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3911 commits

Author SHA1 Message Date
Oleg Nesterov
6ca25b5513 kill_pid_info: don't take now unneeded tasklist_lock
Previously handle_stop_signal(SIGCONT) could drop ->siglock.  That is why
kill_pid_info(SIGCONT) takes tasklist_lock to make sure the target task can't
go away after unlock.  Not needed now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
e442055193 signals: re-assign CLD_CONTINUED notification from the sender to reciever
Based on discussion with Jiri and Roland.

In short: currently handle_stop_signal(SIGCONT, p) sends the notification to
p->parent, with this patch p itself notifies its parent when it becomes
running.

handle_stop_signal(SIGCONT) has to drop ->siglock temporary in order to notify
the parent with do_notify_parent_cldstop().  This leads to multiple problems:

	- as Jiri Kosina pointed out, the stopped task can resume without
	  actually seeing SIGCONT which may have a handler.

	- we race with another sig_kernel_stop() signal which may come in
	  that window.

	- we race with sig_fatal() signals which may set SIGNAL_GROUP_EXIT
	  in that window.

	- we can't avoid taking tasklist_lock() while sending SIGCONT.

With this patch handle_stop_signal() just sets the new SIGNAL_CLD_CONTINUED
flag in p->signal->flags and returns.  The notification is sent by the first
task which returns from finish_stop() (there should be at least one) or any
other signalled thread from get_signal_to_deliver().

This is a user-visible change.  Say, currently kill(SIGCONT, stopped_child)
can't return without seeing SIGCHLD, with this patch SIGCHLD can be delayed
unpredictably.  Another difference is that if the child is ptraced by another
process, CLD_CONTINUED may be delivered to ->real_parent after ptrace_detach()
while currently it always goes to the tracer which doesn't actually need this
notification.  Hopefully not a problem.

The patch asks for the futher obvious cleanups, I'll send them separately.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
3b5e9e53c6 signals: cleanup security_task_kill() usage/implementation
Every implementation of ->task_kill() does nothing when the signal comes from
the kernel.  This is correct, but means that check_kill_permission() should
call security_task_kill() only for SI_FROMUSER() case, and we can remove the
same check from ->task_kill() implementations.

(sadly, check_kill_permission() is the last user of signal->session/__session
 but we can't s/task_session_nr/task_session/ here).

NOTE: Eric W.  Biederman pointed out cap_task_kill() should die, and I think
he is very right.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: David Quigley <dpquigl@tycho.nsa.gov>
Cc: Eric Paris <eparis@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
9e3bd6c3fb signals: consolidate send_sigqueue and send_group_sigqueue
Both functions do the same thing after proper locking, but with
different sigpending structs, so move the common code into a helper.

After this we have 4 places that look very similar: send_sigqueue: calls
do_send_sigqueue and signal_wakeup send_group_sigqueue: calls
do_send_sigqueue and __group_complete_signal __group_send_sig_info:
calls send_signal and __group_complete_signal specific_send_sig_info:
calls send_signal and signal_wakeup

Besides, send_signal performs actions similar to do_send_sigqueue's
and __group_complete_signal - to signal_wakeup.

It looks like they can be consolidated gracefully.

Oleg said:

  Personally, I think this change is very good.  But send_sigqueue() and
  send_group_sigqueue() have a very subtle difference which I was never able
  to understand.

  Let's suppose that sigqueue is already queued, and the signal is ignored
  (the latter means we should re-schedule cpu timer or handle overrruns).  In
  that case send_sigqueue() returns 0, but send_group_sigqueue() returns 1.

  I think this is not the problem (in fact, I think this patch makes the
  behaviour more correct), but I hope Thomas can take a look and confirm.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
c5363d0363 signals: clean dequeue_signal from excess checks and assignments
The signr variable may be declared without initialization - it is set ro the
return value from __dequeue_signal() right at the function beginning.

Besides, after recalc_sigpending() two checks for signr to be not 0 may be
merged into one.  Both if-s become easier to read.

Thanks to Oleg for pointing out mistakes in the first version of this patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
93585eeaf3 signals: consolidate checks for whether or not to ignore a signal
Both sig_ignored() and do_sigaction() check for signr to be explicitly or
implicitly ignored.  Introduce a helper for them.

This patch is aimed to help handling signals by pid namespace's init, and was
derived from one of Oleg's patches
https://lists.linux-foundation.org/pipermail/containers/2007-December/009308.html
so, if he doesn't mind, he should be considered as an author.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
d6cf723a14 k_getrusage: don't take rcu_read_lock()
Just a trivial example, more to come.

k_getrusage() holds rcu_read_lock() because it was previously required by
lock_task_sighand().  Unneeded now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Paul E. McKenney" <paulmck@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>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
1406f2d321 lock_task_sighand: add rcu lock/unlock
Most of the callers of lock_task_sighand() doesn't actually need rcu_lock().
lock_task_sighand() needs it only to safely play with tsk->sighand, it can
take the lock itself.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Paul E. McKenney" <paulmck@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>
2008-04-30 08:29:33 -07:00
Oleg Nesterov
bfc4b0890a signals: do_group_exit(): use signal_group_exit() more consistently
do_group_exit() checks SIGNAL_GROUP_EXIT to avoid taking sighand->siglock.
Since ed5d2cac11 exec() doesn't set this
flag, we should use signal_group_exit().

This is not needed for correctness, but can speedup the multithreaded exec
and makes the code more consistent.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Oleg Nesterov
573cf9ad72 signals: do_signal_stop(): use signal_group_exit()
do_signal_stop() needs signal_group_exit() but checks sig->group_exit_task.
 This (optimization) is correct, SIGNAL_STOP_DEQUEUED and SIGNAL_GROUP_EXIT
are mutually exclusive, but looks confusing.  Use signal_group_exit(), this
is not fastpath, the code clarity is more important.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
2acb024d55 signals: consolidate checking for ignored/legacy signals
Two callers for send_signal() - the specific_send_sig_info and the
__group_send_sig_info - both check for sig to be ignored or already queued.

Move these checks into send_signal() and make it return 1 to indicate that the
signal is dropped, but there's no error in this.

Besides, merge comments and spell-check them.

[oleg@tv-sign.ru: simplifications]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
af7fff9c13 signals: turn LEGACY_QUEUE macro into static inline function
This makes the code more readable, due to less brackets and small letters in
name.

I also move it above the send_signal() as a preparation for the 3rd patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
e1401c6bbb signals: remove unused variable from send_signal()
This function doesn't change the ret's value and thus always returns 0, with a
single exception of returning -EAGAIN explicitly.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Linus Torvalds
9781db7b34 Merge branch 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] new predicate - AUDIT_FILETYPE
  [patch 2/2] Use find_task_by_vpid in audit code
  [patch 1/2] audit: let userspace fully control TTY input auditing
  [PATCH 2/2] audit: fix sparse shadowed variable warnings
  [PATCH 1/2] audit: move extern declarations to audit.h
  Audit: MAINTAINERS update
  Audit: increase the maximum length of the key field
  Audit: standardize string audit interfaces
  Audit: stop deadlock from signals under load
  Audit: save audit_backlog_limit audit messages in case auditd comes back
  Audit: collect sessionid in netlink messages
  Audit: end printk with newline
2008-04-29 11:41:22 -07:00
Linus Torvalds
bd5d435a96 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: Skip I/O merges when disabled
  block: add large command support
  block: replace sizeof(rq->cmd) with BLK_MAX_CDB
  ide: use blk_rq_init() to initialize the request
  block: use blk_rq_init() to initialize the request
  block: rename and export rq_init()
  block: no need to initialize rq->cmd with blk_get_request
  block: no need to initialize rq->cmd in prepare_flush_fn hook
  block/blk-barrier.c:blk_ordered_cur_seq() mustn't be inline
  block/elevator.c:elv_rq_merge_ok() mustn't be inline
  block: make queue flags non-atomic
  block: add dma alignment and padding support to blk_rq_map_kern
  unexport blk_max_pfn
  ps3disk: Remove superfluous cast
  block: make rq_init() do a full memset()
  relay: fix splice problem
2008-04-29 08:18:03 -07:00
Christoph Lameter
37487a5652 Add kbuild.h that contains common definitions for kbuild users
The same definitions are used for the bounds logic and the asm-offsets.h
generation by kbuild.  Put them into include/linux/kbuild.h file.

Also add a new feature

	COMMENT("text")

which can be used to insert lines of ocmments into asm-offsets.h and
bounds.h.

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jay Estabrook <jay.estabrook@hp.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
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: Paul Mundt <lethal@linux-sh.org>
Cc: Miles Bader <miles@gnu.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:29 -07:00
Masami Hiramatsu
68ab3d883a relayfs: support larger relay buffer
Use vmalloc() and memset() instead of kcalloc() to allocate a page* array when
the array size is bigger than one page.  This enables relayfs to support
bigger relay buffers than 64MB on 4k-page system, 512MB on 16k-page system.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: David Wilder <dwilder@us.ibm.com>
Reviewed-by: Tom Zanussi <zanussi@comcast.net>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:28 -07:00
Hirofumi Nakagawa
801678c5a3 Remove duplicated unlikely() in IS_ERR()
Some drivers have duplicated unlikely() macros.  IS_ERR() already has
unlikely() in itself.

This patch cleans up such pointless code.

Signed-off-by: Hirofumi Nakagawa <hnakagawa@miraclelinux.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jeff@garzik.org>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
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>
2008-04-29 08:06:25 -07:00
Pavel Emelyanov
d7321cd624 sysctl: add the ->permissions callback on the ctl_table_root
When reading from/writing to some table, a root, which this table came from,
may affect this table's permissions, depending on who is working with the
table.

The core hunk is at the bottom of this patch.  All the rest is just pushing
the ctl_table_root argument up to the sysctl_perm() function.

This will be mostly (only?) used in the net sysctls.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:23 -07:00
Pavel Emelyanov
2c4c7155f2 sysctl: clean from unneeded extern and forward declarations
The do_sysctl_strategy isn't used outside kernel/sysctl.c, so this can be
static and without a prototype in header.

Besides, move this one and parse_table() above their callers and drop the
forward declarations of the latter call.

One more "besides" - fix two checkpatch warnings: space before a ( and an
extra space at the end of a line.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Denis V. Lunev <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:23 -07:00
Holger Schurig
88f458e4b9 sysctl: allow embedded targets to disable sysctl_check.c
Disable sysctl_check.c for embedded targets. This saves about about 11 kB
in .text and another 11 kB in .data on a PXA255 embedded platform.

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
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>
2008-04-29 08:06:22 -07:00
Denis V. Lunev
c33fff0afb kernel: use non-racy method for proc entries creation
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:22 -07:00
Alexey Dobriyan
c74c120a21 proc: remove proc_root from drivers
Remove proc_root export.  Creation and removal works well if parent PDE is
supplied as NULL -- it worked always that way.

So, one useless export removed and consistency added, some drivers created
PDEs with &proc_root as parent but removed them as NULL and so on.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:18 -07:00
Matt Helsley
925d1c401f procfs task exe symlink
The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA.  Then the path to the file is reconstructed and
reported as the result.

Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems.  Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.

That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs.  So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped.  This avoids pinning the mounted filesystem.

[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
David Howells
0b77f5bfb4 keys: make the keyring quotas controllable through /proc/sys
Make the keyring quotas controllable through /proc/sys files:

 (*) /proc/sys/kernel/keys/root_maxkeys
     /proc/sys/kernel/keys/root_maxbytes

     Maximum number of keys that root may have and the maximum total number of
     bytes of data that root may have stored in those keys.

 (*) /proc/sys/kernel/keys/maxkeys
     /proc/sys/kernel/keys/maxbytes

     Maximum number of keys that each non-root user may have and the maximum
     total number of bytes of data that each of those users may have stored in
     their keys.

Also increase the quotas as a number of people have been complaining that it's
not big enough.  I'm not sure that it's big enough now either, but on the
other hand, it can now be set in /etc/sysctl.conf.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
David Howells
69664cf16a keys: don't generate user and user session keyrings unless they're accessed
Don't generate the per-UID user and user session keyrings unless they're
explicitly accessed.  This solves a problem during a login process whereby
set*uid() is called before the SELinux PAM module, resulting in the per-UID
keyrings having the wrong security labels.

This also cures the problem of multiple per-UID keyrings sometimes appearing
due to PAM modules (including pam_keyinit) setuiding and causing user_structs
to come into and go out of existence whilst the session keyring pins the user
keyring.  This is achieved by first searching for extant per-UID keyrings
before inventing new ones.

The serial bound argument is also dropped from find_keyring_by_name() as it's
not currently made use of (setting it to 0 disables the feature).

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
Serge E. Hallyn
02fdb36ae7 ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC)
CLONE_NEWIPC|CLONE_SYSVSEM interaction isn't handled properly.  This can cause
a kernel memory corruption.  CLONE_NEWIPC must detach from the existing undo
lists.

Fix, part 3: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC).

With unshare, specifying CLONE_SYSVSEM means unshare the sysvsem.  So it seems
reasonable that CLONE_NEWIPC without CLONE_SYSVSEM would just imply
CLONE_SYSVSEM.

However with clone, specifying CLONE_SYSVSEM means *share* the sysvsem.  So
calling clone(CLONE_SYSVSEM|CLONE_NEWIPC) is explicitly asking for something
we can't allow.  So return -EINVAL in that case.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:14 -07:00
Manfred Spraul
6013f67fc1 ipc: sysvsem: force unshare(CLONE_SYSVSEM) when CLONE_NEWIPC
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption.  CLONE_NEWIPC must detach from the existing
undo lists.

Fix, part 2: perform an implicit CLONE_SYSVSEM in CLONE_NEWIPC.  CLONE_NEWIPC
creates a new IPC namespace, the task cannot access the existing semaphore
arrays after the unshare syscall.  Thus the task can/must detach from the
existing undo list entries, too.

This fixes the kernel corruption, because it makes it impossible that
undo records from two different namespaces are in sysvsem.undo_list.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:14 -07:00
Manfred Spraul
9edff4ab1f ipc: sysvsem: implement sys_unshare(CLONE_SYSVSEM)
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption.  CLONE_NEWIPC must detach from the existing
undo lists.

Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM)

The original reason to not support it was the potential (inevitable?)
confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the
inverse meaning of clone(CLONE_SYSVSEM).

Our two most reasonable options then appear to be (1) fully support
CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM,
but always do it anyway on unshare(CLONE_SYSVSEM).  This patch does
(1).

Changelog:
	Apr 16: SEH: switch to Manfred's alternative patch which
		removes the unshare_semundo() function which
		always refused CLONE_SYSVSEM.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:14 -07:00
Nadia Derbey
6546bc4279 ipc: re-enable msgmni automatic recomputing msgmni if set to negative
The enhancement as asked for by Yasunori: if msgmni is set to a negative
value, register it back into the ipcns notifier chain.

A new interface has been added to the notification mechanism:
notifier_chain_cond_register() registers a notifier block only if not already
registered.  With that new interface we avoid taking care of the states
changes in procfs.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:13 -07:00
Oleg Nesterov
d2ba7e2ae2 simplify cpu_hotplug_begin()/put_online_cpus()
cpu_hotplug_begin() must be always called under cpu_add_remove_lock, this
means that only one process can be cpu_hotplug.active_writer.  So we don't
need the cpu_hotplug.writer_queue, we can wake up the ->active_writer
directly.

Also, fix the comment.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Acked-by: Gautham R Shenoy <ego@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Oleg Nesterov
1e35eaa2d8 cleanup_workqueue_thread: remove the unneeded "cpu" parameter
cleanup_workqueue_thread() doesn't need the second argument, remove it.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Oleg Nesterov
00dfcaf748 workqueues: shrink cpu_populated_map when CPU dies
When cpu_populated_map was introduced, it was supposed that cwq->thread can
survive after CPU_DEAD, that is why we never shrink cpu_populated_map.

This is not very nice, we can safely remove the already dead CPU from the map.
 The only required change is that destroy_workqueue() must hold the hotplug
lock until it destroys all cwq->thread's, to protect the cpu_populated_map.
We could make the local copy of cpu mask and drop the lock, but
sizeof(cpumask_t) may be very large.

Also, fix the comment near queue_work().  Unless _cpu_down() happens we do
guarantee the cpu-affinity of the work_struct, and we have users which rely on
this.

[akpm@linux-foundation.org: repair comment]
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Paul Menage
786083667e Cpuset hardwall flag: add a mem_hardwall flag to cpusets
This flag provides the hardwalling properties of mem_exclusive, without
enforcing the exclusivity.  Either mem_hardwall or mem_exclusive is sufficient
to prevent GFP_KERNEL allocations from passing outside the cpuset's assigned
nodes.

Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Paul Menage
addf2c739d Cpuset hardwall flag: switch cpusets to use the bulk cgroup_add_files() API
Currently the cpusets mem_exclusive flag is overloaded to mean both
"no-overlapping" and "no GFP_KERNEL allocations outside this cpuset".

These patches add a new mem_hardwall flag with just the allocation restriction
part of the mem_exclusive semantics, without breaking backwards-compatibility
for those who continue to use just mem_exclusive.  Additionally, the cgroup
control file registration for cpusets is cleaned up to reduce boilerplate.

This patch:

This change tidies up the cpusets control file definitions, and reduces the
amount of boilerplate required to add/change control files in the future.

Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Adrian Bunk
9e0c914cab kernel/cpuset.c: make 3 functions static
Make the following needlessly global functions static:

- cpuset_test_cpumask()
- cpuset_change_cpumask()
- cpuset_do_move_task()

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:11 -07:00
Pavel Emelyanov
c84872e168 memcgroup: add the max_usage member on the res_counter
This field is the maximal value of the usage one since the counter creation
(or since the latest reset).

To reset this to the usage value simply write anything to the appropriate
cgroup file.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Balbir Singh
cf475ad28a cgroups: add an owner to the mm_struct
Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>,
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Serge E. Hallyn
29486df325 cgroups: introduce cft->read_seq()
Introduce a read_seq() helper in cftype, which uses seq_file to print out
lists.  Use it in the devices cgroup.  Also split devices.allow into two
files, so now devices.deny and devices.allow are the ones to use to manipulate
the whitelist, while devices.list outputs the cgroup's current whitelist.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Li Zefan
28fd5dfc12 cgroups: remove the css_set linked-list
Now we can run through the hash table instead of running through the
linked-list.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Li Zefan
e8d55fdeb8 cgroups: simplify init_subsys()
We are at system boot and there is only 1 cgroup group (i,e, init_css_set), so
we don't need to run through the css_set linked list.  Neither do we need to
run through the task list, since no processes have been created yet.

Also referring to a comment in cgroup.h:

struct css_set
{
	...
	/*
	 * Set of subsystem states, one for each subsystem. This array
	 * is immutable after creation apart from the init_css_set
	 * during subsystem registration (at boot time).
	 */
	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
}

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:10 -07:00
Li Zefan
472b1053f3 cgroups: use a hash table for css_set finding
When we attach a process to a different cgroup, the css_set linked-list will
be run through to find a suitable existing css_set to use.  This patch
implements a hash table for better performance.

The following benchmarks have been tested:

For N in 1, 5, 10, 50, 100, 500, 1000, create N cgroups with one sleeping
task in each, and then move an additional task through each cgroup in
turn.

Here is a test result:

N	Loop	orig - Time(s)	hash - Time(s)
----------------------------------------------
1	10000	1.201231728	1.196311177
5	2000	1.065743872	1.040566424
10	1000	0.991054735	0.986876440
50	200	0.976554203	0.969608733
100	100	0.998504680	0.969218270
500	20	1.157347764	0.962602963
1000	10	1.619521852	1.085140172

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Pavel Emelyanov
d447ea2f30 cgroups: add the trigger callback to struct cftype
Trigger callback can be used to receive a kick-up from the user space.  The
string written is ignored.

The cftype->private is used for multiplexing events.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Paul Menage <menage@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Li Zefan
46ae220bea cgroup: switch to proc_create()
There is a race between create_proc_entry() and the assignment of file ops.
proc_create() is invented to fix it.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.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>
2008-04-29 08:06:09 -07:00
Li Zefan
06a119204d cgroup: annotate cgroup_init_subsys with __init
It is called by cgroup_init() and cgroup_init_early() only, which are
annotated with __init.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.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>
2008-04-29 08:06:09 -07:00
Paul Menage
06ecb27cfb CGroups _s64 files: use read_s64/write_s64 in CFS cgroup for rt_runtime file
This removes some filesystem boilerplate from the CFS cgroup subsystem.

Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Paul Menage
e73d2c61d1 CGroups _s64 files: add cgroups read_s64/write_s64 file methods
These patches add cgroups read_s64 and write_s64 control file methods (the
signed equivalent of read_u64/write_u64) and use them to implement the
cpu.rt_runtime_us control file in the CFS cgroup subsystem.

This patch:

These are the signed equivalents of the read_u64/write_u64 methods

Signed-off-by: Paul Menage <menage@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Paul Menage
3116f0e3df CGroup API files: move "releasable" to cgroup_debug subsystem
The "releasable" control file provided by the cgroup framework exports the
state of a per-cgroup flag that's related to the notify-on-release feature.
This isn't really generally useful, unless you're trying to debug this
particular feature of cgroups.

This patch moves the "releasable" file to the cgroup_debug subsystem.

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Paul Menage
9179656961 CGroup API files: add cgroup map data type
Adds a new type of supported control file representation, a map from strings
to u64 values.

Each map entry is printed as a line in a similar format to /proc/vmstat, i.e.
"$key $value\n"

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage
700fe1ab99 CGroup API files: update cpusets to use cgroup structured file API
Many of the cpusets control files are simple integer values, which don't
require the overhead of memory allocations for reads and writes.

Move the handlers for these control files into cpuset_read_u64() and
cpuset_write_u64().

[akpm@linux-foundation.org: ad dmissing `break']
Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage
b7269dfc82 CGroup API files: strip all trailing whitespace in cgroup_write_u64
This removes the need for people to remember to pass the -n flag to echo when
writing values to cgroup control files.

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage
2c7eabf376 CGroup API files: add res_counter_read_u64()
Adds a function for returning the value of a resource counter member, in a
form suitable for use in a cgroup read_u64 control file method.

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:08 -07:00
Paul Menage
f4c753b7ea CGroup API files: rename read/write_uint methods to read_write_u64
Several people have justifiably complained that the "_uint" suffix is
inappropriate for functions that handle u64 values, so this patch just renames
all these functions and their users to have the suffic _u64.

[peterz@infradead.org: build fix]
Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: 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>
2008-04-29 08:06:07 -07:00
Adrian Bunk
3ff31d0cca cgroups: kernel/ns_cgroup.c should #include <linux/nsproxy.h>
Every file should include the headers containing the externs its global
functions (in this case for ns_cgroup_clone()).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:07 -07:00
Paul Jackson
4fe91d518e cgroup: fix sparse warning of shadow symbol in cgroup.c
Fix a code warning: symbol 'p' shadows an earlier one

This is a reincarnation of Harvey Harrison's patch:
	cpuset: sparse warnings in cpuset.c

Independently, Cliff Wickman moved the affected code,
from kernel/cpuset.c to kernel/cgroup.c, in his patch:
	cpusets: update_cpumask revision

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Cliff Wickman <cpw@sgi.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>
2008-04-29 08:06:07 -07:00
Adrian Bunk
3df91fe30a make cgroup_enable_task_cg_lists() static
Make the needlessly global cgroup_enable_task_cg_lists() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: David Rientjes <rientjes@google.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>
2008-04-29 08:06:07 -07:00
Michael Halcrow
6a3fd92e73 eCryptfs: make key module subsystem respect namespaces
Make eCryptfs key module subsystem respect namespaces.

Since I will be removing the netlink interface in a future patch, I just made
changes to the netlink.c code so that it will not break the build.  With my
recent patches, the kernel module currently defaults to the device handle
interface rather than the netlink interface.

[akpm@linux-foundation.org: export free_user_ns()]
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:07 -07:00
Dave Young
5f97a5a879 isolate ratelimit from printk.c for other use
Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file.  For some
serious complaining of kernel, we need repeat the warnings, so here I isolate
the ratelimit part of printk.c to a standalone file.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:06 -07:00
Robert P. J. Day
1aeb272cf0 kernel: explicitly include required header files under kernel/
Following an experimental deletion of the unnecessary directive

 #include <linux/slab.h>

from the header file <linux/percpu.h>, these files under kernel/ were exposed
as needing to include one of <linux/slab.h> or <linux/gfp.h>, so explicit
includes were added where necessary.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:04 -07:00
Dmitry Adamushko
cbd9b67bd3 kthread: call wake_up_process() without the lock being held
From the POV of synchronization, there should be no need to call
wake_up_process() with the 'kthread_create_lock' being held.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:04 -07:00
Sam Ravnborg
f7b16c108f cpu: fix section mismatch warning in reference to register_cpu_notifier
Fix following warnings:
WARNING: vmlinux.o(.text+0xc60): Section mismatch in reference from the function kvm_init() to the function .cpuinit.text:register_cpu_notifier()
WARNING: vmlinux.o(.text+0x33869a): Section mismatch in reference from the function xfs_icsb_init_counters() to the function .cpuinit.text:register_cpu_notifier()
WARNING: vmlinux.o(.text+0x5556a1): Section mismatch in reference from the function acpi_processor_install_hotplug_notify() to the function .cpuinit.text:register_cpu_notifier()
WARNING: vmlinux.o(.text+0xfe6b28): Section mismatch in reference from the function cpufreq_register_driver() to the function .cpuinit.text:register_cpu_notifier()

register_cpu_notifier() are only really defined when HOTPLUG_CPU is enabled.
So references to the function are OK.

Annotate it with __ref so we do not get warnings from callers and do not get
warnings for the functions/data used by register_cpu_notifier().

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:00 -07:00
Sam Ravnborg
514a20a5da cpu: fix section mismatch warnings in *cpu_down
Fix following warnings:
WARNING: vmlinux.o(.text+0x75c8d): Section mismatch in reference from the function take_cpu_down() to the variable .cpuinit.data:cpu_chain
WARNING: vmlinux.o(.text+0x75d2a): Section mismatch in reference from the function _cpu_down() to the variable .cpuinit.data:cpu_chain
WARNING: vmlinux.o(.text+0x75d4d): Section mismatch in reference from the function _cpu_down() to the variable .cpuinit.data:cpu_chain
WARNING: vmlinux.o(.text+0x75de4): Section mismatch in reference from the function _cpu_down() to the variable .cpuinit.data:cpu_chain
WARNING: vmlinux.o(.text+0x75e33): Section mismatch in reference from the function _cpu_down() to the variable .cpuinit.data:cpu_chain

cpu_down is only used from code surrounded by HOTPLUG_CPU so any references to
__cpuinit is OK.

Add a few __ref to tech modpost to ignore the references.

This is just papering over the fact that the cpu hotplug code is fragile with
respect to use of HOTPLUG_CPU and in many cases rely on __cpuinit to get rid
of code when HOTPLUG_CPU is not enabled.  For now this is the least invasive
change.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:00 -07:00
Sam Ravnborg
9647155ffb cpu: fix section mismatch warning in unregister_cpu_notifier
Fix following warning:
WARNING: vmlinux.o(.text+0x75f4e): Section mismatch in reference from the function unregister_cpu_notifier() to the variable .cpuinit.data:cpu_chain

We know that unregister_cpu_notifier is using HOTPLUG_CPU
stuff - so ignore these references.
Annotating unregister_cpu_notifier had been another option
but this caused far more warnings since not all callers were
annotated __cpuinit.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:05:59 -07:00
Sripathi Kodi
679c9cd4ac add RUSAGE_THREAD
Add the RUSAGE_THREAD option for the getrusage system call.  This is
essentially Roland's patch from http://lkml.org/lkml/2008/1/18/589, but the
line about RUSAGE_LWP line has been removed, as suggested by Ulrich and
Christoph.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Kerrisk <mtk.manpages@googlemail.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>
2008-04-29 08:05:59 -07:00
Nur Hussein
95b570c9ce Taint kernel after WARN_ON(condition)
The kernel is sent to tainted within the warn_on_slowpath() function, and
whenever a warning occurs the new taint flag 'W' is set.  This is useful to
know if a warning occurred before a BUG by preserving the warning as a flag
in the taint state.

This does not work on architectures where WARN_ON has its own definition.
These archs are:
	1. s390
	2. superh
	3. avr32
	4. parisc

The maintainers of these architectures have been added in the Cc: list
in this email to alert them to the situation.

The documentation in oops-tracing.txt has been updated to include the
new flag.

Signed-off-by: Nur Hussein <nurhussein@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.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>
2008-04-29 08:05:59 -07:00
Tom Zanussi
c3270e577c relay: fix splice problem
Splice isn't always incrementing the ppos correctly, which broke
relay splice.

Signed-off-by: Tom Zanussi <zanussi@comcast.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-29 09:48:15 +02:00
Harvey Harrison
b331d259b1 kernel: fix integer as NULL pointer warnings
kernel/cpuset.c:1268:52: warning: Using plain integer as NULL pointer
kernel/pid_namespace.c:95:24: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:29:18 -07:00
Roland McGrath
9d04d9280c ptrace: conditionalize compat_ptrace_request
My recent additions to compat_ptrace_request made it mandatory
for CONFIG_COMPAT arch's to define copy_siginfo_from_user32.
This broke some builds, though they all really should get cleaned
up in that way.

Since all the arch's that actually call compat_ptrace_request have
now been cleaned up to use the generic compat_sys_ptrace, we can
avoid the build problems on the crufty arch's by changing the
conditionals on the definition.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 14:14:36 -07:00
Thomas Gleixner
0c96c5979a hrtimer: raise softirq unlocked to avoid circular lock dependency
The scheduler hrtimer bits in 2.6.25 introduced a circular lock
dependency in a rare code path:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.25-sched-devel.git-x86-latest.git #19
-------------------------------------------------------
X/2980 is trying to acquire lock:
 (&rq->rq_lock_key#2){++..}, at: [<ffffffff80230146>] task_rq_lock+0x56/0xa0

but task is already holding lock:
 (&cpu_base->lock){++..}, at: [<ffffffff80257ae1>] lock_hrtimer_base+0x31/0x60

which lock already depends on the new lock.

The scenario which leads to this is:

posix-timer signal is delivered
 -> posix-timer is rearmed
    timer is already expired in hrtimer_enqueue()
     -> softirq is raised

To prevent this we need to move the raise of the softirq out of the
base->lock protected code path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-04-28 22:22:21 +02:00
Linus Torvalds
513694b5f9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt
* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt:
  hrtimer: timeout too long when using HRTIMER_CB_SOFTIRQ
2008-04-28 09:36:40 -07:00
Andres Salomon
b6f448e99c PM/gxfb: add hook to PM console layer that allows disabling of suspend VT switch
Prior to suspend, we allocate and switch to a new VT; after suspend, we switch
back to the original VT.  This can be slow, and is completely unnecessary if
the framebuffer we're using can restore video properly.

This adds a hook that allows drivers to select whether or not to do this vt
switch, and changes the gxfb driver to call this hook.  It also adds a module
param to gxfb to allow controlling of the vt switch (defaulting to no switch).

(Note: I'm not convinced that console_sem is the best way to protect this, but
we should probably have some form of locking..)

[akpm@linux-foundation.org: build fix]
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:36 -07:00
Masami Hiramatsu
26b31c1908 kprobes: add (un)register_jprobes for batch registration
Introduce unregister_/register_jprobes() for jprobe batch registration.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:32 -07:00
Masami Hiramatsu
4a296e07c3 kprobes: add (un)register_kretprobes for batch registration
Introduce unregister_/register_kretprobes() for kretprobe batch registration.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:32 -07:00
Masami Hiramatsu
9861668f74 kprobes: add (un)register_kprobes for batch registration
Introduce unregister_/register_kprobes() for kprobe batch registration.  This
can reduce waiting time for synchronized_sched() when a lot of probes have to
be unregistered at once.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:32 -07:00
Srinivasa Ds
3d8d996e0c kprobes: prevent probing of preempt_schedule()
Prohibit users from probing preempt_schedule().  One way of prohibiting the
user from probing functions is by marking such functions with __kprobes.  But
this method doesn't work for those functions, which are already marked to
different section like preempt_schedule() (belongs to __sched section).  So we
use blacklist approach to refuse user from probing these functions.

In blacklist approach we populate the blacklisted function's starting address
and its size in kprobe_blacklist structure.  Then we verify the user specified
address against start and end of the blacklisted function.  So any attempt to
register probe on blacklisted functions will be rejected.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:32 -07:00
Andrew G. Morgan
3898b1b4eb capabilities: implement per-process securebits
Filesystem capability support makes it possible to do away with (set)uid-0
based privilege and use capabilities instead.  That is, with filesystem
support for capabilities but without this present patch, it is (conceptually)
possible to manage a system with capabilities alone and never need to obtain
privilege via (set)uid-0.

Of course, conceptually isn't quite the same as currently possible since few
user applications, certainly not enough to run a viable system, are currently
prepared to leverage capabilities to exercise privilege.  Further, many
applications exist that may never get upgraded in this way, and the kernel
will continue to want to support their setuid-0 base privilege needs.

Where pure-capability applications evolve and replace setuid-0 binaries, it is
desirable that there be a mechanisms by which they can contain their
privilege.  In addition to leveraging the per-process bounding and inheritable
sets, this should include suppressing the privilege of the uid-0 superuser
from the process' tree of children.

The feature added by this patch can be leveraged to suppress the privilege
associated with (set)uid-0.  This suppression requires CAP_SETPCAP to
initiate, and only immediately affects the 'current' process (it is inherited
through fork()/exec()).  This reimplementation differs significantly from the
historical support for securebits which was system-wide, unwieldy and which
has ultimately withered to a dead relic in the source of the modern kernel.

With this patch applied a process, that is capable(CAP_SETPCAP), can now drop
all legacy privilege (through uid=0) for itself and all subsequently
fork()'d/exec()'d children with:

  prctl(PR_SET_SECUREBITS, 0x2f);

This patch represents a no-op unless CONFIG_SECURITY_FILE_CAPABILITIES is
enabled at configure time.

[akpm@linux-foundation.org: fix uninitialised var warning]
[serue@us.ibm.com: capabilities: use cap_task_prctl when !CONFIG_SECURITY]
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Reviewed-by: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Paul Moore <paul.moore@hp.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Lee Schermerhorn
846a16bf0f mempolicy: rename mpol_copy to mpol_dup
This patch renames mpol_copy() to mpol_dup() because, well, that's what it
does.  Like, e.g., strdup() for strings, mpol_dup() takes a pointer to an
existing mempolicy, allocates a new one and copies the contents.

In a later patch, I want to use the name mpol_copy() to copy the contents from
one mempolicy to another like, e.g., strcpy() does for strings.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Lee Schermerhorn
f0be3d32b0 mempolicy: rename mpol_free to mpol_put
This is a change that was requested some time ago by Mel Gorman.  Makes sense
to me, so here it is.

Note: I retain the name "mpol_free_shared_policy()" because it actually does
free the shared_policy, which is NOT a reference counted object.  However, ...

The mempolicy object[s] referenced by the shared_policy are reference counted,
so mpol_put() is used to release the reference held by the shared_policy.  The
mempolicy might not be freed at this time, because some task attached to the
shared object associated with the shared policy may be in the process of
allocating a page based on the mempolicy.  In that case, the task performing
the allocation will hold a reference on the mempolicy, obtained via
mpol_shared_policy_lookup().  The mempolicy will be freed when all tasks
holding such a reference have called mpol_put() for the mempolicy.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Ken'ichi Ohmichi
122c7a5905 vmcoreinfo: add page flags values
Add some values of page flags to the vmcoreinfo data.

The vmcoreinfo data has the minimum debugging information only for dump
filtering.  makedumpfile (dump filtering command) gets it to distinguish
unnecessary pages, and makedumpfile creates a small dumpfile.

An old makedumpfile (v1.2.4 or before) had assumed some values of page flags
internally, and this implementation could not follow the change of these
values.  For example, Christoph Lameter is changing these values by the
follwing patch: http://lkml.org/lkml/2008/2/29/463

So a new makedumpfile (v1.2.5) came to need these values and I created this
patch to let the kernel output them.

Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:23 -07:00
Christoph Lameter
97965478a6 mm: Get rid of __ZONE_COUNT
It was used to compensate because MAX_NR_ZONES was not available to the
#ifdefs.  Export MAX_NR_ZONES via the new mechanism and get rid of
__ZONE_COUNT.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:22 -07:00
Christoph Lameter
9223b4190f pageflags: get rid of FLAGS_RESERVED
NR_PAGEFLAGS specifies the number of page flags we are using.  From that we
can calculate the number of bits leftover that can be used for zone, node (and
maybe the sections id).  There is no need anymore for FLAGS_RESERVED if we use
NR_PAGEFLAGS.

Use the new methods to make NR_PAGEFLAGS available via the preprocessor.
NR_PAGEFLAGS is used to calculate field boundaries in the page flags fields.
These field widths have to be available to the preprocessor.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Miller <davem@davemloft.net>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:21 -07:00
Christoph Lameter
1cdf25d704 kbuild: create a way to create preprocessor constants from C expressions
The use of enums create constants that are not available to the preprocessor
when building the kernel (f.e.  MAX_NR_ZONES).

Arch code already has a way to export constants calculated to the preprocessor
through the asm-offsets.c file.  Generate something similar for the core
kernel through kbuild.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:21 -07:00
Mel Gorman
19770b3260 mm: filter based on a nodemask as well as a gfp_mask
The MPOL_BIND policy creates a zonelist that is used for allocations
controlled by that mempolicy.  As the per-node zonelist is already being
filtered based on a zone id, this patch adds a version of __alloc_pages() that
takes a nodemask for further filtering.  This eliminates the need for
MPOL_BIND to create a custom zonelist.

A positive benefit of this is that allocations using MPOL_BIND now use the
local node's distance-ordered zonelist instead of a custom node-id-ordered
zonelist.  I.e., pages will be allocated from the closest allowed node with
available memory.

[Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask]
[Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:19 -07:00
Mel Gorman
dd1a239f6f mm: have zonelist contains structs with both a zone pointer and zone_idx
Filtering zonelists requires very frequent use of zone_idx().  This is costly
as it involves a lookup of another structure and a substraction operation.  As
the zone_idx is often required, it should be quickly accessible.  The node idx
could also be stored here if it was found that accessing zone->node is
significant which may be the case on workloads where nodemasks are heavily
used.

This patch introduces a struct zoneref to store a zone pointer and a zone
index.  The zonelist then consists of an array of these struct zonerefs which
are looked up as necessary.  Helpers are given for accessing the zone index as
well as the node index.

[kamezawa.hiroyu@jp.fujitsu.com: Suggested struct zoneref instead of embedding information in pointers]
[hugh@veritas.com: mm-have-zonelist: fix memcg ooms]
[hugh@veritas.com: just return do_try_to_free_pages]
[hugh@veritas.com: do_try_to_free_pages gfp_mask redundant]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <clameter@sgi.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:18 -07:00
Al Viro
8b67dca942 [PATCH] new predicate - AUDIT_FILETYPE
Argument is S_IF... | <index>, where index is normally 0 or 1.
Triggers if chosen element of ctx->names[] is present and the
mode of object in question matches the upper bits of argument.
I.e. for things like "is the argument of that chmod a directory",
etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:28:37 -04:00
Pavel Emelyanov
4a761b8c1d [patch 2/2] Use find_task_by_vpid in audit code
The pid to lookup a task by is passed inside audit code via netlink message.

Thanks to Denis Lunev, netlink packets are now (since 2.6.24) _always_
processed in the context of the sending task.  So this is correct to lookup
the task with find_task_by_vpid() here.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:28:30 -04:00
Harvey Harrison
7719e437fa [PATCH 2/2] audit: fix sparse shadowed variable warnings
Use msglen as the identifier.
kernel/audit.c:724:10: warning: symbol 'len' shadows an earlier one
kernel/audit.c:575:8: originally declared here

Don't use ino_f to check the inode field at the end of the functions.
kernel/auditfilter.c:429:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:420:21: originally declared here
kernel/auditfilter.c:542:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:529:21: originally declared here

i always used as a counter for a for loop and initialized to zero before
use.  Eliminate the inner i variables.
kernel/auditsc.c:1295:8: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here
kernel/auditsc.c:1320:7: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:28:17 -04:00
Harvey Harrison
c782f242f0 [PATCH 1/2] audit: move extern declarations to audit.h
Leave audit_sig_{uid|pid|sid} protected by #ifdef CONFIG_AUDITSYSCALL.

Noticed by sparse:
kernel/audit.c:73:6: warning: symbol 'audit_ever_enabled' was not declared. Should it be static?
kernel/audit.c💯8: warning: symbol 'audit_sig_uid' was not declared. Should it be static?
kernel/audit.c:101:8: warning: symbol 'audit_sig_pid' was not declared. Should it be static?
kernel/audit.c:102:6: warning: symbol 'audit_sig_sid' was not declared. Should it be static?
kernel/audit.c:117:23: warning: symbol 'audit_ih' was not declared. Should it be static?
kernel/auditfilter.c:78:18: warning: symbol 'audit_filter_list' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:28:04 -04:00
Eric Paris
b556f8ad58 Audit: standardize string audit interfaces
This patch standardized the string auditing interfaces.  No userspace
changes will be visible and this is all just cleanup and consistancy
work.  We have the following string audit interfaces to use:

void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len);

void audit_log_n_string(struct audit_buffer *ab, const char *buf, size_t n);
void audit_log_string(struct audit_buffer *ab, const char *buf);

void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t n);
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string);

This may be the first step to possibly fixing some of the issues that
people have with the string output from the kernel audit system.  But we
still don't have an agreed upon solution to that problem.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:19:22 -04:00
Eric Paris
f09ac9db2a Audit: stop deadlock from signals under load
A deadlock is possible between kauditd and auditd under load if auditd
receives a signal.  When auditd receives a signal it sends a netlink
message to the kernel asking for information about the sender of the
signal.  In that same context the audit system will attempt to send a
netlink message back to the userspace auditd.  If kauditd has already
filled the socket buffer (see netlink_attachskb()) auditd will now put
itself to sleep waiting for room to send the message.  Since auditd is
responsible for draining that socket we have a deadlock.  The fix, since
the response from the kernel does not need to be synchronous is to send
the signal information back to auditd in a separate thread.  And thus
auditd can continue to drain the audit queue normally.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:19:13 -04:00
Eric Paris
f3d357b092 Audit: save audit_backlog_limit audit messages in case auditd comes back
This patch causes the kernel audit subsystem to store up to
audit_backlog_limit messages for use by auditd if it ever appears
sometime in the future in userspace.  This is useful to collect audit
messages during bootup and even when auditd is stopped.  This is NOT a
reliable mechanism, it does not ever call audit_panic, nor should it.
audit_log_lost()/audit_panic() are called during the normal delivery
mechanism.  The messages are still sent to printk/syslog as usual and if
too many messages appear to be queued they will be silently discarded.

I liked doing it by default, but this patch only uses the queue in
question if it was booted with audit=1 or if the kernel was built
enabling audit by default.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:19:04 -04:00
Eric Paris
2532386f48 Audit: collect sessionid in netlink messages
Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages.  This patch adds that information to netlink messages
so we can audit who sent netlink messages.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 06:18:03 -04:00
Eric Paris
436c405c7d Audit: end printk with newline
A couple of audit printk statements did not have a newline.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-28 04:45:07 -04:00
Bodo Stroesser
d7b41a24bf hrtimer: timeout too long when using HRTIMER_CB_SOFTIRQ
When using hrtimer with timer->cb_mode == HRTIMER_CB_SOFTIRQ
in some cases the clockevent is not programmed.
This happens, if:
 - a timer is rearmed while it's state is HRTIMER_STATE_CALLBACK
 - hrtimer_reprogram() returns -ETIME, when it is called after
   CALLBACK is finished. This occurs if the new timer->expires
   is in the past when CALLBACK is done.
In this case, the timer needs to be removed from the tree and put
onto the pending list again.

The patch is against 2.6.22.5, but AFAICS, it is relevant
for 2.6.25 also (in run_hrtimer_pending()).

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-27 18:26:43 +02:00
Carsten Otte
402b08622d s390: KVM preparation: provide hook to enable pgstes in user pagetable
The SIE instruction on s390 uses the 2nd half of the page table page to
virtualize the storage keys of a guest. This patch offers the s390_enable_sie
function, which reorganizes the page tables of a single-threaded process to
reserve space in the page table:
s390_enable_sie makes sure that the process is single threaded and then uses
dup_mm to create a new mm with reorganized page tables. The old mm is freed
and the process has now a page status extended field after every page table.

Code that wants to exploit pgstes should SELECT CONFIG_PGSTE.

This patch has a small common code hit, namely making dup_mm non-static.

Edit (Carsten): I've modified Martin's patch, following Jeremy Fitzhardinge's
review feedback. Now we do have the prototype for dup_mm in
include/linux/sched.h. Following Martin's suggestion, s390_enable_sie() does now
call task_lock() to prevent race against ptrace modification of mm_users.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 12:00:40 +03:00
Al Viro
50704516f3 Fix uninitialized 'copy' in unshare_files
Arrgghhh...

Sorry about that, I'd been sure I'd folded that one, but it actually got
lost.  Please apply - that breaks execve().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-26 09:24:31 -07:00
Linus Torvalds
bc84e0a160 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:
  [PATCH] sanitize locate_fd()
  [PATCH] sanitize unshare_files/reset_files_struct
  [PATCH] sanitize handling of shared descriptor tables in failing execve()
  [PATCH] close race in unshare_files()
  [PATCH] restore sane ->umount_begin() API
  cifs: timeout dfs automounts +little fix.
2008-04-25 19:05:55 -07:00
Linus Torvalds
6e18933f2b Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [PATCH] Build fix for CONFIG_NUMA=y && CONFIG_SMP=n
  [IA64] fix bootmem regression on Altix
2008-04-25 12:50:00 -07:00
Linus Torvalds
0b79dada97 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes:
  sched: fix share (re)distribution
  softlockup: fix NOHZ wakeup
  seqlock: livelock fix
2008-04-25 12:47:56 -07:00
Al Viro
3b1253880b [PATCH] sanitize unshare_files/reset_files_struct
* let unshare_files() give caller the displaced files_struct
* don't bother with grabbing reference only to drop it in the
  caller if it hadn't been shared in the first place
* in that form unshare_files() is trivially implemented via
  unshare_fd(), so we eliminate the duplicate logics in fork.c
* reset_files_struct() is not just only called for current;
  it will break the system if somebody ever calls it for anything
  else (we can't modify ->files of somebody else).  Lose the
  task_struct * argument.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-25 09:23:59 -04:00
Al Viro
fd8328be87 [PATCH] sanitize handling of shared descriptor tables in failing execve()
* unshare_files() can fail; doing it after irreversible actions is wrong
  and de_thread() is certainly irreversible.
* since we do it unconditionally anyway, we might as well do it in do_execve()
  and save ourselves the PITA in binfmt handlers, etc.
* while we are at it, binfmt_som actually leaked files_struct on failure.

As a side benefit, unshare_files(), put_files_struct() and reset_files_struct()
become unexported.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-25 09:23:53 -04:00
Al Viro
6b335d9c80 [PATCH] close race in unshare_files()
updating current->files requires task_lock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-25 09:23:48 -04:00
David Miller
5a9d3225a0 sched: use alloc_bootmem() instead of alloc_bootmem_low()
There is no guarantee that there is physical ram below 4GB, and in
fact many boxes don't have exactly that.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 09:53:06 +02:00
Peter Zijlstra
3f5087a2ba sched: fix share (re)distribution
fix __aggregate_redistribute_shares() related lockup reported by
David S. Miller.

The problem this code tries to solve is 'accurately' calculating the 'fair'
share of the group weight for each cpu. The current code falls back to a global
group rebalance in case the sched_domain's span it looks at has no shares, but
does have tasks.

The reason it gets stuck here, is because its inherently racy - if someone
steals the last task after we compute the agg->rq_weight, but before we
rebalance, we'll never get out of the loop.

We could of course go fix that, but while looking at this issue I found that
this 'fallback' wasn't nearly as rare as I'd hoped it to be. In fact its quite
common - and given it walks the whole machine, thats very bad.

The new approach is simple (why didn't I think of it before?), we set the
aggregate shares to the full task group weight, and each larger sched domain
that encounters an aggregate shares larger than the weight, clips it (it
already re-distributes anyway).

This nicely converges to the desired global picture where the sum of all
shares equals the task group weight.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 00:25:08 +02:00
Ingo Molnar
126e01bf92 softlockup: fix NOHZ wakeup
David Miller reported:

|--------------->
the following commit:

| commit 27ec440779
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Thu Feb 28 21:00:21 2008 +0100
|
|     sched: make cpu_clock() globally synchronous
|
|     Alexey Zaytsev reported (and bisected) that the introduction of
|     cpu_clock() in printk made the timestamps jump back and forth.
|
|     Make cpu_clock() more reliable while still keeping it fast when it's
|     called frequently.
|
|     Signed-off-by: Ingo Molnar <mingo@elte.hu>

causes watchdog triggers when a cpu exits NOHZ state when it has been
there for >= the soft lockup threshold, for example here are some
messages from a 128 cpu Niagara2 box:

[  168.106406] BUG: soft lockup - CPU#11 stuck for 128s! [dd:3239]
[  168.989592] BUG: soft lockup - CPU#21 stuck for 86s! [swapper:0]
[  168.999587] BUG: soft lockup - CPU#29 stuck for 91s! [make:4511]
[  168.999615] BUG: soft lockup - CPU#2 stuck for 85s! [swapper:0]
[  169.020514] BUG: soft lockup - CPU#37 stuck for 91s! [swapper:0]
[  169.020514] BUG: soft lockup - CPU#45 stuck for 91s! [sh:4515]
[  169.020515] BUG: soft lockup - CPU#69 stuck for 92s! [swapper:0]
[  169.020515] BUG: soft lockup - CPU#77 stuck for 92s! [swapper:0]
[  169.020515] BUG: soft lockup - CPU#61 stuck for 92s! [swapper:0]
[  169.112554] BUG: soft lockup - CPU#85 stuck for 92s! [swapper:0]
[  169.112554] BUG: soft lockup - CPU#101 stuck for 92s! [swapper:0]
[  169.112554] BUG: soft lockup - CPU#109 stuck for 92s! [swapper:0]
[  169.112554] BUG: soft lockup - CPU#117 stuck for 92s! [swapper:0]
[  169.171483] BUG: soft lockup - CPU#40 stuck for 80s! [dd:3239]
[  169.331483] BUG: soft lockup - CPU#13 stuck for 86s! [swapper:0]
[  169.351500] BUG: soft lockup - CPU#43 stuck for 101s! [dd:3239]
[  169.531482] BUG: soft lockup - CPU#9 stuck for 129s! [mkdir:4565]
[  169.595754] BUG: soft lockup - CPU#20 stuck for 93s! [swapper:0]
[  169.626787] BUG: soft lockup - CPU#52 stuck for 93s! [swapper:0]
[  169.626787] BUG: soft lockup - CPU#84 stuck for 92s! [swapper:0]
[  169.636812] BUG: soft lockup - CPU#116 stuck for 94s! [swapper:0]

It's simple enough to trigger this by doing a 10 minute sleep after a
fresh bootup then starting a parallel kernel build.

I suspect this might be reintroducing a problem we've had and fixed
before, see the thread:

http://marc.info/?l=linux-kernel&m=119546414004065&w=2
<---------------|

touch the softlockup watchdog when exiting NOHZ state - we are
obviously not locked up.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-25 00:25:08 +02:00
Mike Travis
03970f065d [PATCH] Build fix for CONFIG_NUMA=y && CONFIG_SMP=n
Regression caused by 434d53b00d

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-04-24 14:40:29 -07:00
Russ Anderson
472613b961 [IA64] fix bootmem regression on Altix
A recent change prevents SGI Altix from booting.
This patch fixes the problem.

The regresson was introduced in commit 434d53b00d

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-04-24 14:21:21 -07:00
Linus Torvalds
b0d19a378a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  iwlwifi: Fix built-in compilation of iwlcore
  net: Unexport move_addr_to_{kernel,user}
  rt2x00: Select LEDS_CLASS.
  iwlwifi: Select LEDS_CLASS.
  leds: Do not guard NEW_LEDS with HAS_IOMEM
  [IPSEC]: Fix catch-22 with algorithm IDs above 31
  time: Export set_normalized_timespec.
  tcp: Make use of before macro in tcp_input.c
  hamradio: Remove unneeded and deprecated cli()/sti() calls in dmascc.c
  [NETNS]: Remove empty ->init callback.
  [DCCP]: Convert do_gettimeofday() to getnstimeofday().
  [NETNS]: Don't initialize err variable twice.
  [NETNS]: The ip6_fib_timer can work with garbage on net namespace stop.
  [IPV4]: Convert do_gettimeofday() to getnstimeofday().
  [IPV4]: Make icmp_sk_init() static.
  [IPV6]: Make struct ip6_prohibit_entry_template static.
  tcp: Trivial fix to correct function name in a comment in net/ipv4/tcp.c
  [NET]: Expose netdevice dev_id through sysfs
  skbuff: fix missing kernel-doc notation
  [ROSE]: Fix soft lockup wrt. rose_node_list_lock
2008-04-23 12:23:45 -07:00
Linus Torvalds
94bc891b00 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:
  [PATCH] get rid of __exit_files(), __exit_fs() and __put_fs_struct()
  [PATCH] proc_readfd_common() race fix
  [PATCH] double-free of inode on alloc_file() failure exit in create_write_pipe()
  [PATCH] teach seq_file to discard entries
  [PATCH] umount_tree() will unhash everything itself
  [PATCH] get rid of more nameidata passing in namespace.c
  [PATCH] switch a bunch of LSM hooks from nameidata to path
  [PATCH] lock exclusively in collect_mounts() and drop_collected_mounts()
  [PATCH] move a bunch of declarations to fs/internal.h
2008-04-22 18:28:34 -07:00
Al Viro
1ec7f1ddbe [PATCH] get rid of __exit_files(), __exit_fs() and __put_fs_struct()
The only reason to have separated __...() for those was to keep them inlined
for local users in exit.c.  Since Alexey removed the inline on those, there's
no reason whatsoever to keep them around; just collapse with normal variants.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-22 19:55:09 -04:00
Randy Dunlap
73486722b7 kernel-doc: fix sched.c missing parameter
Add missing kernel-doc in kernel/sched.c:

Warning(linux-2.6.25-git3//kernel/sched.c:7044): No description found for parameter 'span'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-22 13:48:02 -07:00
YOSHIFUJI Hideaki
7c3f944e29 time: Export set_normalized_timespec.
Sorry I have just realized set_normalized_timespec() (used in
timespec_sub()) is not exported, and link will fail because of it...

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-21 19:45:12 -07:00
Linus Torvalds
e9b62693ae Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial: (24 commits)
  DOC:  A couple corrections and clarifications in USB doc.
  Generate a slightly more informative error msg for bad HZ
  fix typo "is" -> "if" in Makefile
  ext*: spelling fix prefered -> preferred
  DOCUMENTATION:  Use newer DEFINE_SPINLOCK macro in docs.
  KEYS:  Fix the comment to match the file name in rxrpc-type.h.
  RAID: remove trailing space from printk line
  DMA engine: typo fixes
  Remove unused MAX_NODES_SHIFT
  MAINTAINERS: Clarify access to OCFS2 development mailing list.
  V4L: Storage class should be before const qualifier (sn9c102)
  V4L: Storage class should be before const qualifier
  sonypi: Storage class should be before const qualifier
  intel_menlow: Storage class should be before const qualifier
  DVB: Storage class should be before const qualifier
  arm: Storage class should be before const qualifier
  ALSA: Storage class should be before const qualifier
  acpi: Storage class should be before const qualifier
  firmware_sample_driver.c: fix coding style
  MAINTAINERS: Add ati_remote2 driver
  ...

Fixed up trivial conflicts in firmware_sample_driver.c
2008-04-21 16:36:46 -07:00
Linus Torvalds
bda0c0afa7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6: (42 commits)
  PCI: Change PCI subsystem MAINTAINER
  PCI: pci-iommu-iotlb-flushing-speedup
  PCI: pci_setup_bridge() mustn't be __devinit
  PCI: pci_bus_size_cardbus() mustn't be __devinit
  PCI: pci_scan_device() mustn't be __devinit
  PCI: pci_alloc_child_bus() mustn't be __devinit
  PCI: replace remaining __FUNCTION__ occurrences
  PCI: Hotplug: fakephp: Return success, not ENODEV, when bus rescan is triggered
  PCI: Hotplug: Fix leaks in IBM Hot Plug Controller Driver - ibmphp_init_devno()
  PCI: clean up resource alignment management
  PCI: aerdrv_acpi.c: remove unneeded NULL check
  PCI: Update VIA CX700 quirk
  PCI: Expose PCI VPD through sysfs
  PCI: iommu: iotlb flushing
  PCI: simplify quirk debug output
  PCI: iova RB tree setup tweak
  PCI: parisc: use generic pci_enable_resources()
  PCI: ppc: use generic pci_enable_resources()
  PCI: powerpc: use generic pci_enable_resources()
  PCI: ia64: use generic pci_enable_resources()
  ...
2008-04-21 15:58:35 -07:00
Roland McGrath
e16b278164 ptrace: compat_ptrace_request siginfo
This adds support for PTRACE_GETSIGINFO and PTRACE_SETSIGINFO in
compat_ptrace_request.  It relies on existing arch definitions for
copy_siginfo_to_user32 and copy_siginfo_from_user32.

On powerpc, this fixes a longstanding regression of 32-bit ptrace
calls on 64-bit kernels vs native calls (64-bit calls or 32-bit
kernels).  This can be seen in a 32-bit call using PTRACE_GETSIGINFO
to examine e.g. siginfo_t.si_addr from a signal that sets it.
(This was broken as of 2.6.24 and, I presume, many or all prior versions.)

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-21 15:53:41 -07:00
Linus Torvalds
5dfeaef895 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt:
  hrtimer: optimize the softirq time optimization
  hrtimer: reduce calls to hrtimer_get_softirq_time()
  clockevents: fix typo in tick-broadcast.c
  jiffies: add time_is_after_jiffies and others which compare with jiffies
2008-04-21 15:43:43 -07:00
Linus Torvalds
429f731dea Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
  Deprecate the asm/semaphore.h files in feature-removal-schedule.
  Convert asm/semaphore.h users to linux/semaphore.h
  security: Remove unnecessary inclusions of asm/semaphore.h
  lib: Remove unnecessary inclusions of asm/semaphore.h
  kernel: Remove unnecessary inclusions of asm/semaphore.h
  include: Remove unnecessary inclusions of asm/semaphore.h
  fs: Remove unnecessary inclusions of asm/semaphore.h
  drivers: Remove unnecessary inclusions of asm/semaphore.h
  net: Remove unnecessary inclusions of asm/semaphore.h
  arch: Remove unnecessary inclusions of asm/semaphore.h
2008-04-21 15:41:27 -07:00
Linus Torvalds
ec965350bb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel: (62 commits)
  sched: build fix
  sched: better rt-group documentation
  sched: features fix
  sched: /debug/sched_features
  sched: add SCHED_FEAT_DEADLINE
  sched: debug: show a weight tree
  sched: fair: weight calculations
  sched: fair-group: de-couple load-balancing from the rb-trees
  sched: fair-group scheduling vs latency
  sched: rt-group: optimize dequeue_rt_stack
  sched: debug: add some debug code to handle the full hierarchy
  sched: fair-group: SMP-nice for group scheduling
  sched, cpuset: customize sched domains, core
  sched, cpuset: customize sched domains, docs
  sched: prepatory code movement
  sched: rt: multi level group constraints
  sched: task_group hierarchy
  sched: fix the task_group hierarchy for UID grouping
  sched: allow the group scheduler to have multiple levels
  sched: mix tasks and groups
  ...
2008-04-21 15:40:24 -07:00
Pavel Machek
f5264481c8 trivial: small cleanups
These are small cleanups all over the tree.

Trivial style and comment changes to
  fs/select.c, kernel/signal.c, kernel/stop_machine.c & mm/pdflush.c

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
2008-04-21 22:15:06 +00:00
Thomas Gleixner
259aae864c hrtimer: optimize the softirq time optimization
The previous optimization did not take the case into account where a
clock provides its own softirq_get_time() function.

Check for the availablitiy of the clock get time function first and
then check if we need to retrieve the time for both clocks via
hrtimer_softirq_gettime() to avoid a double evaluation of time in that
case as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-21 07:59:51 +02:00
Dimitri Sivanich
833883d9ac hrtimer: reduce calls to hrtimer_get_softirq_time()
It seems that hrtimer_run_queues() is calling hrtimer_get_softirq_time() more
often than it needs to.  This can cause frequent contention on systems with
large numbers of processors/cores.

With this patch, hrtimer_run_queues only calls hrtimer_get_softirq_time() if
there is a pending timer in one of the hrtimer bases, and only once.

This also combines hrtimer_run_queues() and the inline run_hrtimer_queue()
into one function.

[ tglx@linutronix.de: coding style ]

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-21 07:59:51 +02:00
Glauber Costa
833df317f9 clockevents: fix typo in tick-broadcast.c
braodcast -> broadcast

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-21 07:59:51 +02:00
Ivan Kokshaysky
884525655d PCI: clean up resource alignment management
Done per Linus' request and suggestions. Linus has explained that
better than I'll be able to explain:

On Thu, Mar 27, 2008 at 10:12:10AM -0700, Linus Torvalds wrote:
> Actually, before we go any further, there might be a less intrusive
> alternative: add just a couple of flags to the resource flags field (we
> still have something like 8 unused bits on 32-bit), and use those to
> implement a generic "resource_alignment()" routine.
>
> Two flags would do it:
>
>  - IORESOURCE_SIZEALIGN: size indicates alignment (regular PCI device
>    resources)
>
>  - IORESOURCE_STARTALIGN: start field is alignment (PCI bus resources
>    during probing)
>
> and then the case of both flags zero (or both bits set) would actually be
> "invalid", and we would also clear the IORESOURCE_STARTALIGN flag when we
> actually allocate the resource (so that we don't use the "start" field as
> alignment incorrectly when it no longer indicates alignment).
>
> That wouldn't be totally generic, but it would have the nice property of
> automatically at least add sanity checking for that whole "res->start has
> the odd meaning of 'alignment' during probing" and remove the need for a
> new field, and it would allow us to have a generic "resource_alignment()"
> routine that just gets a resource pointer.

Besides, I removed IORESOURCE_BUS_HAS_VGA flag which was unused for ages.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-20 21:47:08 -07:00
Ingo Molnar
486fdae214 sched: build fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:01 +02:00
Ingo Molnar
c24b7c5244 sched: features fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
f00b45c145 sched: /debug/sched_features
provide a text based interface to the scheduler features; this saves the
'user' from setting bits using decimal arithmetic.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Ingo Molnar
06379aba52 sched: add SCHED_FEAT_DEADLINE
unused at the moment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
7ba2e74ab5 sched: debug: show a weight tree
Print a tree of weights.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
8f1bc385cf sched: fair: weight calculations
In order to level the hierarchy, we need to calculate load based on the
root view. That is, each task's load is in the same unit.

             A
            / \
           B   1
          / \
         2   3

To compute 1's load we do:

	   weight(1)
	--------------
	 rq_weight(A)

To compute 2's load we do:

	  weight(2)      weight(B)
	------------ * -----------
	rq_weight(B)   rw_weight(A)

This yields load fractions in comparable units.

The consequence is that it changes virtual time. We used to have:

                time_{i}
  vtime_{i} = ------------
               weight_{i}

  vtime = \Sum vtime_{i} = time / rq_weight.

But with the new way of load calculation we get that vtime equals time.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
4a55bd5e97 sched: fair-group: de-couple load-balancing from the rb-trees
De-couple load-balancing from the rb-trees, so that I can change their
organization.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
ac884dec6d sched: fair-group scheduling vs latency
Currently FAIR_GROUP sched grows the scheduler latency outside of
sysctl_sched_latency, invert this so it stays within.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
58d6c2d72f sched: rt-group: optimize dequeue_rt_stack
Now that the group hierarchy can have an arbitrary depth the O(n^2) nature
of RT task dequeues will really hurt. Optimize this by providing space to
store the tree path, so we can walk it the other way.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
d19ca30874 sched: debug: add some debug code to handle the full hierarchy
Add some extra debug output so we can get a better overview of the
full hierarchy.

We print the cgroup path after each cfs_rq, so we can see what group
we're looking at.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
18d95a2832 sched: fair-group: SMP-nice for group scheduling
Implement SMP nice support for the full group hierarchy.

On each load-balance action, compile a sched_domain wide view of the full
task_group tree. We compute the domain wide view when walking down the
hierarchy, and readjust the weights when walking back up.

After collecting and readjusting the domain wide view, we try to balance the
tasks within the task_groups. The current approach is a naively balance each
task group until we've moved the targeted amount of load.

Inspired by Srivatsa Vaddsgiri's previous code and Abhishek Chandra's H-SMP
paper.

XXX: there will be some numerical issues due to the limited nature of
     SCHED_LOAD_SCALE wrt to representing a task_groups influence on the
     total weight. When the tree is deep enough, or the task weight small
     enough, we'll run out of bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Abhishek Chandra <chandra@cs.umn.edu>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Hidetoshi Seto
1d3504fcf5 sched, cpuset: customize sched domains, core
[rebased for sched-devel/latest]

 - Add a new cpuset file, having levels:
     sched_relax_domain_level

 - Modify partition_sched_domains() and build_sched_domains()
   to take attributes parameter passed from cpuset.

 - Fill newidle_idx for node domains which currently unused but
   might be required if sched_relax_domain_level become higher.

 - We can change the default level by boot option 'relax_domain_level='.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
b758149c02 sched: prepatory code movement
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
b40b2e8eb5 sched: rt: multi level group constraints
multi level rt constraints

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
f473aa5e02 sched: task_group hierarchy
Add the full parent<->child relation thing into task_groups as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Peter Zijlstra
eff766a65c sched: fix the task_group hierarchy for UID grouping
UID grouping doesn't actually have a task_group representing the root of
the task_group tree. Add one.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:00 +02:00
Dhaval Giani
ec7dc8ac73 sched: allow the group scheduler to have multiple levels
This patch makes the group scheduler multi hierarchy aware.

[a.p.zijlstra@chello.nl: rt-parts and assorted fixes]
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Dhaval Giani
354d60c2ff sched: mix tasks and groups
This patch allows tasks and groups to exist in the same cfs_rq. With this
change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N)
fairness model where M tasks and N groups exist at the cfs_rq level.

[a.p.zijlstra@chello.nl: rt bits and assorted fixes]
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Ingo Molnar
ea736ed5d3 sched: fix checks
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Peter Zijlstra
112f53f5d7 sched: old sleeper bonus
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
cd8ba7cd9b sched: add new set_cpus_allowed_ptr function
Add a new function that accepts a pointer to the "newly allowed cpus"
cpumask argument.

int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)

The current set_cpus_allowed() function is modified to use the above
but this does not result in an ABI change.  And with some compiler
optimization help, it may not introduce any additional overhead.

Additionally, to enforce the read only nature of the new_mask arg, the
"const" property is migrated to sub-functions called by set_cpus_allowed.
This silences compiler warnings.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
e0982e90cd init: move setup of nr_cpu_ids to as early as possible
Move the setting of nr_cpu_ids from sched_init() to start_kernel()
so that it's available as early as possible.

Note that an arch has the option of setting it even earlier if need be,
but it should not result in a different value than the setup_nr_cpu_ids()
function.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
4bdbaad33d sched: remove another cpumask_t variable from stack
* Remove another cpumask_t variable from stack that was missed in the
      last kernel_sched_c updates.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
39106dcf85 cpumask: use new cpus_scnprintf function
* Cleaned up references to cpumask_scnprintf() and added new
    cpulist_scnprintf() interfaces where appropriate.

  * Fix some small bugs (or code efficiency improvments) for various uses
    of cpumask_scnprintf.

  * Clean up some checkpatch errors.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
7c16ec585c cpumask: reduce stack usage in SD_x_INIT initializers
* Remove empty cpumask_t (and all non-zero/non-null) variables
    in SD_*_INIT macros.  Use memset(0) to clear.  Also, don't
    inline the initializer functions to save on stack space in
    build_sched_domains().

  * Merge change to include/linux/topology.h that uses the new
    node_to_cpumask_ptr function in the nr_cpus_node macro into
    this patch.

Depends on:
	[mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
c5f59f0833 nodemask: use new node_to_cpumask_ptr function
* Use new node_to_cpumask_ptr.  This creates a pointer to the
    cpumask for a given node.  This definition is in mm patch:

	asm-generic-add-node_to_cpumask_ptr-macro.patch

  * Use new set_cpus_allowed_ptr function.

Depends on:
	[mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch
	[sched-devel]: sched: add new set_cpus_allowed_ptr function
	[x86/latest]: x86: add cpus_scnprintf function

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Greg Banks <gnb@melbourne.sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
b53e921ba1 generic: reduce stack pressure in sched_affinity
* Modify sched_affinity functions to pass cpumask_t variables by reference
    instead of by value.

  * Use new set_cpus_allowed_ptr function.

Depends on:
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Cc: Paul Jackson <pj@sgi.com>
Cc: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:59 +02:00
Mike Travis
f9a86fcbbb cpuset: modify cpuset_set_cpus_allowed to use cpumask pointer
* Modify cpuset_cpus_allowed to return the currently allowed cpuset
    via a pointer argument instead of as the function return value.

  * Use new set_cpus_allowed_ptr function.

  * Cleanup CPU_MASK_ALL and NODE_MASK_ALL uses.

Depends on:
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Mike Travis
f70316dace generic: use new set_cpus_allowed_ptr function
* Use new set_cpus_allowed_ptr() function added by previous patch,
    which instead of passing the "newly allowed cpus" cpumask_t arg
    by value,  pass it by pointer:

    -int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
    +int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)

  * Modify CPU_MASK_ALL

Depends on:
	[sched-devel]: sched: add new set_cpus_allowed_ptr function

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Mike Travis
434d53b00d sched: remove fixed NR_CPUS sized arrays in kernel_sched_c
* Change fixed size arrays to per_cpu variables or dynamically allocated
   arrays in sched_init() and sched_init_smp().

     (1) static struct sched_entity *init_sched_entity_p[NR_CPUS];
     (1) static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
     (1) static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
     (1) static struct rt_rq *init_rt_rq_p[NR_CPUS];
	 static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];

     (1) - these arrays are allocated via alloc_bootmem_low()

 * Change sched_domain_debug_one() to use cpulist_scnprintf instead of
   cpumask_scnprintf.  This reduces the output buffer required and improves
   readability when large NR_CPU count machines arrive.

 * In sched_create_group() we allocate new arrays based on nr_cpu_ids.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Mike Travis
d366f8cbc1 cpumask: Cleanup more uses of CPU_MASK and NODE_MASK
*  Replace usages of CPU_MASK_NONE, CPU_MASK_ALL, NODE_MASK_NONE,
    NODE_MASK_ALL to reduce stack requirements for large NR_CPUS
    and MAXNODES counts.

 *  In some cases, the cpumask variable was initialized but then overwritten
    with another value.  This is the case for changes like this:

    -       cpumask_t oldmask = CPU_MASK_ALL;
    +       cpumask_t oldmask;

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Gregory Haskins
9f0e738f49 sched: fix cpus_allowed settings
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Dhaval Giani
0297b80339 sched: allow cpuacct stats to be reset
Currently the schedstats implementation does not allow the statistics
to be reset. This patch aims to allow that.

  echo 0 > cpuacct.usage

resets the usage. Any other value is not allowed and returns -EINVAL.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Dhaval Giani
32cd756a80 sched: cleanup cpuacct variable names
Change the variable names to the common convention for the cpuacct
subsystem.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Olof Johansson
48f20a9a94 tasklets: execute tasklets in the same order they were queued
I noticed this when looking at an openswan issue.  Openswan (ab?)uses the
tasklet API to defer processing of packets in some situations, with one
packet per tasklet_action().  I started noticing sequences of
backwards-ordered sequence numbers coming over the wire, since new tasklets
are always queued at the head of the list but processed sequentially.

Convert it to instead append new entries to the tail of the list.  As an
extra bonus, the splicing code in takeover_tasklets() no longer has to
iterate over the list.

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Peter Zijlstra
ac086bc229 sched: rt-group: smp balancing
Currently the rt group scheduling does a per cpu runtime limit, however
the rt load balancer makes no guarantees about an equal spread of real-
time tasks, just that at any one time, the highest priority tasks run.

Solve this by making the runtime limit a global property by borrowing
excessive runtime from the other cpus once the local limit runs out.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:58 +02:00
Peter Zijlstra
d0b27fa778 sched: rt-group: synchonised bandwidth period
Various SMP balancing algorithms require that the bandwidth period
run in sync.

Possible improvements are moving the rt_bandwidth thing into root_domain
and keeping a span per rt_bandwidth which marks throttled cpus.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Peter Zijlstra
79b3feffb1 sched: fix regression with sched yield
Balbir Singh reported:

> 1:mon> t
> [c0000000e7677da0] c000000000067de0 .sys_sched_yield+0x6c/0xbc
> [c0000000e7677e30] c000000000008748 syscall_exit+0x0/0x40
> --- Exception: c01 (System Call) at 00000400001d09e4
> SP (4000664cb10) is in userspace
> 1:mon> r
> cpu 0x1: Vector: 300 (Data Access) at [c0000000e7677aa0]
>     pc: c000000000068e50: .yield_task_fair+0x94/0xc4
>     lr: c000000000067de0: .sys_sched_yield+0x6c/0xbc

the check that should have avoided that is:

        /*
         * Are we the only task in the tree?
         */
        if (unlikely(rq->load.weight == curr->se.load.weight))
                return;

But I guess that overlooks rt tasks, they also increase the load.
So I guess something like this ought to fix it..

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Dmitry Adamushko
19fb518c2a latencytop: optimize LT_BACKTRACEDEPTH loops a bit
There is no need to loop any longer when 'same == 0'.

Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
50df5d6aea sched: remove sysctl_sched_batch_wakeup_granularity
it's unused.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
02e2b83bd2 sched: reenable sync wakeups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
d25ce4cd49 sched: cache hot buddy
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
1fc8afa4c8 sched: feat affine wakeups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
b85d066726 sched: introduce SCHED_FEAT_SYNC_WAKEUPS, turn it off
turn off sync wakeups by default. They are not needed anymore - the
buddy logic should be smart enough to keep the system from
overscheduling.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Peter Zijlstra
0bbd3336ee sched: fix wakeup granularity for buddies
The wakeup buddy logic didn't use the same wakeup granularity logic as the
wakeup preemption did, this might cause the ->next buddy to be selected past
the point where we would have preempted had the task been a single running
instance.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Guillaume Chazarain
15934a3732 sched: fix rq->clock overflows detection with CONFIG_NO_HZ
When using CONFIG_NO_HZ, rq->tick_timestamp is not updated every TICK_NSEC.
We check that the number of skipped ticks matches the clock jump seen in
__update_rq_clock().

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Reynes Philippe
30914a58af sched: sched.c needs tick.h
kernel/sched.c:506: erreur: implicit declaration of function tick_get_tick_sched
kernel/sched.c:506: erreur: invalid type argument of ->
kernel/sched.c:506: erreur: NOHZ_MODE_INACTIVE undeclared (first use in this function)
kernel/sched.c:506: erreur: (Each undeclared identifier is reported only once
kernel/sched.c:506: erreur: for each function it appears in.)

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
27ec440779 sched: make cpu_clock() globally synchronous
Alexey Zaytsev reported (and bisected) that the introduction of
cpu_clock() in printk made the timestamps jump back and forth.

Make cpu_clock() more reliable while still keeping it fast when it's
called frequently.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Ingo Molnar
018d6db4cb sched: re-do "sched: fix fair sleepers"
re-apply:

| commit e22ecef1d2
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Fri Mar 14 22:16:08 2008 +0100
|
|     sched: fix fair sleepers
|
|     Fair sleepers need to scale their latency target down by runqueue
|     weight. Otherwise busy systems will gain ever larger sleep bonus.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:44:57 +02:00
Suresh Siddha
2adee9b30d x86: fpu xstate split fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Suresh Siddha
61c4628b53 x86, fpu: split FPU state from task struct - v5
Split the FPU save area from the task struct. This allows easy migration
of FPU context, and it's generally cleaner. It also allows the following
two optimizations:

1) only allocate when the application actually uses FPU, so in the first
lazy FPU trap. This could save memory for non-fpu using apps. Next patch
does this lazy allocation.

2) allocate the right size for the actual cpu rather than 512 bytes always.
Patches enabling xsave/xrstor support (coming shortly) will take advantage
of this.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Thomas Gleixner
d8bb6f4c16 x86: tsc prevent time going backwards
We already catch most of the TSC problems by sanity checks, but there
is a subtle bug which has been in the code forever. This can cause
time jumps in the range of hours.

This was reported in:
     http://lkml.org/lkml/2007/8/23/96
and
     http://lkml.org/lkml/2008/3/31/23

I was able to reproduce the problem with a gettimeofday loop test on a
dual core and a quad core machine which both have sychronized
TSCs. The TSCs seems not to be perfectly in sync though, but the
kernel is not able to detect the slight delta in the sync check. Still
there exists an extremly small window where this delta can be observed
with a real big time jump. So far I was only able to reproduce this
with the vsyscall gettimeofday implementation, but in theory this
might be observable with the syscall based version as well.

CPU 0 updates the clock source variables under xtime/vyscall lock and
CPU1, where the TSC is slighty behind CPU0, is reading the time right
after the seqlock was unlocked.

The clocksource reference data was updated with the TSC from CPU0 and
the value which is read from TSC on CPU1 is less than the reference
data. This results in a huge delta value due to the unsigned
subtraction of the TSC value and the reference value. This algorithm
can not be changed due to the support of wrapping clock sources like
pm timer.

The huge delta is converted to nanoseconds and added to xtime, which
is then observable by the caller. The next gettimeofday call on CPU1
will show the correct time again as now the TSC has advanced above the
reference value.

To prevent this TSC specific wreckage we need to compare the TSC value
against the reference value and return the latter when it is larger
than the actual TSC value.

I pondered to mark the TSC unstable when the readout is smaller than
the reference value, but this would render an otherwise good and fast
clocksource unusable without a real good reason.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:19:55 +02:00
Erik Bosman
8fb402bccf generic, x86: add prctl commands PR_GET_TSC and PR_SET_TSC
This patch adds prctl commands that make it possible
to deny the execution of timestamp counters in userspace.
If this is not implemented on a specific architecture,
prctl will return -EINVAL.

ned-off-by: Erik Bosman <ejbosman@cs.vu.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-19 19:19:55 +02:00
Matthew Wilcox
a655020753 kernel: Remove unnecessary inclusions of asm/semaphore.h
None of these files use any of the functionality promised by
asm/semaphore.h.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-18 22:17:04 -04:00
Ahmed S. Darwish
04305e4aff Audit: Final renamings and cleanup
Rename the se_str and se_rule audit fields elements to
lsm_str and lsm_rule to avoid confusion.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
2008-04-19 09:59:43 +10:00
Ahmed S. Darwish
9d57a7f9e2 SELinux: use new audit hooks, remove redundant exports
Setup the new Audit LSM hooks for SELinux.
Remove the now redundant exported SELinux Audit interface.

Audit: Export 'audit_krule' and 'audit_field' to the public
since their internals are needed by the implementation of the
new LSM hook 'audit_rule_known'.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
2008-04-19 09:53:46 +10:00
Ahmed S. Darwish
d7a96f3a1a Audit: internally use the new LSM audit hooks
Convert Audit to use the new LSM Audit hooks instead of
the exported SELinux interface.

Basically, use:
security_audit_rule_init
secuirty_audit_rule_free
security_audit_rule_known
security_audit_rule_match

instad of (respectively) :
selinux_audit_rule_init
selinux_audit_rule_free
audit_rule_has_selinux
selinux_audit_rule_match

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
2008-04-19 09:52:37 +10:00
Ahmed S. Darwish
2a862b32f3 Audit: use new LSM hooks instead of SELinux exports
Stop using the following exported SELinux interfaces:
selinux_get_inode_sid(inode, sid)
selinux_get_ipc_sid(ipcp, sid)
selinux_get_task_sid(tsk, sid)
selinux_sid_to_string(sid, ctx, len)
kfree(ctx)

and use following generic LSM equivalents respectively:
security_inode_getsecid(inode, secid)
security_ipc_getsecid*(ipcp, secid)
security_task_getsecid(tsk, secid)
security_sid_to_secctx(sid, ctx, len)
security_release_secctx(ctx, len)

Call security_release_secctx only if security_secid_to_secctx
succeeded.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Reviewed-by: Paul Moore <paul.moore@hp.com>
2008-04-19 09:52:34 +10:00
Linus Torvalds
73e3e6481f Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt
* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt:
  clocksource: make clocksource watchdog cycle through online CPUs
  Documentation: move timer related documentation to a single place
  clockevents: optimise tick_nohz_stop_sched_tick() a bit
  locking: remove unused double_spin_lock()
  hrtimers: simplify lockdep handling
  timers: simplify lockdep handling
  posix-timers: fix shadowed variables
  timer_list: add annotations to workqueue.c
  hrtimer: use nanosleep specific restart_block fields
  hrtimer: add nanosleep specific restart_block member
2008-04-18 08:37:41 -07:00
Linus Torvalds
9732b61123 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb
* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb:
  kgdb: always use icache flush for sw breakpoints
  kgdb: fix SMP NMI kgdb_handle_exception exit race
  kgdb: documentation fixes
  kgdb: allow static kgdbts boot configuration
  kgdb: add documentation
  kgdb: Kconfig fix
  kgdb: add kgdb internal test suite
  kgdb: fix several kgdb regressions
  kgdb: kgdboc pl011 I/O module
  kgdb: fix optional arch functions and probe_kernel_*
  kgdb: add x86 HW breakpoints
  kgdb: print breakpoint removed on exception
  kgdb: clocksource watchdog
  kgdb: fix NMI hangs
  kgdb: fix kgdboc dynamic module configuration
  kgdb: document parameters
  x86: kgdb support
  consoles: polling support, kgdboc
  kgdb: core
  uaccess: add probe_kernel_write()
2008-04-18 08:37:01 -07:00
Linus Torvalds
d7bb545d86 Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
  Remove DEBUG_SEMAPHORE from Kconfig
  Improve semaphore documentation
  Simplify semaphore implementation
  Add down_timeout and change ACPI to use it
  Introduce down_killable()
  Generic semaphore implementation
  Add semaphore.h to kernel_lock.c
  Fix quota.h includes
2008-04-18 08:25:29 -07:00
Linus Torvalds
4cba84b5d6 Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (36 commits)
  [S390] Remove code duplication from monreader / dcssblk.
  [S390] kernel: show last breaking-event-address on oops
  [S390] lowcore: Change type of lowcores softirq_pending to __u32.
  [S390] zcrypt: Comments and kernel-doc cleanup
  [S390] uaccess: Always access the correct address space.
  [S390] Fix a lot of sparse warnings.
  [S390] Convert s390 to GENERIC_CLOCKEVENTS.
  [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h
  [S390] Convert monitor calls to function calls.
  [S390] qdio (new feature): enhancing info-retrieval from QDIO-adapters
  [S390] replace remaining __FUNCTION__ occurrences
  [S390] remove redundant display of free swap space in show_mem()
  [S390] qdio: remove outdated developerworks link.
  [S390] Add debug_register_mode() function to debug feature API
  [S390] crypto: use more descriptive function names for init/exit routines.
  [S390] switch sched_clock to store-clock-extended.
  [S390] zcrypt: add support for large random numbers
  [S390] hw_random: allow rng_dev_read() to return hardware errors.
  [S390] Vertical cpu management.
  [S390] cpu topology support for s390.
  ...
2008-04-18 08:19:15 -07:00
Roland McGrath
18c98b6527 ptrace_signal subroutine
This breaks out the ptrace handling from get_signal_to_deliver into a
new subroutine.  The actual code there doesn't change, and it gets
inlined into nearly identical compiled code.  This makes the function
substantially shorter and thus easier to read, and it nicely isolates
the ptrace magic.

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-18 08:17:57 -07:00
Li Zefan
0e04388f01 cgroup: fix a race condition in manipulating tsk->cg_list
When I ran a test program to fork mass processes and at the same time
'cat /cgroup/tasks', I got the following oops:

  ------------[ cut here ]------------
  kernel BUG at lib/list_debug.c:72!
  invalid opcode: 0000 [#1] SMP
  Pid: 4178, comm: a.out Not tainted (2.6.25-rc9 #72)
  ...
  Call Trace:
   [<c044a5f9>] ? cgroup_exit+0x55/0x94
   [<c0427acf>] ? do_exit+0x217/0x5ba
   [<c0427ed7>] ? do_group_exit+0.65/0x7c
   [<c0427efd>] ? sys_exit_group+0xf/0x11
   [<c0404842>] ? syscall_call+0x7/0xb
   [<c05e0000>] ? init_cyrix+0x2fa/0x479
  ...
  EIP: [<c04df671>] list_del+0x35/0x53 SS:ESP 0068:ebc7df4
  ---[ end trace caffb7332252612b ]---
  Fixing recursive fault but reboot is needed!

After digging into the code and debugging, I finlly found out a race
situation:

				do_exit()
				  ->cgroup_exit()
				    ->if (!list_empty(&tsk->cg_list))
				        list_del(&tsk->cg_list);

  cgroup_iter_start()
    ->cgroup_enable_task_cg_list()
      ->list_add(&tsk->cg_list, ..);

In this case the list won't be deleted though the process has exited.

We got two bug reports in the past, which seem to be the same bug as
this one:
	http://lkml.org/lkml/2008/3/5/332
	http://lkml.org/lkml/2007/10/17/224

Actually sometimes I got oops on list_del, sometimes oops on list_add.
And I can change my test program a bit to trigger other oops.

The patch has been tested both on x86_32 and x86_64.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-18 08:17:57 -07:00
Jason Wessel
1a9a3e76dd kgdb: always use icache flush for sw breakpoints
On the ppc 4xx architecture the instruction cache must be flushed as
well as the data cache.  This patch just makes it generic for all
architectures where CACHE_FLUSH_IS_SAFE is set to 1.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:43 +02:00
Jason Wessel
56fb709329 kgdb: fix SMP NMI kgdb_handle_exception exit race
Fix the problem of protecting the kgdb handle_exception exit
which had an NMI race condition, while trying to restore
normal system operation.

There was a small window after the master processor sets cpu_in_debug
to zero but before it has set kgdb_active to zero where a
non-master processor in an SMP system could receive an NMI and
re-enter the kgdb_wait() loop.

As long as the master processor sets the cpu_in_debug before sending
the cpu roundup the cpu_in_debug variable can also be used to guard
against the race condition.

The kgdb_wait() function no longer needs to check
kgdb_active because it is done in the arch specific code
and handled along with the nmi traps at the low level.
This also allows kgdb_wait() to exit correctly if it was
entered for some unknown reason due to a spurious NMI that
could not be handled by the arch specific code.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:43 +02:00
Jason Wessel
737a460f21 kgdb: fix several kgdb regressions
kgdb core fixes:
- Check to see that mm->mmap_cache is not null before calling
  flush_cache_range(), else on arch=ARM it will cause a fatal
  fault.

- Breakpoints should only be restored if they are in the BP_ACTIVE
  state.

- Fix a typo in comments to "kgdb_register_io_module"

x86 kgdb fixes:
- Fix the x86 arch handler such that on a kill or detach that the
  appropriate cleanup on the single stepping flags gets run.

- Add in the DIE_NMIWATCHDOG call for x86_64

- Touch the nmi watchdog before returning the system to normal
  operation after performing any kind of kgdb operation, else
  the possibility exists to trigger the watchdog.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:40 +02:00
Jason Wessel
b4b8ac524d kgdb: fix optional arch functions and probe_kernel_*
Fix two regressions dealing with the kgdb core.

1) kgdb_skipexception and kgdb_post_primary_code are optional
functions that are only required on archs that need special exception
fixups.

2) The kernel address space scope must be set on any probe_kernel_*
function or archs such as ARCH=arm will not allow access to the kernel
memory space.  As an example, it is required to allow the full kernel
address space is when you the kernel debugger to inspect a system
call.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:39 +02:00
Jason Wessel
64e9ee3095 kgdb: add x86 HW breakpoints
Add HW breakpoints into the arch specific portion of x86 kgdb.  In the
current x86 kernel.org kernels HW breakpoints are changed out in lazy
fashion because there is no infrastructure around changing them when
changing to a kernel task or entering the kernel mode via a system
call.  This lazy approach means that if a user process uses HW
breakpoints the kgdb will loose out.  This is an acceptable trade off
because the developer debugging the kernel is assumed to know what is
going on system wide and would be aware of this trade off.

There is a minor bug fix to the kgdb core so as to correctly call the
hw breakpoint functions with a valid value from the enum.

There is also a minor change to the x86_64 startup code when using
early HW breakpoints.  When the debugger is connected, the cpu startup
code must not zero out the HW breakpoint registers or you cannot hit
the breakpoints you are interested in, in the first place.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:39 +02:00
Jason Wessel
67baf94cd2 kgdb: print breakpoint removed on exception
If kgdb does remove a breakpoint that had a problem on the recursion
check, it should also print the address of the breakpoint.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:39 +02:00
Jason Wessel
7c3078b637 kgdb: clocksource watchdog
In order to not trip the clocksource watchdog, kgdb must touch the
clocksource watchdog on the return to normal system run state.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:38 +02:00
Jason Wessel
dc7d552705 kgdb: core
kgdb core code. Handles the protocol and the arch details.

[ mingo@elte.hu: heavily modified, simplified and cleaned up. ]
[ xemul@openvz.org: use find_task_by_pid_ns ]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-17 20:05:37 +02:00
Matthew Wilcox
714493cd54 Improve semaphore documentation
Move documentation from semaphore.h to semaphore.c as requested by
Andrew Morton.  Also reformat to kernel-doc style and add some more
notes about the implementation.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-17 10:43:01 -04:00
Matthew Wilcox
b17170b2fa Simplify semaphore implementation
By removing the negative values of 'count' and relying on the wait_list to
indicate whether we have any waiters, we can simplify the implementation
by removing the protection against an unlikely race condition.  Thanks to
David Howells for his suggestions.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-17 10:42:54 -04:00
Matthew Wilcox
f1241c87a1 Add down_timeout and change ACPI to use it
ACPI currently emulates a timeout for semaphores with calls to
down_trylock and sleep.  This produces horrible behaviour in terms of
fairness and excessive wakeups.  Now that we have a unified semaphore
implementation, adding a real down_trylock is almost trivial.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-17 10:42:46 -04:00
Matthew Wilcox
f06d968658 Introduce down_killable()
down_killable() is the functional counterpart of mutex_lock_killable.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2008-04-17 10:42:40 -04:00
Matthew Wilcox
64ac24e738 Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 10:42:34 -04:00