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>

This patch does the compat_sys_ptrace conversion for parisc.
In addition it does convert the parisc ptrace code to use the
architecture-independent ptrace infrastructure instead of own coding.
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

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>

struct stat / compat_stat is the same on all architectures, so
cp_compat_stat should be, too.

Turns out it is, except that various architectures have slightly and some
high2lowuid/high2lowgid or the direct assignment instead of the
SET_UID/SET_GID that expands to the correct one anyway.

This patch replaces the arch-specific cp_compat_stat implementations with
a common one based on the x86-64 one.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ]
Acked-by: Kyle McMartin <kyle@mcmartin.ca> [ parisc bits ]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The SET_PERSONALITY macro is always called with a second argument of 0.
Remove the ibcs argument and the various tests to set the PER_SVR4
personality.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

The unwinder was being initialized way too late to be any use
debugging early boot crashes. Instead of relying on module_init
initcalls to initialize it, let's do it explicitly as early as
we can.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Bang in our own start_parisc call, which initializes the PDC
width, and turns on the FPU.

Previously, if CONFIG_PRINTK_TIME was on, we'd attempt to use
the FPU before we had enabled it, resulting in a difficult
to diagnose panic.

This patch causes init_per_cpu to redundantly set these for
cpu0, but this is harmless.

These functions are called only when bringing up the monarch cpu,
so it is safe to call them without taking the pdc spinlock. In the
future, this may become relevant for lockdep, since these functions were
taking spinlocks before start_kernel called the lockdep initializers.

It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24.  However,
the current way its coded doesn't work on parisc64.  For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors

Make dereference_function_descriptor() more accommodating by allowing
architecture overrides.  I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NTony Luck <tony.luck@intel.com>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't need this any more; arguably we never really did.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

A parisc allmodconfig build produces this:

arch/parisc/hpux/fs.c:107: error: 'buffer' undeclared (first use in this function)

Introduced by commit da574983 ("[PATCH]
fix hpux_getdents()").

Helge Dille also reported this in bugzilla 11461:

	http://bugzilla.kernel.org/show_bug.cgi?id=11461

and he posted an identical patch.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Missing checks for -EFAULT, broken handling of overflow.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* do not pass nameidata; struct path is all the callers want.
* switch to new helpers:
	user_path_at(dfd, pathname, flags, &path)
	user_path(pathname, &path)
	user_lpath(pathname, &path)
	user_path_dir(pathname, &path)  (fail if not a directory)
  The last 3 are trivial macro wrappers for the first one.
* remove nameidata in callers.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch introduces the new syscall pipe2 which is like pipe but it also
takes an additional parameter which takes a flag value.  This patch implements
the handling of O_CLOEXEC for the flag.  I did not add support for the new
syscall for the architectures which have a special sys_pipe implementation.  I
think the maintainers of those archs have the chance to go with the unified
implementation but that's up to them.

The implementation introduces do_pipe_flags.  I did that instead of changing
all callers of do_pipe because some of the callers are written in assembler.
I would probably screw up changing the assembly code.  To avoid breaking code
do_pipe is now a small wrapper around do_pipe_flags.  Once all callers are
changed over to do_pipe_flags the old do_pipe function can be removed.

The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>

#ifndef __NR_pipe2
# ifdef __x86_64__
#  define __NR_pipe2 293
# elif defined __i386__
#  define __NR_pipe2 331
# else
#  error "need __NR_pipe2"
# endif
#endif

int
main (void)
{
  int fd[2];
  if (syscall (__NR_pipe2, fd, 0) != 0)
    {
      puts ("pipe2(0) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      int coe = fcntl (fd[i], F_GETFD);
      if (coe == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if (coe & FD_CLOEXEC)
        {
          printf ("pipe2(0) set close-on-exit for fd[%d]\n", i);
          return 1;
        }
    }
  close (fd[0]);
  close (fd[1]);

  if (syscall (__NR_pipe2, fd, O_CLOEXEC) != 0)
    {
      puts ("pipe2(O_CLOEXEC) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      int coe = fcntl (fd[i], F_GETFD);
      if (coe == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if ((coe & FD_CLOEXEC) == 0)
        {
          printf ("pipe2(O_CLOEXEC) does not set close-on-exit for fd[%d]\n", i);
          return 1;
        }
    }
  close (fd[0]);
  close (fd[1]);

  puts ("OK");

  return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Acked-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

free_area_init_node() gets passed in the node id as well as the node
descriptor.  This is redundant as the function can trivially get the node
descriptor itself by means of NODE_DATA() and the node's id.

I checked all the users and NODE_DATA() seems to be usable everywhere
from where this function is called.
Signed-off-by: NJohannes Weiner <hannes@saeurebad.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are a lot of places that define either a single bootmem descriptor or an
array of them.  Use only one central array with MAX_NUMNODES items instead.
Signed-off-by: NJohannes Weiner <hannes@saeurebad.de>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This converts parisc to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single(). Tested by
Kyle, seems to work.

Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Thankfully, the values were irrelevant... Spotted by
newer gcc.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Needed by ext4 when built as a module.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Needed by fuse (via copy_highpage).
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

And explicitly list it in vmlinux.lds...
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

This reverts commit bd3bb8c1.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

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

Missing <linux/init.h> header for __HEAD macro.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

This work enables us to remove -traditional from $AFLAGS on
parisc.
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

The functions time_before, time_before_eq, time_after, and time_after_eq are
more robust for comparing jiffies against other values.

So use the time_after() macro, defined in linux/jiffies.h, which deals with
wrapping correctl

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NS.Caglar Onur <caglar@pardus.org.tr>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

show_mem() has no need to print the amount of free swap space manually because
show_free_areas() does this already and is called by the former.

The two outputs only differ in text formatting:

  printk("Free swap  = %lukB\n", ...);
  printk("Free swap:       %6ldkB\n", ...);
Signed-off-by: NJohannes Weiner <hannes@saeurebad.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

This trivial patch fixes the following section warnings on PARISC:
> WARNING: vmlinux.o (.text.1): unexpected section name.
>The (.[number]+) following section name are ld generated and not expected.
> Did you forget to use "ax"/"aw" in a .S file?
> Note that for example <linux/init.h> contains
> section definitions for use in .S files.
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

PA-RISC to aid debugging prints out the zonelists setup by the system.  A
bad call to node_zonelist() breaks at compile-time.  This patch fixes it.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This replaces the duplicated arch-specific versions of "sys_pipe()" with
one unified implementation.  This removes almost 250 lines of duplicated
code.

It's marked __weak, so that *if* an architecture wants to override the
default implementation it can do so by simply having its own replacement
version, since many architectures use alternate calling conventions for
the 'pipe()' system call for legacy reasons (ie traditional UNIX
implementations often return the two file descriptors in registers)

I still haven't changed the cris version even though Linus says the BKL
isn't needed.  The arch maintainer can easily do it if there are really
no obstacles.
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>