updated from irq_exit()
     timer wheel has now an already expired timer
     (the one added in function 2)
     timer fires and timer softirq runs

This was discovered when debugging a timer problem which happend only
when the ath5k driver is active. The debugging proved that there is a
softirq function running for more than 20ms, which is a bug by itself.

To solve this we restart the tick timer right from irq_enter(), but do
not go through the other functions which are necessary to return from
idle when need_resched() is set.
Reported-by: NElias Oltmanns <eo@nebensachen.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NElias Oltmanns <eo@nebensachen.de>

Split out the clock event device reprogramming. Preparatory
patch.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We have two separate nohz function calls in irq_enter() for no good
reason. Just call a single NOHZ function from irq_enter() and call
the bits in the tick code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This is basically a genericization of Jens Axboe's block layer
remote softirq changes.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This fixes the broken 77af7e34
("softirq, warning fix: correct a format to avoid a warning") fix
correctly.

The type of a pointer subtraction is not "int", nor is it "long".  It
can be either (or something else).  It's "ptrdiff_t", and the printk
format for it is "%td".

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make the needlessly global kretprobe_table_lock() static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No functional change.  Just return NULL for kzalloc failure immediately,
rather than wrapping the whole function body in the body of an "if".
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patchs adds the CONFIG_AIO option which allows to remove support
for asynchronous I/O operations, that are not necessarly used by
applications, particularly on embedded devices. As this is a
size-reduction option, it depends on CONFIG_EMBEDDED. It allows to
save ~7 kilobytes of kernel code/data:

   text	   data	    bss	    dec	    hex	filename
1115067	 119180	 217088	1451335	 162547	vmlinux
1108025	 119048	 217088	1444161	 160941	vmlinux.new
  -7042    -132       0   -7174   -1C06 +/-

This patch has been originally written by Matt Mackall
<mpm@selenic.com>, and is part of the Linux Tiny project.

[randy.dunlap@oracle.com: build fix]
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

name and nlen parameters passed to ->strategy hook are unused, remove
them.  In general ->strategy hook should know what it's doing, and don't
do something tricky for which, say, pointer to original userspace array
may be needed (name).
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ]
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nothing arch specific in get/settimeofday.  The details of the timeval
conversion varied a little from arch to arch, but all with the same
results.

Also add an extern declaration for sys_tz to linux/time.h because externs
in .c files are fowned upon.  I'll kill the externs in various other files
in a sparate patch.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ]
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add documentation in kerneldoc for new printk format extensions

This patch documents the new %pS/%pF options in printk in kernel doc.

Hope I didn't miss any other extension.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move print_tainted() kernel-doc to avoid the following error:

Error(/var/linsrc/mmotm-2008-1002-1617//kernel/panic.c:155): cannot understand prototype: 'struct tnt '
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

People can use the real name an an index into MAINTAINERS to find the
current email address.
Signed-off-by: NFrancois Cami <francois.cami@free.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 6dd06c9f ("module: make
module_address_lookup safe") introduced double returns in the function
kallsyms_lookup(), it's weird.  The second one should be removed.
Signed-off-by: NWANG Cong <wangcong@zeuux.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

utsname() is quite expensive to calculate.  Cache it in a local.

          text    data     bss     dec     hex filename
before:  11136     720      16   11872    2e60 kernel/sys.o
after:   11096     720      16   11832    2e38 kernel/sys.o
Acked-by: NVegard Nossum <vegard.nossum@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: N"Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On sethostname() and setdomainname(), previous information may be retained
if it was longer than than the new hostname/domainname.

This can be demonstrated trivially by calling sethostname() first with a
long name, then with a short name, and then calling uname() to retrieve
the full buffer that contains the hostname (and possibly parts of the old
hostname), one just has to look past the terminating zero.

I don't know if we should really care that much (hence the RFC); the only
scenarios I can possibly think of is administrator putting something
sensitive in the hostname (or domain name) by accident, and changing it
back will not undo the mistake entirely, though it's not like we can
recover gracefully from "rm -rf /" either...  The other scenario is
namespaces (CLONE_NEWUTS) where some information may be unintentionally
"inherited" from the previous namespace (a program wants to hide the
original name and does clone + sethostname, but some information is still
left).

I think the patch may be defended on grounds of the principle of least
surprise.  But I am not adamant :-)

(I guess the question now is whether userspace should be able to
write embedded NULs into the buffer or not...)

At least the observation has been made and the patch has been presented.
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>