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Author SHA1 Message Date
Eric Paris
637d32dc72 Capabilities: BUG when an invalid capability is requested
If an invalid (large) capability is requested the capabilities system
may panic as it is dereferencing an array of fixed (short) length.  Its
possible (and actually often happens) that the capability system
accidentally stumbled into a valid memory region but it also regularly
happens that it hits invalid memory and BUGs.  If such an operation does
get past cap_capable then the selinux system is sure to have problems as
it already does a (simple) validity check and BUG.  This is known to
happen by the broken and buggy firegl driver.

This patch cleanly checks all capable calls and BUG if a call is for an
invalid capability.  This will likely break the firegl driver for some
situations, but it is the right thing to do.  Garbage into a security
system gets you killed/bugged

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 22:01:24 +11:00
Peter Zijlstra
2002c69595 sched: release buddies on yield
Clear buddies on yield, so that the buddy rules don't schedule them
despite them being placed right-most.

This fixed a performance regression with yield-happy binary JVMs.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Lin Ming <ming.m.lin@intel.com>
2008-11-11 11:57:22 +01:00
Eric Paris
e68b75a027 When the capset syscall is used it is not possible for audit to record the
actual capbilities being added/removed.  This patch adds a new record type
which emits the target pid and the eff, inh, and perm cap sets.

example output if you audit capset syscalls would be:

type=SYSCALL msg=audit(1225743140.465:76): arch=c000003e syscall=126 success=yes exit=0 a0=17f2014 a1=17f201c a2=80000000 a3=7fff2ab7f060 items=0 ppid=2160 pid=2223 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm="setcap" exe="/usr/sbin/setcap" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1322] msg=audit(1225743140.465:76): pid=0 cap_pi=ffffffffffffffff cap_pp=ffffffffffffffff cap_pe=ffffffffffffffff

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 21:48:22 +11:00
Eric Paris
3fc689e96c Any time fcaps or a setuid app under SECURE_NOROOT is used to result in a
non-zero pE we will crate a new audit record which contains the entire set
of known information about the executable in question, fP, fI, fE, fversion
and includes the process's pE, pI, pP.  Before and after the bprm capability
are applied.  This record type will only be emitted from execve syscalls.

an example of making ping use fcaps instead of setuid:

setcap "cat_net_raw+pe" /bin/ping

type=SYSCALL msg=audit(1225742021.015:236): arch=c000003e syscall=59 success=yes exit=0 a0=1457f30 a1=14606b0 a2=1463940 a3=321b770a70 items=2 ppid=2929 pid=2963 auid=0 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1321] msg=audit(1225742021.015:236): fver=2 fp=0000000000002000 fi=0000000000000000 fe=1 old_pp=0000000000000000 old_pi=0000000000000000 old_pe=0000000000000000 new_pp=0000000000002000 new_pi=0000000000000000 new_pe=0000000000002000
type=EXECVE msg=audit(1225742021.015:236): argc=2 a0="ping" a1="127.0.0.1"
type=CWD msg=audit(1225742021.015:236):  cwd="/home/test"
type=PATH msg=audit(1225742021.015:236): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fe=1 cap_fver=2
type=PATH msg=audit(1225742021.015:236): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 21:48:18 +11:00
Eric Paris
851f7ff56d This patch will print cap_permitted and cap_inheritable data in the PATH
records of any file that has file capabilities set.  Files which do not
have fcaps set will not have different PATH records.

An example audit record if you run:
setcap "cap_net_admin+pie" /bin/bash
/bin/bash

type=SYSCALL msg=audit(1225741937.363:230): arch=c000003e syscall=59 success=yes exit=0 a0=2119230 a1=210da30 a2=20ee290 a3=8 items=2 ppid=2149 pid=2923 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=EXECVE msg=audit(1225741937.363:230): argc=2 a0="ping" a1="www.google.com"
type=CWD msg=audit(1225741937.363:230):  cwd="/root"
type=PATH msg=audit(1225741937.363:230): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fi=0000000000002000 cap_fe=1 cap_fver=2
type=PATH msg=audit(1225741937.363:230): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 21:48:14 +11:00
Bharata B Rao
ff9b48c359 sched: include group statistics in /proc/sched_debug
Impact: extend /proc/sched_debug info

Since the statistics of a group entity isn't exported directly from the
kernel, it becomes difficult to obtain some of the group statistics.
For example, the current method to obtain exec time of a group entity
is not always accurate. One has to read the exec times of all
the tasks(/proc/<pid>/sched) in the group and add them. This method
fails (or becomes difficult) if we want to collect stats of a group over
a duration where tasks get created and terminated.

This patch makes it easier to obtain group stats by directly including
them in /proc/sched_debug. Stats like group exec time would help user
programs (like LTP) to accurately measure the group fairness.

An example output of group stats from /proc/sched_debug:

cfs_rq[3]:/3/a/1
  .exec_clock                    : 89.598007
  .MIN_vruntime                  : 0.000001
  .min_vruntime                  : 256300.970506
  .max_vruntime                  : 0.000001
  .spread                        : 0.000000
  .spread0                       : -25373.372248
  .nr_running                    : 0
  .load                          : 0
  .yld_exp_empty                 : 0
  .yld_act_empty                 : 0
  .yld_both_empty                : 0
  .yld_count                     : 4474
  .sched_switch                  : 0
  .sched_count                   : 40507
  .sched_goidle                  : 12686
  .ttwu_count                    : 15114
  .ttwu_local                    : 11950
  .bkl_count                     : 67
  .nr_spread_over                : 0
  .shares                        : 0
  .se->exec_start                : 113676.727170
  .se->vruntime                  : 1592.612714
  .se->sum_exec_runtime          : 89.598007
  .se->wait_start                : 0.000000
  .se->sleep_start               : 0.000000
  .se->block_start               : 0.000000
  .se->sleep_max                 : 0.000000
  .se->block_max                 : 0.000000
  .se->exec_max                  : 1.000282
  .se->slice_max                 : 1.999750
  .se->wait_max                  : 54.981093
  .se->wait_sum                  : 217.610521
  .se->wait_count                : 50
  .se->load.weight               : 2

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Acked-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 11:44:18 +01:00
Gautham R Shenoy
5d5254f0d3 timers: handle HRTIMER_CB_IRQSAFE_UNLOCKED correctly from softirq context
Impact: fix incorrect locking triggered during hotplug-intense stress-tests

While migrating the the CB_IRQSAFE_UNLOCKED timers during a cpu-offline,
we queue them on the cb_pending list, so that they won't go
stale.

Thus, when the callbacks of the timers run from the softirq context,
they could run into potential deadlocks, since these callbacks
assume that they're running with irq's disabled, thereby annoying
lockdep!

Fix this by emulating hardirq context while running these callbacks from
the hrtimer softirq.

=================================
[ INFO: inconsistent lock state ]
2.6.27 #2
--------------------------------
inconsistent {in-hardirq-W} -> {hardirq-on-W} usage.
ksoftirqd/0/4 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (&rq->lock){++..}, at: [<c011db84>] sched_rt_period_timer+0x9e/0x1fc
{in-hardirq-W} state was registered at:
  [<c014103c>] __lock_acquire+0x549/0x121e
  [<c0107890>] native_sched_clock+0x88/0x99
  [<c013aa12>] clocksource_get_next+0x39/0x3f
  [<c0139abc>] update_wall_time+0x616/0x7df
  [<c0141d6b>] lock_acquire+0x5a/0x74
  [<c0121724>] scheduler_tick+0x3a/0x18d
  [<c047ed45>] _spin_lock+0x1c/0x45
  [<c0121724>] scheduler_tick+0x3a/0x18d
  [<c0121724>] scheduler_tick+0x3a/0x18d
  [<c012c436>] update_process_times+0x3a/0x44
  [<c013c044>] tick_periodic+0x63/0x6d
  [<c013c062>] tick_handle_periodic+0x14/0x5e
  [<c010568c>] timer_interrupt+0x44/0x4a
  [<c0150c9f>] handle_IRQ_event+0x13/0x3d
  [<c0151c14>] handle_level_irq+0x79/0xbd
  [<c0105634>] do_IRQ+0x69/0x7d
  [<c01041e4>] common_interrupt+0x28/0x30
  [<c047007b>] aac_probe_one+0x1a3/0x3f3
  [<c047ec2d>] _spin_unlock_irqrestore+0x36/0x39
  [<c01512b4>] setup_irq+0x1be/0x1f9
  [<c065d70b>] start_kernel+0x259/0x2c5
  [<ffffffff>] 0xffffffff
irq event stamp: 50102
hardirqs last  enabled at (50102): [<c047ebf4>] _spin_unlock_irq+0x20/0x23
hardirqs last disabled at (50101): [<c047edc2>] _spin_lock_irq+0xa/0x4b
softirqs last  enabled at (50088): [<c0128ba6>] do_softirq+0x37/0x4d
softirqs last disabled at (50099): [<c0128ba6>] do_softirq+0x37/0x4d

other info that might help us debug this:
no locks held by ksoftirqd/0/4.

stack backtrace:
Pid: 4, comm: ksoftirqd/0 Not tainted 2.6.27 #2
 [<c013f6cb>] print_usage_bug+0x13e/0x147
 [<c013fef5>] mark_lock+0x493/0x797
 [<c01410b1>] __lock_acquire+0x5be/0x121e
 [<c0141d6b>] lock_acquire+0x5a/0x74
 [<c011db84>] sched_rt_period_timer+0x9e/0x1fc
 [<c047ed45>] _spin_lock+0x1c/0x45
 [<c011db84>] sched_rt_period_timer+0x9e/0x1fc
 [<c011db84>] sched_rt_period_timer+0x9e/0x1fc
 [<c01210fd>] finish_task_switch+0x41/0xbd
 [<c0107890>] native_sched_clock+0x88/0x99
 [<c011dae6>] sched_rt_period_timer+0x0/0x1fc
 [<c0136dda>] run_hrtimer_pending+0x54/0xe5
 [<c011dae6>] sched_rt_period_timer+0x0/0x1fc
 [<c0128afb>] __do_softirq+0x7b/0xef
 [<c0128ba6>] do_softirq+0x37/0x4d
 [<c0128c12>] ksoftirqd+0x56/0xc5
 [<c0128bbc>] ksoftirqd+0x0/0xc5
 [<c0134649>] kthread+0x38/0x5d
 [<c0134611>] kthread+0x0/0x5d
 [<c0104477>] kernel_thread_helper+0x7/0x10
 =======================

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 10:46:42 +01:00
Frederic Weisbecker
15e6cb3673 tracing: add a tracer to catch execution time of kernel functions
Impact: add new tracing plugin which can trace full (entry+exit) function calls

This tracer uses the low level function return ftrace plugin to
measure the execution time of the kernel functions.

The first field is the caller of the function, the second is the
measured function, and the last one is the execution time in
nanoseconds.

- v3:

- HAVE_FUNCTION_RET_TRACER have been added. Each arch that support ftrace return
  should enable it.
- ftrace_return_stub becomes ftrace_stub.
- CONFIG_FUNCTION_RET_TRACER depends now on CONFIG_FUNCTION_TRACER
- Return traces printing can be used for other tracers on trace.c
- Adapt to the new tracing API (no more ctrl_update callback)
- Correct the check of "disabled" during insertion.
- Minor changes...

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 10:29:12 +01:00
Frederic Weisbecker
caf4b323b0 tracing, x86: add low level support for ftrace return tracing
Impact: add infrastructure for function-return tracing

Add low level support for ftrace return tracing.

This plug-in stores return addresses on the thread_info structure of
the current task.

The index of the current return address is initialized when the task
is the first one (init) and when a process forks (the child). It is
not needed when a task does a sys_execve because after this syscall,
it still needs to return on the kernel functions it called.

Note that the code of return_to_handler has been suggested by Steven
Rostedt as almost all of the ideas of improvements in this V3.

For purpose of security, arch/x86/kernel/process_32.c is not traced
because __switch_to() changes the current task during its execution.
That could cause inconsistency in the stored return address of this
function even if I didn't have any crash after testing with tracing on
this function enabled.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 10:29:11 +01:00
Steven Rostedt
f536aafc5a ring-buffer: replace most bug ons with warn on and disable buffer
This patch replaces most of the BUG_ONs in the ring_buffer code with
RB_WARN_ON variants. It adds some more variants as needed for the
replacement. This lets the buffer die nicely and still warn the user.

One BUG_ON remains in the code, and that is because it detects a
bad pointer passed in by the calling function, and not a bug by
the ring buffer code itself.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 09:40:34 +01:00
Steven Rostedt
5aa1ba6a6c ftrace: prevent ftrace_special from recursion
Impact: stop ftrace_special from recursion

The ftrace_special is used to help debug areas of the kernel.
Because of this, if it is put in certain locations, the fact that
it allows recursion can become a problem if the kernel developer
using does not realize that.

This patch changes ftrace_special to not allow recursion into itself
to make it more robust.

It also changes from preempt disable interrupts disable to prevent
any loss of trace entries.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 09:40:29 +01:00
Ingo Molnar
e0cb4ebcd9 Merge branch 'tracing/urgent' into tracing/ftrace
Conflicts:
	kernel/trace/trace.c
2008-11-11 09:40:18 +01:00
Ingo Molnar
45b86a96f1 Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent 2008-11-11 09:16:20 +01:00
Ingo Molnar
ae1e9130bf sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER
Impact: cleanup, change .config option name

We had this ugly config name for a long time for hysteric raisons.
Rename it to a saner name.

We still cannot get rid of it completely, until /proc/<pid>/stack
usage replaces WCHAN usage for good.

We'll be able to do that in the v2.6.29/v2.6.30 timeframe.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 08:59:20 +01:00
Oleg Nesterov
ad474caca3 fix for account_group_exec_runtime(), make sure ->signal can't be freed under rq->lock
Impact: fix hang/crash on ia64 under high load

This is ugly, but the simplest patch by far.

Unlike other similar routines, account_group_exec_runtime() could be
called "implicitly" from within scheduler after exit_notify(). This
means we can race with the parent doing release_task(), we can't just
check ->signal != NULL.

Change __exit_signal() to do spin_unlock_wait(&task_rq(tsk)->lock)
before __cleanup_signal() to make sure ->signal can't be freed under
task_rq(tsk)->lock. Note that task_rq_unlock_wait() doesn't care
about the case when tsk changes cpu/rq under us, this should be OK.

Thanks to Ingo who nacked my previous buggy patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Doug Chapman <doug.chapman@hp.com>
2008-11-11 08:01:43 +01:00
Steven Rostedt
4143c5cb36 ring-buffer: prevent infinite looping on time stamping
Impact: removal of unnecessary looping

The lockless part of the ring buffer allows for reentry into the code
from interrupts. A timestamp is taken, a test is preformed and if it
detects that an interrupt occurred that did tracing, it tries again.

The problem arises if the timestamp code itself causes a trace.
The detection will detect this and loop again. The difference between
this and an interrupt doing tracing, is that this will fail every time,
and cause an infinite loop.

Currently, we test if the loop happens 1000 times, and if so, it will
produce a warning and disable the ring buffer.

The problem with this approach is that it makes it difficult to perform
some types of tracing (tracing the timestamp code itself).

Each trace entry has a delta timestamp from the previous entry.
If a trace entry is reserved but and interrupt occurs and traces before
the previous entry is commited, the delta timestamp for that entry will
be zero. This actually makes sense in terms of tracing, because the
interrupt entry happened before the preempted entry was commited, so
one may consider the two happening at the same time. The order is
still preserved in the buffer.

With this idea, instead of trying to get a new timestamp if an interrupt
made it in between the timestamp and the test, the entry could simply
make the delta zero and continue. This will prevent interrupts or
tracers in the timer code from causing the above loop.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-10 21:47:37 -05:00
Steven Rostedt
bf5e6519b8 ftrace: disable tracing on resize
Impact: fix for bug on resize

This patch addresses the bug found here:

 http://bugzilla.kernel.org/show_bug.cgi?id=11996

When ftrace converted to the new unified trace buffer, the resizing of
the buffer was not protected as much as it was originally. If tracing
is performed while the resize occurs, then the buffer can be corrupted.

This patch disables all ftrace buffer modifications before a resize
takes place.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-10 21:47:35 -05:00
Thomas Gleixner
ae99286b4f nohz: disable tick_nohz_kick_tick() for now
Impact: nohz powersavings and wakeup regression

commit fb02fbc14d (NOHZ: restart tick
device from irq_enter()) causes a serious wakeup regression.

While the patch is correct it does not take into account that spurious
wakeups happen on x86. A fix for this issue is available, but we just
revert to the .27 behaviour and let long running softirqs screw
themself.

Disable it for now.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-11-10 22:39:27 +01:00
Thomas Gleixner
ee5f80a993 irq: call __irq_enter() before calling the tick_idle_check
Impact: avoid spurious ksoftirqd wakeups

The tick idle check which is called from irq_enter() was run before
the call to __irq_enter() which did not set the in_interrupt() bits in
preempt_count. That way the raise of a softirq woke up softirqd for
nothing as the softirq was handled on return from interrupt.

Call __irq_enter() before calling into the tick idle check code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 22:36:39 +01:00
Peter Zijlstra
5ac5c4d604 sched: clean up debug info
Impact: clean up and fix debug info printout

While looking over the sched_debug code I noticed that we printed the rq
schedstats for every cfs_rq, ammend this.

Also change nr_spead_over into an int, and fix a little buglet in
min_vruntime printing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-10 10:51:51 +01:00
Ingo Molnar
f131e2436d irq: fix typo
Impact: build fix

fix build failure on UP.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-09 22:26:45 +01:00
Thomas Gleixner
612e3684c1 genirq: fix the affinity setting in setup_irq
The affinity setting in setup irq is called before the NO_BALANCING
flag is checked and might therefore override affinity settings from the
calling code with the default setting.

Move the NO_BALANCING flag check before the call to the affinity
setting.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-09 22:23:54 +01:00
Thomas Gleixner
f6d87f4bd2 genirq: keep affinities set from userspace across free/request_irq()
Impact: preserve user-modified affinities on interrupts

Kumar Galak noticed that commit
1840475676 (genirq: Expose default irq
affinity mask (take 3))

overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.

Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-09 22:23:49 +01:00
Linus Torvalds
cb56d98e2a Merge branch 'cpus4096' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'cpus4096' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  cpumask: introduce new API, without changing anything, v3
  cpumask: new API, v2
  cpumask: introduce new API, without changing anything
2008-11-09 12:20:56 -08:00
Steven Rostedt
a309720c87 ftrace: display start of CPU buffer in trace output
Impact: change in trace output

Because the trace buffers are per cpu ring buffers, the start of
the trace can be confusing. If one CPU is very active at the
end of the trace, its history will not go as far back as the
other CPU traces.  This means that output for a particular CPU
may not appear for the first part of a trace.

To help annotate what is happening, and to prevent any more
confusion, this patch adds a line that annotates the start of
a CPU buffer output.

For example:

       automount-3495  [001]   184.596443: dnotify_parent <-vfs_write
[...]
       automount-3495  [001]   184.596449: dput <-path_put
       automount-3496  [002]   184.596450: down_read_trylock <-do_page_fault
[...]
           sshd-3497  [001]   184.597069: up_read <-do_page_fault
          <idle>-0     [000]   184.597074: __exit_idle <-exit_idle
[...]
       automount-3496  [002]   184.597257: filemap_fault <-__do_fault
          <idle>-0     [003]   184.597261: exit_idle <-smp_apic_timer_interrupt

Note, parsers of a trace output should always ignore any lines that
start with a '#'.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:54 +01:00
Steven Rostedt
769c48eb25 ftrace: force pass of preemptoff selftest
Impact: preemptoff not tested in selftest

Due to the BKL not being preemptable anymore, the selftest of the
preemptoff code can not be tested. It requires that it is called
with preemption enabled, but since the BKL is held, that is no
longer the case.

This patch simply skips those tests if it detects that the context
is not preemptable. The following will now show up in the tests:

Testing tracer preemptoff: can not test ... force PASSED
Testing tracer preemptirqsoff: can not test ... force PASSED

When the BKL is removed, or it becomes preemptable once again, then
the tests will be performed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:49 +01:00
Steven Rostedt
c76f06945b ftrace: remove trace array ctrl
Impact: remove obsolete variable in trace_array structure

With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:39 +01:00
Steven Rostedt
bbf5b1a0ce ftrace: remove ctrl_update method
Impact: Remove the ctrl_update tracer method

With the new quick start/stop method of tracing, the ctrl_update
method is out of date.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:34 +01:00
Steven Rostedt
49833fc232 ftrace: enable trace_printk by default
Impact: have the ftrace_printk enabled on startup

It is confusing to have to "echo trace_printk > /debug/tracing/iter_ctrl"
after adding ftrace_printk in the kernel.

Currently the trace_printk is set to off by default. ftrace_printk
should only be in open kernel code when used for debugging, and thus
it should be enabled by default.

It may also be used to record data within a tracer, but those ftrace_printks
should be within wrappers that are either enabled by trace_points or
have a variable protecting the code path from being entered when the
tracer is disabled.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:29 +01:00
Steven Rostedt
4519317020 ftrace: irqsoff tracer incorrect reset
Impact: fix to irqsoff tracer output

In converting to the new start / stop ftrace handling, the irqsoff
tracer start called the irqsoff reset function. irqsoff tracer is
not the same as the other traces, and it resets the buffers while
searching for the longest latency.

The reset that the irqsoff stop method calls disables the function
tracing. That means that, by starting the tracer, the function
tracer is disabled incorrectly.

This patch simply removes the call to reset which keeps the function
tracing enabled. Reset is not needed for the irqsoff stop method.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:24 +01:00
Steven Rostedt
e168e0516e ftrace: fix sched_switch API
Impact: fix for sched_switch that broke dynamic ftrace startup

The commit: tracing/fastboot: use sched switch tracer from boot tracer
broke the API of the sched_switch trace. The use of the
tracing_start/stop_cmdline record is for only recording the cmdline,
NOT recording the schedule switches themselves.

Seeing that the boot tracer broke the API to do something that it
wanted, this patch adds a new interface for the API while
puting back the original interface of the old API.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:18 +01:00
Steven Rostedt
75f5c47da3 ftrace: fix boot trace sched startup
Impact: boot tracer startup modified

The boot tracer calls into some of the schedule tracing private functions
that should not be exported. This patch cleans it up, and makes
way for further changes in the ftrace infrastructure.

This patch adds a api to assign a tracer array to the schedule
context switch tracer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:09 +01:00
Steven Rostedt
0183fb1c94 ftrace: fix set_ftrace_filter
Impact: fix of output of set_ftrace_filter

Commit ftrace: do not show freed records in available_filter_functions

Removed a bit too much from the set_ftrace_filter code, where we now see
all functions in the set_ftrace_filter file even when we set a filter.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-08 09:51:02 +01:00
Ingo Molnar
a6b0786f7f Merge branches 'tracing/ftrace', 'tracing/fastboot', 'tracing/nmisafe' and 'tracing/urgent' into tracing/core 2008-11-08 09:34:35 +01:00
Li Zefan
6d21cd6251 sched: clean up SCHED_CPUMASK_ALLOC
Impact: cleanup

The #if/#endif is ugly. Change SCHED_CPUMASK_ALLOC and
SCHED_CPUMASK_FREE to static inline functions.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-07 10:30:35 +01:00
Ingo Molnar
258594a138 Merge branch 'sched/urgent' into sched/core 2008-11-07 10:29:58 +01:00
Li Zefan
ca3273f964 sched: fix memory leak in a failure path
Impact: fix rare memory leak in the sched-domains manual reconfiguration code

In the failure path, rd is not attached to a sched domain,
so it causes a leak.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-07 08:29:58 +01:00
Li Zefan
f29c9b1ccb sched: fix a bug in sched domain degenerate
Impact: re-add incorrectly eliminated sched domain layers

(1) on i386 with SCHED_SMT and SCHED_MC enabled
	# mount -t cgroup -o cpuset xxx /mnt
	# echo 0 > /mnt/cpuset.sched_load_balance
	# mkdir /mnt/0
	# echo 0 > /mnt/0/cpuset.cpus
	# dmesg
	CPU0 attaching sched-domain:
	 domain 0: span 0 level CPU
	  groups: 0

(2) on i386 with SCHED_MC enabled but SCHED_SMT disabled
	# same with (1)
	# dmesg
	CPU0 attaching NULL sched-domain.

The bug is that some sched domains may be skipped unintentionally when
degenerating (optimizing) sched domains.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-07 08:29:57 +01:00
Niv Sardi
dcd7b4e5c0 Merge branch 'master' of git://oss.sgi.com:8090/xfs/linux-2.6 2008-11-07 15:07:12 +11:00
Linus Torvalds
e252f4db18 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: use round_jiffies_up()
  Add round_jiffies_up and related routines
  block: fix __blkdev_get() for removable devices
  generic-ipi: fix the smp_mb() placement
  blk: move blk_delete_timer call in end_that_request_last
  block: add timer on blkdev_dequeue_request() not elv_next_request()
  bio: define __BIOVEC_PHYS_MERGEABLE
  block: remove unused ll_new_mergeable()
2008-11-06 15:53:47 -08:00
Linus Torvalds
067ab19923 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: re-tune balancing
  sched: fix buddies for group scheduling
  sched: backward looking buddy
  sched: fix fair preempt check
  sched: cleanup fair task selection
2008-11-06 15:45:40 -08:00
Li Zefan
24eb089950 cgroups: fix invalid cgrp->dentry before cgroup has been completely removed
This fixes an oops when reading /proc/sched_debug.

A cgroup won't be removed completely until finishing cgroup_diput(), so we
shouldn't invalidate cgrp->dentry in cgroup_rmdir().  Otherwise, when a
group is being removed while cgroup_path() gets called, we may trigger
NULL dereference BUG.

The bug can be reproduced:

 # cat test.sh
 #!/bin/sh
 mount -t cgroup -o cpu xxx /mnt
 for (( ; ; ))
 {
	mkdir /mnt/sub
	rmdir /mnt/sub
 }
 # ./test.sh &
 # cat /proc/sched_debug

BUG: unable to handle kernel NULL pointer dereference at 00000038
IP: [<c045a47f>] cgroup_path+0x39/0x90
...
Call Trace:
 [<c0420344>] ? print_cfs_rq+0x6e/0x75d
 [<c0421160>] ? sched_debug_show+0x72d/0xc1e
...

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>		[2.6.26.x, 2.6.27.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-06 15:41:19 -08:00
Sripathi Kodi
cf7f8690e8 sched, lockdep: inline double_unlock_balance()
We have a test case which measures the variation in the amount of time
needed to perform a fixed amount of work on the preempt_rt kernel. We
started seeing deterioration in it's performance recently. The test
should never take more than 10 microseconds, but we started 5-10%
failure rate.

Using elimination method, we traced the problem to commit
1b12bbc747 (lockdep: re-annotate
scheduler runqueues).

When LOCKDEP is disabled, this patch only adds an additional function
call to double_unlock_balance(). Hence I inlined double_unlock_balance()
and the problem went away. Here is a patch to make this change.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 22:12:09 +01:00
Rusty Russell
2d3854a37e cpumask: introduce new API, without changing anything
Impact: introduce new APIs

We want to deprecate cpumasks on the stack, as we are headed for
gynormous numbers of CPUs.  Eventually, we want to head towards an
undefined 'struct cpumask' so they can never be declared on stack.

1) New cpumask functions which take pointers instead of copies.
   (cpus_* -> cpumask_*)

2) Several new helpers to reduce requirements for temporary cpumasks
   (cpumask_first_and, cpumask_next_and, cpumask_any_and)

3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
   (cpumask_var_t, alloc_cpumask_var and free_cpumask_var)

4) 'struct cpumask' for explicitness and to mark new-style code.

5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
   not NR_CPUS for time efficiency and for smaller dynamic allocations
   in future.

6) cpumask_copy() so we can allocate less than a full cpumask eventually
   (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
   definition eventually.

7) work_on_cpu() helper for doing task on a CPU, rather than saving old
   cpumask for current thread and manipulating it.

8) smp_call_function_many() which is smp_call_function_mask() except
   taking a cpumask pointer.

Note that this patch simply introduces the new functions and leaves
the obsolescent ones in place.  This is to simplify the transition
patches.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 09:05:33 +01:00
Alan Stern
9c133c469d Add round_jiffies_up and related routines
This patch (as1158b) adds round_jiffies_up() and friends.  These
routines work like the analogous round_jiffies() functions, except
that they will never round down.

The new routines will be useful for timeouts where we don't care
exactly when the timer expires, provided it doesn't expire too soon.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-06 08:42:48 +01:00
Suresh Siddha
561920a0d2 generic-ipi: fix the smp_mb() placement
smp_mb() is needed (to make the memory operations visible globally) before
sending the ipi on the sender and the receiver (on Alpha atleast) needs
smp_read_barrier_depends() in the handler before reading the call_single_queue
list in a lock-free fashion.

On x86, x2apic mode register accesses for sending IPI's don't have serializing
semantics. So the need for smp_mb() before sending the IPI becomes more
critical in x2apic mode.

Remove the unnecessary smp_mb() in csd_flag_wait(), as the presence of that
smp_mb() doesn't mean anything on the sender, when the ipi receiver is not
doing any thing special (like memory fence) after clearing the CSD_FLAG_WAIT.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-06 08:41:56 +01:00
Steven Rostedt
3e03fb7f1d ring-buffer: convert to raw spinlocks
Impact: no lockdep debugging of ring buffer

The problem with running lockdep on the ring buffer is that the
ring buffer is the core infrastructure of ftrace. What happens is
that the tracer will start tracing the lockdep code while lockdep
is testing the ring buffers locks.  This can cause lockdep to
fail due to testing cases that have not fully finished their
locking transition.

This patch converts the spin locks used by the ring buffer back
into raw spin locks which lockdep does not check.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 07:51:09 +01:00
Steven Rostedt
9036990d46 ftrace: restructure tracing start/stop infrastructure
Impact: change where tracing is started up and stopped

Currently, when a new tracer is selected via echo'ing a tracer name into
the current_tracer file, the startup is only done if tracing_enabled is
set to one. If tracing_enabled is changed to zero (by echo'ing 0 into
the tracing_enabled file) a full shutdown is performed.

The full startup and shutdown of a tracer can be expensive and the
user can lose out traces when echo'ing in 0 to the tracing_enabled file,
because the process takes too long. There can also be places that
the user would like to start and stop the tracer several times and
doing the full startup and shutdown of a tracer might be too expensive.

This patch performs the full startup and shutdown when a tracer is
selected. It also adds a way to do a quick start or stop of a tracer.
The quick version is just a flag that prevents the tracing from
taking place, but the overhead of the code is still there.

For example, the startup of a tracer may enable tracepoints, or enable
the function tracer.  The stop and start will just set a flag to
have the tracer ignore the calls when the tracepoint or function trace
is called.  The overhead of the tracer may still be present when
the tracer is stopped, but no tracing will occur. Setting the tracer
to the 'nop' tracer (or any other tracer) will perform the shutdown
of the tracer which will disable the tracepoint or disable the
function tracer.

The tracing_enabled file will simply start or stop tracing.

This change is all internal. The end result for the user should be the same
as before. If tracing_enabled is not set, no trace will happen.
If tracing_enabled is set, then the trace will happen. The tracing_enabled
variable is static between tracers. Enabling  tracing_enabled and
going to another tracer will keep tracing_enabled enabled. Same
is true with disabling tracing_enabled.

This patch will now provide a fast start/stop method to the users
for enabling or disabling tracing.

Note: There were two methods to the struct tracer that were never
 used: The methods start and stop. These were to be used as a hook
 to the reading of the trace output, but ended up not being
 necessary. These two methods are now used to enable the start
 and stop of each tracer, in case the tracer needs to do more than
 just not write into the buffer. For example, the irqsoff tracer
 must stop recording max latencies when tracing is stopped.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 07:51:03 +01:00
Steven Rostedt
0f04870148 ftrace: soft tracing stop and start
Impact: add way to quickly start stop tracing from the kernel

This patch adds a soft stop and start to the trace. This simply
disables function tracing via the ftrace_disabled flag, and
disables the trace buffers to prevent recording. The tracing
code may still be executed, but the trace will not be recorded.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 07:50:57 +01:00
Steven Rostedt
60a7ecf426 ftrace: add quick function trace stop
Impact: quick start and stop of function tracer

This patch adds a way to disable the function tracer quickly without
the need to run kstop_machine. It adds a new variable called
function_trace_stop which will stop the calls to functions from mcount
when set.  This is just an on/off switch and does not handle recursion
like preempt_disable().

It's main purpose is to help other tracers/debuggers start and stop tracing
fuctions without the need to call kstop_machine.

The config option HAVE_FUNCTION_TRACE_MCOUNT_TEST is added for archs
that implement the testing of the function_trace_stop in the mcount
arch dependent code. Otherwise, the test is done in the C code.

x86 is the only arch at the moment that supports this.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-06 07:50:51 +01:00