Commit graph

6320 commits

Author SHA1 Message Date
Eric Paris
318b6d3d7d audit: incorrect ref counting in audit tree tag_chunk
tag_chunk has bad exit paths in which the inotify ref counting is wrong.
At the top of the function we found &old_watch using  inotify_find_watch().
inotify_find_watch takes a reference to the watch.  This is never dropped
on an error path.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:48:26 -04:00
Paul Moore
6d208da89a audit: Fix possible return value truncation in audit_get_context()
The audit subsystem treats syscall return codes as type long, unfortunately
the audit_get_context() function mistakenly converts the return code to an
int type in the parameters which could cause problems on systems where the
sizeof(int) != sizeof(long).

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:46:19 -04:00
Miloslav Trmac
55ad2f8d34 audit: ignore terminating NUL in AUDIT_USER_TTY messages
AUDIT_USER_TTY, like all other messages sent from user-space, is sent
NUL-terminated.  Unlike other user-space audit messages, which come only
from trusted sources, AUDIT_USER_TTY messages are processed using
audit_log_n_untrustedstring().

This patch modifies AUDIT_USER_TTY handling to ignore the trailing NUL
and use the "quoted_string" representation of the message if possible.

Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:43:36 -04:00
Miloslav Trmac
b3897f5671 Audit: fix handling of 'strings' with NULL characters
currently audit_log_n_untrustedstring() uses audit_string_contains_control()
to check if the 'string' has any control characters.  If the 'string' has an
embedded NULL audit_string_contains_control() will return that the data has
no control characters and will then pass the string to audit_log_n_string
with the total length, not the length up to the first NULL.
audit_log_n_string() does a memcpy of the entire length and so the actual
audit record emitted may then contain a NULL and then whatever random memory
is after the NULL.

Since we want to log the entire octet stream (if we can't trust the data
to be a string we can't trust that a NULL isn't actually a part of it)
we should just consider NULL as a control character.  If the caller is
certain they want to stop at the first NULL they should be using
audit_log_untrustedstring.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:43:24 -04:00
Zhenwen Xu
c28bb7da74 make the e->rule.xxx shorter in kernel auditfilter.c
make the e->rule.xxx shorter in kernel/auditfilter.c
--
---------------------------------
Zhenwen Xu - Open and Free
Home Page:	http://zhwen.org
My Studio:	http://dim4.cn

>From 99692dc640b278f1cb1a15646ce42f22e89c0f77 Mon Sep 17 00:00:00 2001
From: Zhenwen Xu <Helight.Xu@gmail.com>
Date: Thu, 12 Mar 2009 22:04:59 +0800
Subject: [PATCH] make the e->rule.xxx shorter in kernel/auditfilter.c

Signed-off-by: Zhenwen Xu <Helight.Xu@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:40:33 -04:00
Randy Dunlap
6b96255998 auditsc: fix kernel-doc notation
Fix auditsc kernel-doc notation:

Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): No description found for parameter 'attr'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): Excess function parameter 'u_attr' description in '__audit_mq_open'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): No description found for parameter 'notification'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): Excess function parameter 'u_notification' description in '__audit_mq_notify'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc:	Al Viro <viro@zeniv.linux.org.uk>
cc:	Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:39:19 -04:00
Jiri Pirko
ca96a895a6 audit: EXECVE record - removed bogus newline
(updated)
Added hunk that changes the comment, the rest is the same.

EXECVE records contain a newline after every argument. auditd converts
"\n" to " " so you cannot see newlines even in raw logs, but they're
there nevertheless. If you're not using auditd, you need to work round
them. These '\n' chars are can be easily replaced by spaces when
creating record in kernel. Note there is no need for trailing '\n' in
an audit record.

record before this patch:
"type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\"\na1=\"a\"\na2=\"b\"\na3=\"c\"\n"

record after this patch:
"type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\" a1=\"a\" a2=\"b\" a3=\"c\""

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-05 13:38:59 -04:00
Linus Torvalds
09f38dc19d Merge branch 'core-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ptrace: remove a useless goto
2009-04-03 17:35:06 -07:00
Linus Torvalds
30a39e0e97 Merge branch 'stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  symbols, stacktrace: look up init symbols after module symbols
2009-04-03 17:34:41 -07:00
Linus Torvalds
c7edad5fcb Merge branch 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: rcu_barrier VS cpu_hotplug: Ensure callbacks in dead cpu are migrated to online cpu
2009-04-03 17:34:12 -07:00
Linus Torvalds
b1dbb67911 Merge branch 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  s390: remove arch specific smp_send_stop()
  panic: clean up kernel/panic.c
  panic, smp: provide smp_send_stop() wrapper on UP too
  panic: decrease oops_in_progress only after having done the panic
  generic-ipi: eliminate WARN_ON()s during oops/panic
  generic-ipi: cleanups
  generic-ipi: remove CSD_FLAG_WAIT
  generic-ipi: remove kmalloc()
  generic IPI: simplify barriers and locking
2009-04-03 17:33:30 -07:00
Linus Torvalds
492f59f526 Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]
  lockdep: remove duplicate CONFIG_DEBUG_LOCKDEP definitions
  lockdep: require framepointers for x86
  lockdep: remove extra "irq" string
  lockdep: fix incorrect state name
2009-04-03 17:29:53 -07:00
Linus Torvalds
811158b147 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
  trivial: Update my email address
  trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
  trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
  trivial: Fix misspelling of "Celsius".
  trivial: remove unused variable 'path' in alloc_file()
  trivial: fix a pdlfush -> pdflush typo in comment
  trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
  trivial: wusb: Storage class should be before const qualifier
  trivial: drivers/char/bsr.c: Storage class should be before const qualifier
  trivial: h8300: Storage class should be before const qualifier
  trivial: fix where cgroup documentation is not correctly referred to
  trivial: Give the right path in Documentation example
  trivial: MTD: remove EOL from MODULE_DESCRIPTION
  trivial: Fix typo in bio_split()'s documentation
  trivial: PWM: fix of #endif comment
  trivial: fix typos/grammar errors in Kconfig texts
  trivial: Fix misspelling of firmware
  trivial: cgroups: documentation typo and spelling corrections
  trivial: Update contact info for Jochen Hein
  trivial: fix typo "resgister" -> "register"
  ...
2009-04-03 15:24:35 -07:00
David Howells
8f0aa2f25b Document the slow work thread pool
Document the slow work thread pool.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:35 +01:00
David Howells
12e22c5e4b Make the slow work pool configurable
Make the slow work pool configurable through /proc/sys/kernel/slow-work.

 (*) /proc/sys/kernel/slow-work/min-threads

     The minimum number of threads that should be in the pool as long as it is
     in use.  This may be anywhere between 2 and max-threads.

 (*) /proc/sys/kernel/slow-work/max-threads

     The maximum number of threads that should in the pool.  This may be
     anywhere between min-threads and 255 or NR_CPUS * 2, whichever is greater.

 (*) /proc/sys/kernel/slow-work/vslow-percentage

     The percentage of active threads in the pool that may be used to execute
     very slow work items.  This may be between 1 and 99.  The resultant number
     is bounded to between 1 and one fewer than the number of active threads.
     This ensures there is always at least one thread that can process very
     slow work items, and always at least one thread that won't.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:35 +01:00
David Howells
109d9272c4 Make slow-work thread pool actually dynamic
Make the slow-work thread pool actually dynamic in the number of threads it
contains.  With this patch, it will both create additional threads when it has
extra work to do, and cull excess threads that aren't doing anything.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:35 +01:00
David Howells
07fe7cb7c7 Create a dynamically sized pool of threads for doing very slow work items
Create a dynamically sized pool of threads for doing very slow work items, such
as invoking mkdir() or rmdir() - things that may take a long time and may
sleep, holding mutexes/semaphores and hogging a thread, and are thus unsuitable
for workqueues.

The number of threads is always at least a settable minimum, but more are
started when there's more work to do, up to a limit.  Because of the nature of
the load, it's not suitable for a 1-thread-per-CPU type pool.  A system with
one CPU may well want several threads.

This is used by FS-Cache to do slow caching operations in the background, such
as looking up, creating or deleting cache objects.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:35 +01:00
Linus Torvalds
8fe74cf053 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  Remove two unneeded exports and make two symbols static in fs/mpage.c
  Cleanup after commit 585d3bc06f
  Trim includes of fdtable.h
  Don't crap into descriptor table in binfmt_som
  Trim includes in binfmt_elf
  Don't mess with descriptor table in load_elf_binary()
  Get rid of indirect include of fs_struct.h
  New helper - current_umask()
  check_unsafe_exec() doesn't care about signal handlers sharing
  New locking/refcounting for fs_struct
  Take fs_struct handling to new file (fs/fs_struct.c)
  Get rid of bumping fs_struct refcount in pivot_root(2)
  Kill unsharing fs_struct in __set_personality()
2009-04-02 21:09:10 -07:00
Robin Holt
f5f7eac41d Allow rwlocks to re-enable interrupts
Pass the original flags to rwlock arch-code, so that it can re-enable
interrupts if implemented for that architecture.

Initially, make __raw_read_lock_flags and __raw_write_lock_flags stubs
which just do the same thing as non-flags variants.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
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>
2009-04-02 19:05:11 -07:00
Robin Holt
e8c158bb31 Factor out #ifdefs from kernel/spinlock.c to LOCK_CONTENDED_FLAGS
SGI has observed that on large systems, interrupts are not serviced for a
long period of time when waiting for a rwlock.  The following patch series
re-enables irqs while waiting for the lock, resembling the code which is
already there for spinlocks.

I only made the ia64 version, because the patch adds some overhead to the
fast path.  I assume there is currently no demand to have this for other
architectures, because the systems are not so large.  Of course, the
possibility to implement raw_{read|write}_lock_flags for any architecture
is still there.

This patch:

The new macro LOCK_CONTENDED_FLAGS expands to the correct implementation
depending on the config options, so that IRQ's are re-enabled when
possible, but they remain disabled if CONFIG_LOCKDEP is set.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
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>
2009-04-02 19:05:10 -07:00
Aravind Srinivasan
2c53d9109f relay: fix for possible loss/corruption of produced subbufs
Fix possible loss/corruption of produced subbufs in
relay_subbufs_consumed().

When buf->subbufs_produced wraps around after UINT_MAX and
buf->subbufs_consumed is still < UINT_MAX, the condition

	if (buf->subbufs_consumed > buf->subbufs_produced)

will be true even for certain valid values of subbufs_consumed.  This may
lead to loss or corruption of produced subbufs.

Signed-off-by: Aravind Srinivasan <raa.aars@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:05 -07:00
Dmitri Vorobiev
edb79a2132 kexec: vmcoreinfo_data[] can become static
The vmcoreinfo_data[] array is not used outside of kernel/kexec.c, and
can therefore become static. This patch adds the relevant keyword to the
definition of the array.

Noticed by sparse.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:04 -07:00
Neil Horman
04d491ab2a kexec: add dmesg log symbols to /proc/vmcoreinfo lists
It would be nice to be able to extract the dmesg log from a vmcore file
without needing to keep the debug symbols for the running kernel handy all
the time.  We have a facility to do this in /proc/vmcore.  This patch adds
the log_buf and log_end symbols to the vmcoreinfo area so that tools (like
makedumpfile) can easily extract the dmesg logs from a vmcore image.

[akpm@linux-foundation.org: several fixes and cleanups]
[akpm@linux-foundation.org: fix unused log_buf_kexec_setup()]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:04 -07:00
Oleg Nesterov
1b0f7ffd0e pids: kill signal_struct-> __pgrp/__session and friends
We are wasting 2 words in signal_struct without any reason to implement
task_pgrp_nr() and task_session_nr().

task_session_nr() has no callers since
2e2ba22ea4, we can remove it.

task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and
fs/coda.

This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills
__pgrp/__session and the related helpers.

The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense
anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <number6@the-village.bc.nu>		[tty parts]
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.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>
2009-04-02 19:05:02 -07:00
Oleg Nesterov
52ee2dfdd4 pids: refactor vnr/nr_ns helpers to make them safe
Inho, the safety rules for vnr/nr_ns helpers are horrible and buggy.

task_pid_nr_ns(task) needs rcu/tasklist depending on task == current.

As for "special" pids, vnr/nr_ns helpers always need rcu.  However, if
task != current, they are unsafe even under rcu lock, we can't trust
task->group_leader without the special checks.

And almost every helper has a callsite which needs a fix.

Also, it is a bit annoying that the implementations of, say,
task_pgrp_vnr() and task_pgrp_nr_ns() are not "symmetrical".

This patch introduces the new helper, __task_pid_nr_ns(), which is always
safe to use, and turns all other helpers into the trivial wrappers.

After this I'll send another patch which converts task_tgid_xxx() as well,
they're are a bit special.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.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>
2009-04-02 19:05:02 -07:00
Oleg Nesterov
2ae448efc8 pids: improve get_task_pid() to fix the unsafe sys_wait4()->task_pgrp()
sys_wait4() does get_pid(task_pgrp(current)), this is not safe.  We can
add rcu lock/unlock around, but we already have get_task_pid() which can
be improved to handle the special pids in more reliable manner.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.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>
2009-04-02 19:05:02 -07:00
Matthew Wilcox
8e654fba4a sysctl: fix suid_dumpable and lease-break-time sysctls
Arne de Bruijn points out that commit
76fdbb25f9 ("coredump masking: bound
suid_dumpable sysctl") mistakenly limits lease-break-time instead of
suid_dumpable.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Reported-by: Arne de Bruijn <kernelbt@arbruijn.dds.nl>
Cc: Kawai, Hidehiro <hidehiro.kawai.ez@hitachi.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:01 -07:00
Serge E. Hallyn
11dea19009 proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlers
As pointed out by Cedric Le Goater (in response to Alexey's original
comment wrt mqns), ipc_sysctl.c and utsname_sysctl.c are using
CONFIG_PROC_FS, not CONFIG_PROC_SYSCTL, to determine whether to define
the proc_handlers.  Change that.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:01 -07:00
Lai Jiangshan
2355b70fd5 workqueue: avoid recursion in run_workqueue()
1) lockdep will complain when run_workqueue() performs recursion.

2) The recursive implementation of run_workqueue() means that
   flush_workqueue() and its documentation are inconsistent.  This may
   hide deadlocks and other bugs.

3) The recursion in run_workqueue() will poison cwq->current_work, but
   flush_work() and __cancel_work_timer(), etcetera need a reliable
   cwq->current_work.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:00 -07:00
Oleg Nesterov
1ee1184485 ptrace_untrace: fix the SIGNAL_STOP_STOPPED check
This bug is ancient too. ptrace_untrace() must not resume the task
if the group stop in progress, we should set TASK_STOPPED instead.

Unfortunately, we still have problems here:

	- if the process/thread was traced, SIGNAL_STOP_STOPPED
	  does not necessary means this thread group is stopped.

	- ptrace breaks the bookkeeping of ->group_stop_count.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:00 -07:00
Oleg Nesterov
95a3540da9 ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic
Another ancient bug. Consider this trivial test-case,

	int main(void)
	{
		int pid = fork();

		if (pid) {
			ptrace(PTRACE_ATTACH, pid, NULL, NULL);
			wait(NULL);
			ptrace(PTRACE_DETACH, pid, NULL, NULL);
		} else {
			pause();
			printf("WE HAVE A KERNEL BUG!!!\n");
		}

		return 0;
	}

the child must not "escape" for sys_pause(), but it can and this was seen
in practice.

This is because ptrace_detach does:

	if (!child->exit_state)
		wake_up_process(child);

this wakeup can happen after this child has already restarted sys_pause(),
because it gets another wakeup from ptrace_untrace().

With or without this patch, perhaps sys_pause() needs a fix.  But this
wakeup also breaks the SIGNAL_STOP_STOPPED logic in ptrace_untrace().

Remove this wakeup.  The caller saw this task in TASK_TRACED state, and
unless it was SIGKILL'ed in between __ptrace_unlink()->ptrace_untrace()
should handle this case correctly.  If it was SIGKILL'ed, we don't need to
wakup the dying tracee too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:00 -07:00
Oleg Nesterov
5dfc80be73 forget_original_parent: do not abuse child->ptrace_entry
By discussion with Roland.

- Use ->sibling instead of ->ptrace_entry to chain the need to be
  release_task'd childs. Nobody else can use ->sibling, this task
  is EXIT_DEAD and nobody can find it on its own list.

- rename ptrace_dead to dead_childs.

- Now that we don't have the "parallel" untrace code, change back
  reparent_thread() to return void, pass dead_childs as an argument.

Actually, I don't understand why do we notify /sbin/init when we
reparent a zombie, probably it is better to reap it unconditionally.

[akpm@linux-foundation.org: s/childs/children/]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Metzger, Markus T" <markus.t.metzger@intel.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>
2009-04-02 19:05:00 -07:00
Oleg Nesterov
39c626ae47 forget_original_parent: split out the un-ptrace part
By discussion with Roland.

- Rename ptrace_exit() to exit_ptrace(), and change it to do all the
  necessary work with ->ptraced list by its own.

- Move this code from exit.c to ptrace.c

- Update the comment in ptrace_detach() to explain the rechecking of
  the child->ptrace.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Metzger, Markus T" <markus.t.metzger@intel.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>
2009-04-02 19:05:00 -07:00
Oleg Nesterov
7f5d3652d4 reparent_thread: fix a zombie leak if /sbin/init ignores SIGCHLD
If /sbin/init ignores SIGCHLD and we re-parent a zombie, it is leaked.
reparent_thread() does do_notify_parent() which sets ->exit_signal = -1 in
this case.  This means that nobody except us can reap it, the detached
task is not visible to do_wait().

Change reparent_thread() to return a boolean (like __pthread_detach) to
indicate that the thread is dead and must be released.  Also change
forget_original_parent() to add the child to ptrace_dead list in this
case.

The naming becomes insane, the next patch does the cleanup.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
b1442b055c reparent_thread: fix the "is it traced" check
reparent_thread() uses ptrace_reparented() to check whether this thread is
ptraced, in that case we should not notify the new parent.

But ptrace_reparented() is not exactly correct when the reparented thread
is traced by /sbin/init, because forget_original_parent() has already
changed ->real_parent.

Currently, the only problem is the false notification.  But with the next
patch the kernel crash in this (yes, pathological) case.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
0a967a044a reparent_thread: don't call kill_orphaned_pgrp() if task_detached()
If task_detached(p) == T, then either

  a) p is not the main thread, we will find the group leader on the
     ->children list.

or

  b) p is the group leader but its ->exit_state = EXIT_DEAD.  This
     can only happen when the last sub-thread has died, but in that case
     that thread has already called kill_orphaned_pgrp() from
     exit_notify().

In both cases kill_orphaned_pgrp() looks bogus.

Move the task_detached() check up and simplify the code, this is also
right from the "common sense" pov: we should do nothing with the detached
childs, except move them to the new parent's ->children list.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
4576145c1e ptrace: fix possible zombie leak on PTRACE_DETACH
When ptrace_detach() takes tasklist, the tracee can be SIGKILL'ed.  If it
has already passed exit_notify() we can leak a zombie, because a) ptracing
disables the auto-reaping logic, and b) ->real_parent was not notified
about the child's death.

ptrace_detach() should follow the ptrace_exit's logic, change the code
accordingly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Tested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
b1b4c6799f ptrace: reintroduce __ptrace_detach() as a callee of ptrace_exit()
No functional changes, preparation for the next patch.

Move the "should we release this child" logic into the separate handler,
__ptrace_detach().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
6d69cb87f0 ptrace: simplify ptrace_exit()->ignoring_children() path
ignoring_children() takes parent->sighand->siglock and checks
k_sigaction[SIGCHLD] atomically.  But this buys nothing, we can't get the
"really" wrong result even if we race with sigaction(SIGCHLD).  If we read
the "stale" sa_handler/sa_flags we can pretend it was changed right after
the check.

Remove spin_lock(->siglock), and kill "int ign" which caches the result of
ignoring_children() which becomes rather trivial.

Perhaps it makes sense to export this helper, do_notify_parent() can use
it too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Oleg Nesterov
95c3eb76dc ptrace: kill __ptrace_detach(), fix ->exit_state check
Move the code from __ptrace_detach() to its single caller and kill this
helper.

Also, fix the ->exit_state check, we shouldn't wake up EXIT_DEAD tasks.
Actually, I think task_is_stopped_or_traced() makes more sense, but this
needs another patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:59 -07:00
Sukadev Bhattiprolu
6588c1e3ff signals: SI_USER: Masquerade si_pid when crossing pid ns boundary
When sending a signal to a descendant namespace, set ->si_pid to 0 since
the sender does not have a pid in the receiver's namespace.

Note:
	- If rt_sigqueueinfo() sets si_code to SI_USER when sending a
	  signal across a pid namespace boundary, the value in ->si_pid
	  will be cleared to 0.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Sukadev Bhattiprolu
b3bfa0cba8 signals: protect cinit from blocked fatal signals
Normally SIG_DFL signals to global and container-init are dropped early.
But if a signal is blocked when it is posted, we cannot drop the signal
since the receiver may install a handler before unblocking the signal.
Once this signal is queued however, the receiver container-init has no way
of knowing if the signal was sent from an ancestor or descendant
namespace.  This patch ensures that contianer-init drops all SIG_DFL
signals in get_signal_to_deliver() except SIGKILL/SIGSTOP.

If SIGSTOP/SIGKILL originate from a descendant of container-init they are
never queued (i.e dropped in sig_ignored() in an earler patch).

If SIGSTOP/SIGKILL originate from parent namespace, the signal is queued
and container-init processes the signal.

IOW, if get_signal_to_deliver() sees a sig_kernel_only() signal for global
or container-init, the signal must have been generated internally or must
have come from an ancestor ns and we process the signal.

Further, the signal_group_exit() check was needed to cover the case of a
multi-threaded init sending SIGKILL to other threads when doing an exit()
or exec().  But since the new sig_kernel_only() check covers the SIGKILL,
the signal_group_exit() check is no longer needed and can be removed.

Finally, now that we have all pieces in place, set SIGNAL_UNKILLABLE for
container-inits.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Sukadev Bhattiprolu
e4da026f98 signals: zap_pid_ns_process() should use force_sig()
send_signal() assumes that signals with SEND_SIG_PRIV are generated from
within the same namespace.  So any nested container-init processes become
immune to the SIGKILL generated by kill_proc_info() in
zap_pid_ns_processes().

Use force_sig() in zap_pid_ns_processes() instead - force_sig() clears the
SIGNAL_UNKILLABLE flag ensuring the signal is processed by
container-inits.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Sukadev Bhattiprolu
921cf9f630 signals: protect cinit from unblocked SIG_DFL signals
Drop early any SIG_DFL or SIG_IGN signals to container-init from within
the same container.  But queue SIGSTOP and SIGKILL to the container-init
if they are from an ancestor container.

Blocked, fatal signals (i.e when SIG_DFL is to terminate) from within the
container can still terminate the container-init.  That will be addressed
in the next patch.

Note:	To be bisect-safe, SIGNAL_UNKILLABLE will be set for container-inits
   	in a follow-on patch. Until then, this patch is just a preparatory
	step.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Sukadev Bhattiprolu
7978b567d3 signals: add from_ancestor_ns parameter to send_signal()
send_signal() (or its helper) needs to determine the pid namespace of the
sender.  But a signal sent via kill_pid_info_as_uid() comes from within
the kernel and send_signal() does not need to determine the pid namespace
of the sender.  So define a helper for send_signal() which takes an
additional parameter, 'from_ancestor_ns' and have kill_pid_info_as_uid()
use that helper directly.

The 'from_ancestor_ns' parameter will be used in a follow-on patch.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Oleg Nesterov
f008faff0e signals: protect init from unwanted signals more
(This is a modified version of the patch submitted by Oleg Nesterov
http://lkml.org/lkml/2008/11/18/249 and tries to address comments that
came up in that discussion)

init ignores the SIG_DFL signals but we queue them anyway, including
SIGKILL.  This is mostly OK, the signal will be dropped silently when
dequeued, but the pending SIGKILL has 2 bad implications:

        - it implies fatal_signal_pending(), so we confuse things
          like wait_for_completion_killable/lock_page_killable.

        - for the sub-namespace inits, the pending SIGKILL can
          mask (legacy_queue) the subsequent SIGKILL from the
          parent namespace which must kill cinit reliably.
          (preparation, cinits don't have SIGNAL_UNKILLABLE yet)

The patch can't help when init is ptraced, but ptracing of init is not
"safe" anyway.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:58 -07:00
Oleg Nesterov
43918f2bf4 signals: remove 'handler' parameter to tracehook functions
Container-init must behave like global-init to processes within the
container and hence it must be immune to unhandled fatal signals from
within the container (i.e SIG_DFL signals that terminate the process).

But the same container-init must behave like a normal process to processes
in ancestor namespaces and so if it receives the same fatal signal from a
process in ancestor namespace, the signal must be processed.

Implementing these semantics requires that send_signal() determine pid
namespace of the sender but since signals can originate from workqueues/
interrupt-handlers, determining pid namespace of sender may not always be
possible or safe.

This patchset implements the design/simplified semantics suggested by
Oleg Nesterov.  The simplified semantics for container-init are:

	- container-init must never be terminated by a signal from a
	  descendant process.

	- container-init must never be immune to SIGKILL from an ancestor
	  namespace (so a process in parent namespace must always be able
	  to terminate a descendant container).

	- container-init may be immune to unhandled fatal signals (like
	  SIGUSR1) even if they are from ancestor namespace. SIGKILL/SIGSTOP
	  are the only reliable signals to a container-init from ancestor
	  namespace.

This patch:

Based on an earlier patch submitted by Oleg Nesterov and comments from
Roland McGrath (http://lkml.org/lkml/2008/11/19/258).

The handler parameter is currently unused in the tracehook functions.
Besides, the tracehook functions are called with siglock held, so the
functions can check the handler if they later need to.

Removing the parameter simiplifies changes to sig_ignored() in a follow-on
patch.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>
2009-04-02 19:04:58 -07:00
Oleg Nesterov
90bc8d8b1a do_wait: fix waiting for the group stop with the dead leader
do_wait(WSTOPPED) assumes that p->state must be == TASK_STOPPED, this is
not true if the leader is already dead.  Check SIGNAL_STOP_STOPPED instead
and use signal->group_exit_code.

Trivial test-case:

	void *tfunc(void *arg)
	{
		pause();
		return NULL;
	}

	int main(void)
	{
		pthread_t thr;
		pthread_create(&thr, NULL, tfunc, NULL);
		pthread_exit(NULL);
		return 0;
	}

It doesn't react to ^Z (and then to ^C or ^\). The task is stopped, but
bash can't see this.

The bug is very old, and it was reported multiple times. This patch was sent
more than a year ago (http://marc.info/?t=119713920000003) but it was ignored.

This change also fixes other oddities (but not all) in this area.  For
example, before this patch:

	$ sleep 100
	^Z
	[1]+  Stopped                 sleep 100
	$ strace -p `pidof sleep`
	Process 11442 attached - interrupt to quit

strace hangs in do_wait(), because ->exit_code was already consumed by
bash.  After this patch, strace happily proceeds:

	--- SIGTSTP (Stopped) @ 0 (0) ---
	restart_syscall(<... resuming interrupted call ...>

To me, this looks much more "natural" and correct.

Another example.  Let's suppose we have the main thread M and sub-thread
T, the process is stopped, and its parent did wait(WSTOPPED).  Now we can
ptrace T but not M.  This looks at least strange to me.

Imho, do_wait() should not confuse the per-thread ptrace stops with the
per-process job control stops.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Kaz Kylheku <kkylheku@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:57 -07:00
David Rientjes
6d7b2f5f9e cpusets: prevent PF_THREAD_BOUND tasks from attaching to non-root cpusets
Kthreads that have the PF_THREAD_BOUND bit set in their flags are bound to a
specific cpu.  Thus, their set of allowed cpus shall not change.

This patch prevents such threads from attaching to non-root cpusets.  They do
not have mempolicies that restrict them to a subset of system nodes and, since
their cpumask may never change, they cannot use any of the features of
cpusets.

The tasks will forever be a member of the root cpuset and will be returned
when listing the tasks attached to that cpuset.

Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:57 -07:00
Paul Menage
db7f47cf48 cpusets: allow cpusets to be configured/built on non-SMP systems
Allow cpusets to be configured/built on non-SMP systems

Currently it's impossible to build cpusets under UML on x86-64, since
cpusets depends on SMP and x86-64 UML doesn't support SMP.

There's code in cpusets that doesn't depend on SMP.  This patch surrounds
the minimum amount of cpusets code with #ifdef CONFIG_SMP in order to
allow cpusets to build/run on UP systems (for testing purposes under UML).

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Paul Menage <menage@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:57 -07:00