Commit Graph

9845 Commits

Author SHA1 Message Date
Peter Zijlstra
8a49542c05 perf_events: Fix races in group composition
Group siblings don't pin each-other or the parent, so when we destroy
events we must make sure to clean up all cross referencing pointers.

In particular, for destruction of a group leader we must be able to
find all its siblings and remove their reference to it.

This means that detaching an event from its context must not detach it
from the group, otherwise we can end up failing to clear all pointers.

Solve this by clearly separating the attachment to a context and
attachment to a group, and keep the group composed until we destroy
the events.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 08:46:09 +02:00
Peter Zijlstra
ac9721f3f5 perf_events: Fix races and clean up perf_event and perf_mmap_data interaction
In order to move toward separate buffer objects, rework the whole
perf_mmap_data construct to be a more self-sufficient entity, one
with its own lifetime rules.

This greatly sanitizes the whole output redirection code, which
was riddled with bugs and races.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 08:46:08 +02:00
Amit K. Arora
54e88fad22 sched: Make sure timers have migrated before killing the migration_thread
Problem: In a stress test where some heavy tests were running along with
regular CPU offlining and onlining, a hang was observed. The system seems
to be hung at a point where migration_call() tries to kill the
migration_thread of the dying CPU, which just got moved to the current
CPU. This migration thread does not get a chance to run (and die) since
rt_throttled is set to 1 on current, and it doesn't get cleared as the
hrtimer which is supposed to reset the rt bandwidth
(sched_rt_period_timer) is tied to the CPU which we just marked dead!

Solution: This patch pushes the killing of migration thread to
"CPU_POST_DEAD" event. By then all the timers (including
sched_rt_period_timer) should have got migrated (along with other
callbacks).

Signed-off-by: Amit Arora <aarora@in.ibm.com>
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20100525132346.GA14986@amitarora.in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-31 08:37:44 +02:00
Linus Torvalds
fa7eadab4b Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  mutex: Fix optimistic spinning vs. BKL
2010-05-30 12:35:15 -07:00
Linus Torvalds
bc7d352c5e Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tui: Fix last use_browser problem related to .perfconfig
  perf symbols: Add the build id cache to the vmlinux path
  perf tui: Reset use_browser if stdout is not a tty
  ring-buffer: Move zeroing out excess in page to ring buffer code
  ring-buffer: Reset "real_end" when page is filled
2010-05-30 12:35:01 -07:00
Rafael J. Wysocki
e9a5f426b8 CPU: Avoid using unititialized error variable in disable_nonboot_cpus()
If there's only one CPU online when disable_nonboot_cpus() is called,
the error variable will not be initialized and that may lead to
erroneous behavior.  Fix this issue by initializing error in
disable_nonboot_cpus() as appropriate.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-30 09:06:00 -07:00
Linus Torvalds
35926ff5fb Revert "cpusets: randomize node rotor used in cpuset_mem_spread_node()"
This reverts commit 0ac0c0d0f8, which
caused cross-architecture build problems for all the wrong reasons.
IA64 already added its own version of __node_random(), but the fact is,
there is nothing architectural about the function, and the original
commit was just badly done. Revert it, since no fix is forthcoming.

Requested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-30 09:00:03 -07:00
Linus Torvalds
b612a05537 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: clean up on forwarded aborted mds request
  ceph: fix leak of osd authorizer
  ceph: close out mds, osd connections before stopping auth
  ceph: make lease code DN specific
  fs/ceph: Use ERR_CAST
  ceph: renew auth tickets before they expire
  ceph: do not resend mon requests on auth ticket renewal
  ceph: removed duplicated #includes
  ceph: avoid possible null dereference
  ceph: make mds requests killable, not interruptible
  sched: add wait_for_completion_killable_timeout
2010-05-30 08:56:39 -07:00
Sage Weil
0aa12fb439 sched: add wait_for_completion_killable_timeout
Add missing _killable_timeout variant for wait_for_completion that will
return when a timeout expires or the task is killed.

CC: Ingo Molnar <mingo@elte.hu>
CC: Andreas Herrmann <andreas.herrmann3@amd.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Sage Weil <sage@newdream.net>
2010-05-29 09:12:30 -07:00
Linus Torvalds
29d03fa12b Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  posix_timer: Fix error path in timer_create
  hrtimer: Avoid double seqlock
  timers: Move local variable into else section
  timers: Fix slack calculation really
2010-05-28 10:16:27 -07:00
Al Viro
ea635c64e0 Fix racy use of anon_inode_getfd() in perf_event.c
once anon_inode_getfd() is called, you can't expect *anything* about
struct file that descriptor points to - another thread might be doing
whatever it likes with descriptor table at that point.

Cc: stable <stable@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:03:08 -04:00
Linus Torvalds
c5617b200a Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (61 commits)
  tracing: Add __used annotation to event variable
  perf, trace: Fix !x86 build bug
  perf report: Support multiple events on the TUI
  perf annotate: Fix up usage of the build id cache
  x86/mmiotrace: Remove redundant instruction prefix checks
  perf annotate: Add TUI interface
  perf tui: Remove annotate from popup menu after failure
  perf report: Don't start the TUI if -D is used
  perf: Fix getline undeclared
  perf: Optimize perf_tp_event_match()
  perf: Remove more code from the fastpath
  perf: Optimize the !vmalloc backed buffer
  perf: Optimize perf_output_copy()
  perf: Fix wakeup storm for RO mmap()s
  perf-record: Share per-cpu buffers
  perf-record: Remove -M
  perf: Ensure that IOC_OUTPUT isn't used to create multi-writer buffers
  perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events
  perf, trace: Optimize tracepoints by removing IRQ-disable from perf/tracepoint interaction
  perf tui: Allow disabling the TUI on a per command basis in ~/.perfconfig
  ...
2010-05-27 15:23:47 -07:00
Andrey Vagin
45e0fffc8a posix_timer: Fix error path in timer_create
Move CLOCK_DISPATCH(which_clock, timer_create, (new_timer)) after all
posible EFAULT erros.

*_timer_create may allocate/get resources.
(for example posix_cpu_timer_create does get_task_struct)

[ tglx: fold the remove crappy comment patch into this ]

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: <stable@kernel.org>
Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-27 22:38:15 +02:00
Linus Torvalds
00b9b0af58 Avoid warning when CPU hotplug isn't enabled
Commit e9fb7631eb ("cpu-hotplug: introduce cpu_notify(),
__cpu_notify(), cpu_notify_nofail()") also introduced this annoying
warning:

  kernel/cpu.c:157: warning: 'cpu_notify_nofail' defined but not used

when CONFIG_HOTPLUG_CPU wasn't set.

So move that helper inside the #ifdef CONFIG_HOTPLUG_CPU region, and
simplify it while at it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 10:32:08 -07:00
Lee Schermerhorn
3dd6b5fb43 numa: in-kernel profiling: use cpu_to_mem() for per cpu allocations
In kernel profiling requires that we be able to allocate "local" memory
for each cpu.  Use "cpu_to_mem()" instead of "cpu_to_node()" to support
memoryless nodes.

Depends on the "numa_mem_id()" patch.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:57 -07:00
Anton Blanchard
5b530fc183 panic: call console_verbose() in panic
Most distros turn the console verbosity down and that means a backtrace
after a panic never makes it to the console.  I assume we haven't seen
this because a panic is often preceeded by an oops which will have called
console_verbose.  There are however a lot of places we call panic
directly, and they are broken.

Use console_verbose like we do in the oops path to ensure a directly
called panic will print a backtrace.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:53 -07:00
Oleg Nesterov
f106eee100 pids: fix fork_idle() to setup ->pids correctly
copy_process(pid => &init_struct_pid) doesn't do attach_pid/etc.

It shouldn't, but this means that the idle threads run with the wrong
pids copied from the caller's task_struct. In x86 case the caller is
either kernel_init() thread or keventd.

In particular, this means that after the series of cpu_up/cpu_down an
idle thread (which never exits) can run with .pid pointing to nowhere.

Change fork_idle() to initialize idle->pids[] correctly. We only set
.pid = &init_struct_pid but do not add .node to list, INIT_TASK() does
the same for the boot-cpu idle thread (swapper).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Mathias Krause <Mathias.Krause@secunet.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:52 -07:00
Hedi Berriche
72680a191b pids: increase pid_max based on num_possible_cpus
On a system with a substantial number of processors, the early default
pid_max of 32k will not be enough.  A system with 1664 CPU's, there are
25163 processes started before the login prompt.  It's estimated that with
2048 CPU's we will pass the 32k limit.  With 4096, we'll reach that limit
very early during the boot cycle, and processes would stall waiting for an
available pid.

This patch increases the early maximum number of pids available, and
increases the minimum number of pids that can be set during runtime.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Hedi Berriche <hedi@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: John Stoffel <john@stoffel.org>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:51 -07:00
Lai Jiangshan
79a6cdeb7e cpuhotplug: do not need cpu_hotplug_begin() when CONFIG_HOTPLUG_CPU=n
Since when CONFIG_HOTPLUG_CPU=n, get_online_cpus() do nothing, so we don't
need cpu_hotplug_begin() either.

This patch moves cpu_hotplug_begin()/cpu_hotplug_done() into the code
block of CONFIG_HOTPLUG_CPU=y.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Gautham R Shenoy <ego@in.ibm.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>
2010-05-27 09:12:48 -07:00
Akinobu Mita
80b5184cc5 kernel/: convert cpu notifier to return encapsulate errno value
By the previous modification, the cpu notifier can return encapsulate
errno value.  This converts the cpu notifiers for kernel/*.c

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:48 -07:00
Akinobu Mita
e6bde73b07 cpu-hotplug: return better errno on cpu hotplug failure
Currently, onlining or offlining a CPU failure by one of the cpu notifiers
error always cause -EINVAL error.  (i.e.  writing 0 or 1 to
/sys/devices/system/cpu/cpuX/online gets EINVAL)

To get better error reporting rather than always getting -EINVAL, This
changes cpu_notify() to return -errno value with notifier_to_errno() and
fix the callers.  Now that cpu notifiers can return encapsulate errno
value.

Currently, all cpu hotplug notifiers return NOTIFY_OK, NOTIFY_BAD, or
NOTIFY_DONE.  So cpu_notify() can returns 0 or -EPERM with this change for
now.

(notifier_to_errno(NOTIFY_OK) == 0, notifier_to_errno(NOTIFY_DONE) == 0,
notifier_to_errno(NOTIFY_BAD) == -EPERM)

Forthcoming patches convert several cpu notifiers to return encapsulate
errno value with notifier_from_errno().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:47 -07:00
Akinobu Mita
e9fb7631eb cpu-hotplug: introduce cpu_notify(), __cpu_notify(), cpu_notify_nofail()
No functional change.  These are just wrappers of
raw_cpu_notifier_call_chain.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:47 -07:00
Oleg Nesterov
b3ac022cb9 proc: turn signal_struct->count into "int nr_threads"
No functional changes, just s/atomic_t count/int nr_threads/.

With the recent changes this counter has a single user, get_nr_threads()
And, none of its callers need the really accurate number of threads, not
to mention each caller obviously races with fork/exit.  It is only used to
report this value to the user-space, except first_tid() uses it to avoid
the unnecessary while_each_thread() loop in the unlikely case.

It is a bit sad we need a word in struct signal_struct for this, perhaps
we can change get_nr_threads() to approximate the number of threads using
signal->live and kill ->nr_threads later.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:47 -07:00
Oleg Nesterov
5089a97680 proc_sched_show_task(): use get_nr_threads()
Trivial, use get_nr_threads() helper to read signal->count which we are
going to change.

Like other callers, proc_sched_show_task() doesn't need the exactly
precise nr_threads.

David said:

: Note that get_nr_threads() isn't completely equivalent (it can return 0
: where proc_sched_show_task() will display a 1).  But I don't think this
: should be a problem.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:47 -07:00
Oleg Nesterov
6e1be45aa6 check_unshare_flags: kill the bogus CLONE_SIGHAND/sig->count check
check_unshare_flags(CLONE_SIGHAND) adds CLONE_THREAD to *flags_ptr if the
task is multithreaded to ensure unshare_thread() will fail.

Not only this is a bit strange way to return the error, this is absolutely
meaningless.  If signal->count > 1 then sighand->count must be also > 1,
and unshare_sighand() will fail anyway.

In fact, all CLONE_THREAD/SIGHAND/VM checks inside sys_unshare() do not
look right.  Fortunately this code doesn't really work anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:47 -07:00
Oleg Nesterov
97101eb41d exit: move taskstats_tgid_free() from __exit_signal() to free_signal_struct()
Move taskstats_tgid_free() from __exit_signal() to free_signal_struct().

This way signal->stats never points to nowhere and we can read ->stats
lockless.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
a705be6b5e kill the obsolete thread_group_cputime_free() helper
Kill the empty thread_group_cputime_free() helper.  It was needed to free
the per-cpu data which we no longer have.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
d40e48e02f exit: __exit_signal: use thread_group_leader() consistently
Cleanup:

- Add the boolean, group_dead = thread_group_leader(), for clarity.

- Do not test/set sig == NULL to detect the all-dead case, use this
  boolean.

- Pass this boolen to __unhash_process() and use it instead of another
  thread_group_leader() call which needs ->group_leader.

  This can be considered as microoptimization, but hopefully this also
  allows us do do other cleanups later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
b7b8ff6373 signals: kill the awful task_rq_unlock_wait() hack
Now that task->signal can't go away we can revert the horrible hack added
by ad474caca3 ("fix for
account_group_exec_runtime(), make sure ->signal can't be freed under
rq->lock").

And we can do more cleanups sched_stats.h/posix-cpu-timers.c later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
4ada856fb0 signals: clear signal->tty when the last thread exits
When the last thread exits signal->tty is freed, but the pointer is not
cleared and points to nowhere.

This is OK.  Nobody should use signal->tty lockless, and it is no longer
possible to take ->siglock.  However this looks wrong even if correct, and
the nice OOPS is better than subtle and hard to find bugs.

Change __exit_signal() to clear signal->tty under ->siglock.

Note: __exit_signal() needs more cleanups.  It should not check "sig !=
NULL" to detect the all-dead case and we have the same issues with
signal->stats.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
ea6d290ca3 signals: make task_struct->signal immutable/refcountable
We have a lot of problems with accessing task_struct->signal, it can
"disappear" at any moment.  Even current can't use its ->signal safely
after exit_notify().  ->siglock helps, but it is not convenient, not
always possible, and sometimes it makes sense to use task->signal even
after this task has already dead.

This patch adds the reference counter, sigcnt, into signal_struct.  This
reference is owned by task_struct and it is dropped in
__put_task_struct().  Perhaps it makes sense to export
get/put_signal_struct() later, but currently I don't see the immediate
reason.

Rename __cleanup_signal() to free_signal_struct() and unexport it.  With
the previous changes it does nothing except kmem_cache_free().

Change __exit_signal() to not clear/free ->signal, it will be freed when
the last reference to any thread in the thread group goes away.

Note:
	- when the last thead exits signal->tty can point to nowhere, see
	  the next patch.

	- with or without this patch signal_struct->count should go away,
	  or at least it should be "int nr_threads" for fs/proc. This will
	  be addressed later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
4dec2a91fd fork/exit: move tty_kref_put() outside of __cleanup_signal()
tty_kref_put() has two callsites in copy_process() paths,

	1. if copy_process() suceeds it is called before we copy
	   signal->tty from parent

	2. otherwise it is called from __cleanup_signal() under
	   bad_fork_cleanup_signal: label

In both cases tty_kref_put() is not right and unneeded because we don't
have the balancing tty_kref_get().  Fortunately, this is harmless because
this can only happen without CLONE_THREAD, and in this case signal->tty
must be NULL.

Remove tty_kref_put() from copy_process() and __cleanup_signal(), and
change another caller of __cleanup_signal(), __exit_signal(), to call
tty_kref_put() by hand.

I hope this change makes sense by itself, but it is also needed to make
->signal refcountable.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
d30fda3551 posix-cpu-timers: avoid "task->signal != NULL" checks
Preparation to make task->signal immutable, no functional changes.

posix-cpu-timers.c checks task->signal != NULL to ensure this task is
alive and didn't pass __exit_signal().  This is correct but we are going
to change the lifetime rules for ->signal and never reset this pointer.

Change the code to check ->sighand instead, it doesn't matter which
pointer we check under tasklist, they both are cleared simultaneously.

As Roland pointed out, some of these changes are not strictly needed and
probably it makes sense to revert them later, when ->signal will be pinned
to task_struct.  But this patch tries to ensure the subsequent changes in
fork/exit can't make any visible impact on posix cpu timers.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Tony Luck <tony.luck@intel.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>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
4a59994297 exit: avoid sig->count in __exit_signal() to detect the group-dead case
Change __exit_signal() to check thread_group_leader() instead of
atomic_dec_and_test(&sig->count).  This must be equivalent, the group
leader must be released only after all other threads have exited and
passed __exit_signal().

Henceforth sig->count is not actually used, except in fs/proc for
get_nr_threads/etc.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
d344193a05 exit: avoid sig->count in de_thread/__exit_signal synchronization
de_thread() and __exit_signal() use signal_struct->count/notify_count for
synchronization.  We can simplify the code and use ->notify_count only.
Instead of comparing these two counters, we can change de_thread() to set
->notify_count = nr_of_sub_threads, then change __exit_signal() to
dec-and-test this counter and notify group_exit_task.

Note that __exit_signal() checks "notify_count > 0" just for symmetry with
exit_notify(), we could just check it is != 0.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
09faef11df exit: change zap_other_threads() to count sub-threads
Change zap_other_threads() to return the number of other sub-threads found
on ->thread_group list.

Other changes are cosmetic:

	- change the code to use while_each_thread() helper

	- remove the obsolete comment about SIGKILL/SIGSTOP

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:46 -07:00
Oleg Nesterov
9c33916844 exit: exit_notify() can trust signal->notify_count < 0
signal_struct->count in its current form must die.

- it has no reasons to be atomic_t

- it looks like a reference counter, but it is not

- otoh, we really need to make task->signal refcountable, just look at
  the extremely ugly task_rq_unlock_wait() called from __exit_signals().

- we should change the lifetime rules for task->signal, it should be
  pinned to task_struct.  We have a lot of code which can be simplified
  after that.

- it is not needed!  while the code is correct, any usage of this
  counter is artificial, except fs/proc uses it correctly to show the
  number of threads.

This series removes the usage of sig->count from exit pathes.

This patch:

Now that Veaceslav changed copy_signal() to use zalloc(), exit_notify()
can just check notify_count < 0 to ensure the execing sub-threads needs
the notification from us.  No need to do other checks, notify_count != 0
must always mean ->group_exit_task != NULL is waiting for us.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
04b1c384fb call_usermodehelper: UMH_WAIT_EXEC ignores kernel_thread() failure
UMH_WAIT_EXEC should report the error if kernel_thread() fails, like
UMH_WAIT_PROC does.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
d47419cd96 call_usermodehelper: simplify/fix UMH_NO_WAIT case
__call_usermodehelper(UMH_NO_WAIT) has 2 problems:

	- if kernel_thread() fails, call_usermodehelper_freeinfo()
	  is not called.

	- for unknown reason UMH_NO_WAIT has UMH_WAIT_PROC logic,
	  we spawn yet another thread which waits until the user
	  mode application exits.

Change the UMH_NO_WAIT code to use ____call_usermodehelper() instead of
wait_for_helper(), and do call_usermodehelper_freeinfo() unconditionally.
We can rely on CLONE_VFORK, do_fork(CLONE_VFORK) until the child exits or
execs.

With or without this patch UMH_NO_WAIT does not report the error if
kernel_thread() fails, this is correct since the caller doesn't wait for
result.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
7d64224217 wait_for_helper: SIGCHLD from user-space can lead to use-after-free
1. wait_for_helper() calls allow_signal(SIGCHLD) to ensure the child
   can't autoreap itself.

   However, this means that a spurious SIGCHILD from user-space can
   set TIF_SIGPENDING and:

   	- kernel_thread() or sys_wait4() can fail due to signal_pending()

   	- worse, wait4() can fail before ____call_usermodehelper() execs
   	  or exits. In this case the caller may kfree(subprocess_info)
   	  while the child still uses this memory.

   Change the code to use SIG_DFL instead of magic "(void __user *)2"
   set by allow_signal(). This means that SIGCHLD won't be delivered,
   yet the child won't autoreap itsefl.

   The problem is minor, only root can send a signal to this kthread.

2. If sys_wait4(&ret) fails it doesn't populate "ret", in this case
   wait_for_helper() reports a random value from uninitialized var.

   With this patch sys_wait4() should never fail, but still it makes
   sense to initialize ret = -ECHILD so that the caller can notice
   the problem.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
363da4022c call_usermodehelper: no need to unblock signals
____call_usermodehelper() correctly calls flush_signal_handlers() to set
SIG_DFL, but sigemptyset(->blocked) and recalc_sigpending() are not
needed.

This kthread was forked by workqueue thread, all signals must be unblocked
and ignored, no pending signal is possible.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
c70a626d3e umh: creds: kill subprocess_info->cred logic
Now that nobody ever changes subprocess_info->cred we can kill this member
and related code.  ____call_usermodehelper() always runs in the context of
freshly forked kernel thread, it has the proper ->cred copied from its
parent kthread, keventd.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Oleg Nesterov
685bfd2c48 umh: creds: convert call_usermodehelper_keys() to use subprocess_info->init()
call_usermodehelper_keys() uses call_usermodehelper_setkeys() to change
subprocess_info->cred in advance.  Now that we have info->init() we can
change this code to set tgcred->session_keyring in context of execing
kernel thread.

Note: since currently call_usermodehelper_keys() is never called with
UMH_NO_WAIT, call_usermodehelper_keys()->key_get() and umh_keys_cleanup()
are not really needed, we could rely on install_session_keyring_to_cred()
which does key_get() on success.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:45 -07:00
Neil Horman
898b374af6 exec: replace call_usermodehelper_pipe with use of umh init function and resolve limit
The first patch in this series introduced an init function to the
call_usermodehelper api so that processes could be customized by caller.
This patch takes advantage of that fact, by customizing the helper in
do_coredump to create the pipe and set its core limit to one (for our
recusrsion check).  This lets us clean up the previous uglyness in the
usermodehelper internals and factor call_usermodehelper out entirely.
While I'm at it, we can also modify the helper setup to look for a core
limit value of 1 rather than zero for our recursion check

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Neil Horman
a06a4dc3a0 kmod: add init function to usermodehelper
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works.  We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.

We fixed those by improving our recursion checks.  The new check basically
refuses to fork a process if its core limit is zero, which works well.

Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern.  They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'.  I did this by design, and
think thats the right way to do things.

But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it.  The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one.  That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection.  This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.

So I've come up with this.  What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process.  This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code.  In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1.  This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.

This patch:

Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.

The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec.  Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process

Also, use this patch to cleanup the cleanup function.  It currently takes
an argp and envp pointer for freeing, which is ugly.  Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Oleg Nesterov
065add3941 signals: check_kill_permission(): don't check creds if same_thread_group()
Andrew Tridgell reports that aio_read(SIGEV_SIGNAL) can fail if the
notification from the helper thread races with setresuid(), see
http://samba.org/~tridge/junkcode/aio_uid.c

This happens because check_kill_permission() doesn't permit sending a
signal to the task with the different cred->xids.  But there is not any
security reason to check ->cred's when the task sends a signal (private or
group-wide) to its sub-thread.  Whatever we do, any thread can bypass all
security checks and send SIGKILL to all threads, or it can block a signal
SIG and do kill(gettid(), SIG) to deliver this signal to another
sub-thread.  Not to mention that CLONE_THREAD implies CLONE_VM.

Change check_kill_permission() to avoid the credentials check when the
sender and the target are from the same thread group.

Also, move "cred = current_cred()" down to avoid calling get_current()
twice.

Note: David Howells pointed out we could relax this even more, the
CLONE_SIGHAND (without CLONE_THREAD) case probably does not need
these checks too.

Roland said:
: The glibc (libpthread) that does set*id across threads has
: been in use for a while (2.3.4?), probably in distro's using kernels as old
: or older than any active -stable streams.  In the race in question, this
: kernel bug is breaking valid POSIX application expectations.

Reported-by: Andrew Tridgell <tridge@samba.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: <stable@kernel.org>		[all kernel versions]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Oleg Nesterov
e0129ef91e ptrace: PTRACE_GETFDPIC: fix the unsafe usage of child->mm
Now that Mike Frysinger unified the FDPIC ptrace code, we can fix the
unsafe usage of child->mm in ptrace_request(PTRACE_GETFDPIC).

We have the reference to task_struct, and ptrace_check_attach() verified
the tracee is stopped.  But nothing can protect from SIGKILL after that,
we must not assume child->mm != NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Greg Ungerer <gerg@snapgear.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Mike Frysinger
9c1a125921 ptrace: unify FDPIC implementations
The Blackfin/FRV/SuperH guys all have the same exact FDPIC ptrace code in
their arch handlers (since they were probably copied & pasted).  Since
these ptrace interfaces are an arch independent aspect of the FDPIC code,
unify them in the common ptrace code so new FDPIC ports don't need to copy
and paste this fundamental stuff yet again.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Jack Steiner
0ac0c0d0f8 cpusets: randomize node rotor used in cpuset_mem_spread_node()
Some workloads that create a large number of small files tend to assign
too many pages to node 0 (multi-node systems).  Part of the reason is that
the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at
node 0 for newly created tasks.

This patch changes the rotor to be initialized to a random node number of
the cpuset.

[akpm@linux-foundation.org: fix layout]
[Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Jack Steiner
6adef3ebe5 cpusets: new round-robin rotor for SLAB allocations
We have observed several workloads running on multi-node systems where
memory is assigned unevenly across the nodes in the system.  There are
numerous reasons for this but one is the round-robin rotor in
cpuset_mem_spread_node().

For example, a simple test that writes a multi-page file will allocate
pages on nodes 0 2 4 6 ...  Odd nodes are skipped.  (Sometimes it
allocates on odd nodes & skips even nodes).

An example is shown below.  The program "lfile" writes a file consisting
of 10 pages.  The program then mmaps the file & uses get_mempolicy(...,
MPOL_F_NODE) to determine the nodes where the file pages were allocated.
The output is shown below:

	# ./lfile
	 allocated on nodes: 2 4 6 0 1 2 6 0 2

There is a single rotor that is used for allocating both file pages & slab
pages.  Writing the file allocates both a data page & a slab page
(buffer_head).  This advances the RR rotor 2 nodes for each page
allocated.

A quick confirmation seems to confirm this is the cause of the uneven
allocation:

	# echo 0 >/dev/cpuset/memory_spread_slab
	# ./lfile
	 allocated on nodes: 6 7 8 9 0 1 2 3 4 5

This patch introduces a second rotor that is used for slab allocations.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Kirill A. Shutemov
907860ed38 cgroups: make cftype.unregister_event() void-returning
Since we are unable to handle an error returned by
cftype.unregister_event() properly, let's make the callback
void-returning.

mem_cgroup_unregister_event() has been rewritten to be a "never fail"
function.  On mem_cgroup_usage_register_event() we save old buffer for
thresholds array and reuse it in mem_cgroup_usage_unregister_event() to
avoid allocation.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Stanislaw Gruszka
174bd1994e hrtimer: Avoid double seqlock
hrtimer_get_softirq_time() has it's own xtime lock protection, so it's
safe to use plain __current_kernel_time() and avoid the double seqlock
loop.

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
LKML-Reference: <20100525214912.GA1934@r2bh72.net.upc.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-26 16:15:37 +02:00
Thomas Gleixner
2abfb9e1d4 timers: Move local variable into else section
Fix nit-picking coding style detail.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-26 16:07:13 +02:00
Linus Torvalds
b1cdc4670b 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: (63 commits)
  drivers/net/usb/asix.c: Fix pointer cast.
  be2net: Bug fix to avoid disabling bottom half during firmware upgrade.
  proc_dointvec: write a single value
  hso: add support for new products
  Phonet: fix potential use-after-free in pep_sock_close()
  ath9k: remove VEOL support for ad-hoc
  ath9k: change beacon allocation to prefer the first beacon slot
  sock.h: fix kernel-doc warning
  cls_cgroup: Fix build error when built-in
  macvlan: do proper cleanup in macvlan_common_newlink() V2
  be2net: Bug fix in init code in probe
  net/dccp: expansion of error code size
  ath9k: Fix rx of mcast/bcast frames in PS mode with auto sleep
  wireless: fix sta_info.h kernel-doc warnings
  wireless: fix mac80211.h kernel-doc warnings
  iwlwifi: testing the wrong variable in iwl_add_bssid_station()
  ath9k_htc: rare leak in ath9k_hif_usb_alloc_tx_urbs()
  ath9k_htc: dereferencing before check in hif_usb_tx_cb()
  rt2x00: Fix rt2800usb TX descriptor writing.
  rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions.
  ...
2010-05-25 16:59:51 -07:00
Linus Torvalds
218ce73514 Revert "module: drop the lock while waiting for module to complete initialization."
This reverts commit 480b02df3a, since
Rafael reports that it causes occasional kernel paging request faults in
load_module().

Dropping the module lock and re-taking it deep in the call-chain is
definitely not the right thing to do.  That just turns the mutex from a
lock into a "random non-locking data structure" that doesn't actually
protect what it's supposed to protect.

Requested-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Brandon Philips <brandon@ifup.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 16:48:30 -07:00
J. R. Okajima
563b046710 proc_dointvec: write a single value
The commit 00b7c3395a
"sysctl: refactor integer handling proc code"
modified the behaviour of writing to /proc.
Before the commit, write("1\n") to /proc/sys/kernel/printk succeeded. But
now it returns EINVAL.

This commit supports writing a single value to a multi-valued entry.

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Reviewed-and-tested-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-25 16:10:14 -07:00
Thomas Gleixner
8e63d7795e timers: Fix slack calculation really
commit f00e047ef (timers: Fix slack calculation for expired timers)
fixed the issue of slack on expired timers only partially. Linus
noticed that jiffies is volatile so it is reloaded twice, which
generates bad code.

But its worse. This can defeat the time_after() check if jiffies are
incremented between time_after() and the slack calculation.

Fix it by reading jiffies into a local variable, which prevents the
compiler from loading it twice. While at it make the > -1 check into
>= 0 which is easier to read.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 21:07:48 +02:00
Steven Rostedt
2711ca237a ring-buffer: Move zeroing out excess in page to ring buffer code
Currently the trace splice code zeros out the excess bytes in the page before
sending it off to userspace.

This is to make sure userspace is not getting anything it should not be
when reading the pages, because the excess data was never initialized
to zero before writing (for perfomance reasons).

But the splice code has no business in doing this work, it should be
done by the ring buffer. With the latest changes for recording lost
events, the splice code gets it wrong anyway.

Move the zeroing out of excess bytes into the ring buffer code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-25 11:57:26 -04:00
Steven Rostedt
b3230c8b44 ring-buffer: Reset "real_end" when page is filled
The code to store the "lost events" requires knowing the real end
of the page. Since the 'commit' includes the padding at the end of
a page a "real_end" variable was used to keep track of the end not
including the padding.

If events were lost, the reader can place the count of events in
the padded area if there is enough room.

The bug this patch fixes is that when we fill the page we do not
reset the real_end variable, and if the writer had wrapped a few
times, the real_end would be incorrect.

This patch simply resets the real_end if the page was filled.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-25 11:57:24 -04:00
Andy Shevchenko
69e4469a39 sysctl: don't use own implementation of hex_to_bin()
Remove own implementation of hex_to_bin().

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:05 -07:00
Wenji Huang
7d52669b14 module: remove duplicate declaration of __ksymtab_gpl_future
Minor cleanup on duplicate __{start/stop}__ksymtab_gpl_future.

Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:04 -07:00
Haicheng Li
4eaf3f6439 mem-hotplug: fix potential race while building zonelist for new populated zone
Add global mutex zonelists_mutex to fix the possible race:

     CPU0                                  CPU1                    CPU2
(1) zone->present_pages += online_pages;
(2)                                       build_all_zonelists();
(3)                                                               alloc_page();
(4)                                                               free_page();
(5) build_all_zonelists();
(6)   __build_all_zonelists();
(7)     zone->pageset = alloc_percpu();

In step (3,4), zone->pageset still points to boot_pageset, so bad
things may happen if 2+ nodes are in this state. Even if only 1 node
is accessing the boot_pageset, (3) may still consume too much memory
to fail the memory allocations in step (7).

Besides, atomic operation ensures alloc_percpu() in step (7) will never fail
since there is a new fresh memory block added in step(6).

[haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:02 -07:00
Haicheng Li
1f522509c7 mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset
For each new populated zone of hotadded node, need to update its pagesets
with dynamically allocated per_cpu_pageset struct for all possible CPUs:

    1) Detach zone->pageset from the shared boot_pageset
       at end of __build_all_zonelists().

    2) Use mutex to protect zone->pageset when it's still
       shared in onlined_pages()

Otherwises, multiple zones of different nodes would share same boot strapping
boot_pageset for same CPU, which will finally cause below kernel panic:

  ------------[ cut here ]------------
  kernel BUG at mm/page_alloc.c:1239!
  invalid opcode: 0000 [#1] SMP
  ...
  Call Trace:
   [<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0
   [<ffffffff81162e67>] alloc_pages_current+0x87/0xd0
   [<ffffffff81128407>] __page_cache_alloc+0x67/0x70
   [<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260
   [<ffffffff81132751>] ra_submit+0x21/0x30
   [<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0
   [<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0
   [<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670
   [<ffffffff81266cfa>] nfs_file_read+0xca/0x130
   [<ffffffff8117b20a>] do_sync_read+0xfa/0x140
   [<ffffffff8117bf75>] vfs_read+0xb5/0x1a0
   [<ffffffff8117c151>] sys_read+0x51/0x80
   [<ffffffff8103c032>] system_call_fastpath+0x16/0x1b
  RIP  [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900
   RSP <ffff88000d1e78a8>
  ---[ end trace 4bda28328b9990db ]

[akpm@linux-foundation.org: merge fix]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:01 -07:00
minskey guo
cf23422b9d cpu/mem hotplug: enable CPUs online before local memory online
Enable users to online CPUs even if the CPUs belongs to a numa node which
doesn't have onlined local memory.

The zonlists(pg_data_t.node_zonelists[]) of a numa node are created either
in system boot/init period, or at the time of local memory online.  For a
numa node without onlined local memory, its zonelists are not initialized
at present.  As a result, any memory allocation operations executed by
CPUs within this node will fail.  In fact, an out-of-memory error is
triggered when attempt to online CPUs before memory comes to online.

This patch tries to create zonelists for such numa nodes, so that the
memory allocation for this node can be fallback'ed to other nodes.

[akpm@linux-foundation.org: remove unneeded export]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: minskey guo<chaohong.guo@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:00 -07:00
Mel Gorman
5e77190580 mm: compaction: add a tunable that decides when memory should be compacted and when it should be reclaimed
The kernel applies some heuristics when deciding if memory should be
compacted or reclaimed to satisfy a high-order allocation.  One of these
is based on the fragmentation.  If the index is below 500, memory will not
be compacted.  This choice is arbitrary and not based on data.  To help
optimise the system and set a sensible default for this value, this patch
adds a sysctl extfrag_threshold.  The kernel will only compact memory if
the fragmentation index is above the extfrag_threshold.

[randy.dunlap@oracle.com: Fix build errors when proc fs is not configured]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.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>
2010-05-25 08:06:59 -07:00
Mel Gorman
76ab0f530e mm: compaction: add /proc trigger for memory compaction
Add a proc file /proc/sys/vm/compact_memory.  When an arbitrary value is
written to the file, all zones are compacted.  The expected user of such a
trigger is a job scheduler that prepares the system before the target
application runs.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:59 -07:00
Miao Xie
c0ff7453bb cpuset,mm: fix no node to alloc memory when changing cpuset's mems
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Miao Xie
708c1bbc9d mempolicy: restructure rebinding-mempolicy functions
Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1].  It happens only on the kernel that do not do
atomic nodemask_t stores.  (MAX_NUMNODES > BITS_PER_LONG)

But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores.  The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory.  The reason is like this:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

I can use the attached program reproduce it by the following step:

# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
   <nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh

several hours later, oom will happen though there is a lot of free memory.

This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits).  So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.

This patch:

In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.

So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes.  The 2nd step: shrink the set of
the mempolicy's nodes.  It is used when there is no real lock to protect
the mempolicy in the read-side.  Otherwise we can do rebind work at once.

In order to implement it, we define

	enum mpol_rebind_step {
		MPOL_REBIND_ONCE,
		MPOL_REBIND_STEP1,
		MPOL_REBIND_STEP2,
		MPOL_REBIND_NSTEP,
	};

If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions.  Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.

Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed.  If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock.  So we defined the
following flag to identify it:

#define MPOL_F_REBINDING (1 << 2)

The new functions will be used in the next patch.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Peter Zijlstra
87f44bbc24 perf, trace: Fix !x86 build bug
Patch b7e2ecef92 (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.

The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.

Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-25 11:28:49 +02:00
Jeff Chua
f00e047efd timers: Fix slack calculation for expired timers
commit 3bbb9ec946 (timers: Introduce the concept of timer slack for
legacy timers) does not take the case into account when the timer is
already expired. This broke wireless drivers.

The solution is not to apply slack to already expired timers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
2010-05-24 12:10:23 +02:00
Thomas Gleixner
bd45b7a385 timekeeping: Fix timezone update
commit 64ce4c2f (time: Clean up warp_clock()) breaks the timezone
update in a very subtle way. To avoid the direct access to timekeeping
internals it adds the timezone delta to the current time with
timespec_add_safe(). This works nicely when the timezone delta is > 0.
If timezone delta is < 0 then the wrap check in timespec_add_safe()
triggers and timespec_add_safe() returns TIME_MAX and screws up
timekeeping completely. 

The comment above timespec_add_safe() says:
    It's assumed that both values are valid (>= 0)

Add the timezone seconds adjustment directly.

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-24 11:50:38 +02:00
Linus Torvalds
6109e2ce26 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (36 commits)
  PCI: hotplug: pciehp: Removed check for hotplug of display devices
  PCI: read memory ranges out of Broadcom CNB20LE host bridge
  PCI: Allow manual resource allocation for PCI hotplug bridges
  x86/PCI: make ACPI MCFG reserved error messages ACPI specific
  PCI hotplug: Use kmemdup
  PM/PCI: Update PCI power management documentation
  PCI: output FW warning in pci_read/write_vpd
  PCI: fix typos pci_device_dis/enable to pci_dis/enable_device in comments
  PCI quirks: disable msi on AMD rs4xx internal gfx bridges
  PCI: Disable MSI for MCP55 on P5N32-E SLI
  x86/PCI: irq and pci_ids patch for additional Intel Cougar Point DeviceIDs
  PCI: aerdrv: trivial cleanup for aerdrv_core.c
  PCI: aerdrv: trivial cleanup for aerdrv.c
  PCI: aerdrv: introduce default_downstream_reset_link
  PCI: aerdrv: rework find_aer_service
  PCI: aerdrv: remove is_downstream
  PCI: aerdrv: remove magical ROOT_ERR_STATUS_MASKS
  PCI: aerdrv: redefine PCI_ERR_ROOT_*_SRC
  PCI: aerdrv: rework do_recovery
  PCI: aerdrv: rework get_e_source()
  ...
2010-05-21 18:58:52 -07:00
Linus Torvalds
0961d6581c Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6:
  intel-iommu: Set a more specific taint flag for invalid BIOS DMAR tables
  intel-iommu: Combine the BIOS DMAR table warning messages
  panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I')
  panic: Allow warnings to set different taint flags
  intel-iommu: intel_iommu_map_range failed at very end of address space
  intel-iommu: errors with smaller iommu widths
  intel-iommu: Fix boot inside 64bit virtualbox with io-apic disabled
  intel-iommu: use physfn to search drhd for VF
  intel-iommu: Print out iommu seq_id
  intel-iommu: Don't complain that ACPI_DMAR_SCOPE_TYPE_IOAPIC is not supported
  intel-iommu: Avoid global flushes with caching mode.
  intel-iommu: Use correct domain ID when caching mode is enabled
  intel-iommu mistakenly uses offset_pfn when caching mode is enabled
  intel-iommu: use for_each_set_bit()
  intel-iommu: Fix section mismatch dmar_ir_support() uses dmar_tbl.
2010-05-21 17:25:01 -07:00
Linus Torvalds
a8251096b4 Merge branch 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: drop the lock while waiting for module to complete initialization.
  MODULE_DEVICE_TABLE(isapnp, ...) does nothing
  hisax_fcpcipnp: fix broken isapnp device table.
  isapnp: move definitions to mod_devicetable.h so file2alias can reach them.
2010-05-21 17:15:44 -07:00
Linus Torvalds
6e80e8ed5e Merge branch 'for-2.6.35' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.35' of git://git.kernel.dk/linux-2.6-block: (86 commits)
  pipe: set lower and upper limit on max pages in the pipe page array
  pipe: add support for shrinking and growing pipes
  drbd: This is now equivalent to drbd release 8.3.8rc1
  drbd: Do not free p_uuid early, this is done in the exit code of the receiver
  drbd: Null pointer deref fix to the large "multi bio rewrite"
  drbd: Fix: Do not detach, if a bio with a barrier fails
  drbd: Ensure to not trigger late-new-UUID creation multiple times
  drbd: Do not Oops when C_STANDALONE when uuid gets generated
  writeback: fix mixed up arguments to bdi_start_writeback()
  writeback: fix problem with !CONFIG_BLOCK compilation
  block: improve automatic native capacity unlocking
  block: use struct parsed_partitions *state universally in partition check code
  block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()
  block: restart partition scan after resizing a device
  buffer: make invalidate_bdev() drain all percpu LRU add caches
  block: remove all rcu head initializations
  writeback: fixups for !dirty_writeback_centisecs
  writeback: bdi_writeback_task() must set task state before calling schedule()
  writeback: ensure that WB_SYNC_NONE writeback with sb pinned is sync
  drivers/block/drbd: Use kzalloc
  ...
2010-05-21 15:25:33 -07:00
Randy Dunlap
0fc377bd64 sysctl: fix kernel-doc notation and typos
Fix kernel-doc warnings, kernel-doc special characters, and
typos in recent kernel/sysctl.c additions.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Amerigo Wang <amwang@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-21 15:23:12 -07:00
Linus Torvalds
2a8ba8f032 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (46 commits)
  random: simplify fips mode
  crypto: authenc - Fix cryptlen calculation
  crypto: talitos - add support for sha224
  crypto: talitos - add hash algorithms
  crypto: talitos - second prepare step for adding ahash algorithms
  crypto: talitos - prepare for adding ahash algorithms
  crypto: n2 - Add Niagara2 crypto driver
  crypto: skcipher - Add ablkcipher_walk interfaces
  crypto: testmgr - Add testing for async hashing and update/final
  crypto: tcrypt - Add speed tests for async hashing
  crypto: scatterwalk - Fix scatterwalk_done() test
  crypto: hifn_795x - Rename ablkcipher_walk to hifn_cipher_walk
  padata: Use get_online_cpus/put_online_cpus in padata_free
  padata: Add some code comments
  padata: Flush the padata queues actively
  padata: Use a timer to handle remaining objects in the reorder queues
  crypto: shash - Remove usage of CRYPTO_MINALIGN
  crypto: mv_cesa - Use resource_size
  crypto: omap - OMAP macros corrected
  padata: Use get_online_cpus/put_online_cpus
  ...

Fix up conflicts in arch/arm/mach-omap2/devices.c
2010-05-21 14:46:51 -07:00
Jens Axboe
ee9a3607fb Merge branch 'master' into for-2.6.35
Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:27:26 +02:00
Jens Axboe
b492e95be0 pipe: set lower and upper limit on max pages in the pipe page array
We need at least two to guarantee proper POSIX behaviour, so
never allow a smaller limit than that.

Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows
root to define a sane upper limit. Make it default to 16 times the
default size, which is 16 pages.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:12:52 +02:00
Jens Axboe
35f3d14dbb pipe: add support for shrinking and growing pipes
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21 21:12:40 +02:00
Linus Torvalds
ac3ee84c60 Merge branch 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  echi-dbgp: Add kernel debugger support for the usb debug port
  earlyprintk,vga,kdb: Fix \b and \r for earlyprintk=vga with kdb
  kgdboc: Add ekgdboc for early use of the kernel debugger
  x86,early dr regs,kgdb: Allow kernel debugger early dr register access
  x86,kgdb: Implement early hardware breakpoint debugging
  x86, kgdb, init: Add early and late debug states
  x86, kgdb: early trap init for early debug
2010-05-21 11:10:41 -07:00
Linus Torvalds
90b9a32d8f Merge branch 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
  kdb,debug_core: Allow the debug core to receive a panic notification
  MAINTAINERS: update kgdb, kdb, and debug_core info
  debug_core,kdb: Allow the debug core to process a recursive debug entry
  printk,kdb: capture printk() when in kdb shell
  kgdboc,kdb: Allow kdb to work on a non open console port
  kgdb: Add the ability to schedule a breakpoint via a tasklet
  mips,kgdb: kdb low level trap catch and stack trace
  powerpc,kgdb: Introduce low level trap catching
  x86,kgdb: Add low level debug hook
  kgdb: remove post_primary_code references
  kgdb,docs: Update the kgdb docs to include kdb
  kgdboc,keyboard: Keyboard driver for kdb with kgdb
  kgdb: gdb "monitor" -> kdb passthrough
  sparc,sunzilog: Add console polling support for sunzilog serial driver
  sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
  kgdb,8250,pl011: Return immediately from console poll
  kgdb: core changes to support kdb
  kdb: core for kgdb back end (2 of 2)
  kdb: core for kgdb back end (1 of 2)
  kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
  ...
2010-05-21 11:08:05 -07:00
Chris Wright
2c3c8bea60 sysfs: add struct file* to bin_attr callbacks
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
Peter Zijlstra
1704f47b50 lockdep: Add novalidate class for dev->mutex conversion
The conversion of device->sem to device->mutex resulted in lockdep
warnings. Create a novalidate class for now until the driver folks
come up with separate classes. That way we have at least the basic
mutex debugging coverage.

Add a checkpatch error so the usage is reserved for device->mutex.

[ tglx: checkpatch and compile fix for LOCKDEP=n ]

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:30 -07:00
NeilBrown
db1afffab0 kref: remove kref_set
Of the three uses of kref_set in the kernel:

 One really should be kref_put as the code is letting go of a
    reference,
 Two really should be kref_init because the kref is being
    initialised.

This suggests that making kref_set available encourages bad code.
So fix the three uses and remove kref_set completely.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:29 -07:00
Steven Rostedt
ff5f149b6a Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-7
Conflicts:
	include/linux/ftrace_event.h
	include/trace/ftrace.h
	kernel/trace/trace_event_perf.c
	kernel/trace/trace_kprobe.c
	kernel/trace/trace_syscalls.c

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-05-21 11:49:57 -04:00
Linus Torvalds
33cf23b0a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (182 commits)
  [SCSI] aacraid: add an ifdef'd device delete case instead of taking the device offline
  [SCSI] aacraid: prohibit access to array container space
  [SCSI] aacraid: add support for handling ATA pass-through commands.
  [SCSI] aacraid: expose physical devices for models with newer firmware
  [SCSI] aacraid: respond automatically to volumes added by config tool
  [SCSI] fcoe: fix fcoe module ref counting
  [SCSI] libfcoe: FIP Keep-Alive messages for VPorts are sent with incorrect port_id and wwn
  [SCSI] libfcoe: Fix incorrect MAC address clearing
  [SCSI] fcoe: fix a circular locking issue with rtnl and sysfs mutex
  [SCSI] libfc: Move the port_id into lport
  [SCSI] fcoe: move link speed checking into its own routine
  [SCSI] libfc: Remove extra pointer check
  [SCSI] libfc: Remove unused fc_get_host_port_type
  [SCSI] fcoe: fixes wrong error exit in fcoe_create
  [SCSI] libfc: set seq_id for incoming sequence
  [SCSI] qla2xxx: Updates to ISP82xx support.
  [SCSI] qla2xxx: Optionally disable target reset.
  [SCSI] qla2xxx: ensure flash operation and host reset via sg_reset are mutually exclusive
  [SCSI] qla2xxx: Silence bogus warning by gcc for wrap and did.
  [SCSI] qla2xxx: T10 DIF support added.
  ...
2010-05-21 07:19:18 -07:00
Peter Zijlstra
580d607cd6 perf: Optimize perf_tp_event_match()
Since we know tracepoints come from kernel context,
avoid conditionals that try and establish that very
fact.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.904944001@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:38:00 +02:00
Peter Zijlstra
a94ffaaf55 perf: Remove more code from the fastpath
Sanity checks cost instructions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.852926930@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:59 +02:00
Peter Zijlstra
3cafa9fbb5 perf: Optimize the !vmalloc backed buffer
Reduce code and data by using the knowledge that for
!PERF_USE_VMALLOC data_order is always 0.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.795019386@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:59 +02:00
Peter Zijlstra
5d967a8be6 perf: Optimize perf_output_copy()
Reduce the clutter in perf_output_copy() by keeping
an interator in perf_output_handle.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.742809176@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:59 +02:00
Peter Zijlstra
adb8e118f2 perf: Fix wakeup storm for RO mmap()s
RO mmap()s don't update the tail pointer, so
comparing against it for determining the written data
size doesn't really do any good.

Keep track of when we last did a wakeup, and compare
against that.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.684479310@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:58 +02:00
Peter Zijlstra
0f139300c9 perf: Ensure that IOC_OUTPUT isn't used to create multi-writer buffers
Since we want to ensure buffers only have a single
writer, we must avoid creating one with multiple.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.528215873@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:57 +02:00
Peter Zijlstra
1c024eca51 perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events
Avoid the swevent hash-table by using per-tracepoint
hlists.

Also, avoid conditionals on the fast path by ordering
with probe unregister so that we should never get on
the callback path without the data being there.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.473188012@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:56 +02:00
Peter Zijlstra
b7e2ecef92 perf, trace: Optimize tracepoints by removing IRQ-disable from perf/tracepoint interaction
Improves performance.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1274259525.5605.10352.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-21 11:37:56 +02:00
Linus Torvalds
7a9b149212 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (229 commits)
  USB: remove unused usb_buffer_alloc and usb_buffer_free macros
  usb: musb: update gfp/slab.h includes
  USB: ftdi_sio: fix legacy SIO-device header
  USB: kl5usb105: reimplement using generic framework
  USB: kl5usb105: minor clean ups
  USB: kl5usb105: fix memory leak
  USB: io_ti: use kfifo to implement write buffering
  USB: io_ti: remove unsused private counter
  USB: ti_usb: use kfifo to implement write buffering
  USB: ir-usb: fix incorrect write-buffer length
  USB: aircable: fix incorrect write-buffer length
  USB: safe_serial: straighten out read processing
  USB: safe_serial: reimplement read using generic framework
  USB: safe_serial: reimplement write using generic framework
  usb-storage: always print quirks
  USB: usb-storage: trivial debug improvements
  USB: oti6858: use port write fifo
  USB: oti6858: use kfifo to implement write buffering
  USB: cypress_m8: use kfifo to implement write buffering
  USB: cypress_m8: remove unused drain define
  ...

Fix up conflicts (due to usb_buffer_alloc/free renaming) in
	drivers/input/tablet/acecad.c
	drivers/input/tablet/kbtab.c
	drivers/input/tablet/wacom_sys.c
	drivers/media/video/gspca/gspca.c
	sound/usb/usbaudio.c
2010-05-20 21:26:12 -07:00
Linus Torvalds
f8965467f3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1674 commits)
  qlcnic: adding co maintainer
  ixgbe: add support for active DA cables
  ixgbe: dcb, do not tag tc_prio_control frames
  ixgbe: fix ixgbe_tx_is_paused logic
  ixgbe: always enable vlan strip/insert when DCB is enabled
  ixgbe: remove some redundant code in setting FCoE FIP filter
  ixgbe: fix wrong offset to fc_frame_header in ixgbe_fcoe_ddp
  ixgbe: fix header len when unsplit packet overflows to data buffer
  ipv6: Never schedule DAD timer on dead address
  ipv6: Use POSTDAD state
  ipv6: Use state_lock to protect ifa state
  ipv6: Replace inet6_ifaddr->dead with state
  cxgb4: notify upper drivers if the device is already up when they load
  cxgb4: keep interrupts available when the ports are brought down
  cxgb4: fix initial addition of MAC address
  cnic: Return SPQ credit to bnx2x after ring setup and shutdown.
  cnic: Convert cnic_local_flags to atomic ops.
  can: Fix SJA1000 command register writes on SMP systems
  bridge: fix build for CONFIG_SYSFS disabled
  ARCNET: Limit com20020 PCI ID matches for SOHARD cards
  ...

Fix up various conflicts with pcmcia tree drivers/net/
{pcmcia/3c589_cs.c, wireless/orinoco/orinoco_cs.c and
wireless/orinoco/spectrum_cs.c} and feature removal
(Documentation/feature-removal-schedule.txt).

Also fix a non-content conflict due to pm_qos_requirement getting
renamed in the PM tree (now pm_qos_request) in net/mac80211/scan.c
2010-05-20 21:04:44 -07:00
Jason Wessel
0b4b3827db x86, kgdb, init: Add early and late debug states
The kernel debugger can operate well before mm_init(), but the x86
hardware breakpoint code which uses the perf api requires that the
kernel allocators are initialized.

This means the kernel debug core needs to provide an optional arch
specific call back to allow the initialization functions to run after
the kernel has been further initialized.

The kdb shell already had a similar restriction with an early
initialization and late initialization.  The kdb_init() was moved into
the debug core's version of the late init which is called
dbg_late_init();

CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:29 -05:00
Jason Wessel
4402c153cb kdb,debug_core: Allow the debug core to receive a panic notification
It is highly desirable to trap into kdb on panic.  The debug core will
attempt to register as the first in line for the panic notifier.

CC: Ingo Molnar <mingo@elte.hu>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:28 -05:00
Jason Wessel
6d90634076 debug_core,kdb: Allow the debug core to process a recursive debug entry
This allows kdb to debug a crash with in the kms code with a
single level recursive re-entry.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:27 -05:00