Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

Guennadi Liakhovetski noticed that the end condition for the loop in
bitmap_find_free_region() is wrong, and the "return if error" was also
using the wrong conditional that would only trigger if the bitmap was an
exact multiple of the allocation size, which is not necessarily the case
with dma_alloc_from_coherent().

Such a failure would end up in bitmap_find_free_region() accessing
beyond the end of the bitmap.
Reported-by: Guennadi Liakhovetski <lg@denx.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In a private email conversation I explained how the ring buffer
page worked by using silly ASCII art. Ingo suggested that I add
that to the comments of the code.

Here it is.
Requested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Unlike TRACE_FORMAT() macros, the TRACE_EVENT() macros do not show
the event name in the trace file. Knowing the event type in the trace
output is very useful.

Instead of:

   task swapper:0 [140] ==> ntpd:3308 [120]

We now have:

   sched_switch: task swapper:0 [140] ==> ntpd:3308 [120]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

commit c3ffc7a4
"Don't use tracing_record_cmdline() in workqueue tracer"
has a race window.

find_task_by_vpid() requires task_list_lock().

LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Introduce softirq entry/exit tracepoints. These are useful for
augmenting existing tracers, and to figure out softirq frequencies and
timings.

[
  s/irq_softirq_/softirq_/ for trace point names and
  Fixed printf format in TRACE_FORMAT macro
   - Steven Rostedt
]

LKML-Reference: <20090312183603.GC3352@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Create a 'softirq_to_name' array, which is indexed by softirq #, so
that we can easily convert between the softirq index # and its name, in
order to get more meaningful output messages.

LKML-Reference: <20090312183336.GB3352@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

If the stack tracing is disabled (by default) the stack_trace file
will only contain the header:

 # cat /debug/tracing/stack_trace
        Depth    Size      Location    (0 entries)
        -----    ----      --------

This can be frustrating to a developer that does not realize that the
stack tracer is disabled. This patch adds the following text:

  # cat /debug/tracing/stack_trace
        Depth    Size      Location    (0 entries)
        -----    ----      --------
 #
 #  Stack tracer disabled
 #
 # To enable the stack tracer, either add 'stacktrace' to the
 # kernel command line
 # or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'
 #
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

The stack tracer use to look like this:

 # cat /debug/tracing/stack_trace
         Depth  Size      Location    (57 entries)
         -----  ----      --------
  0)     5088      16   mempool_alloc_slab+0x16/0x18
  1)     5072     144   mempool_alloc+0x4d/0xfe
  2)     4928      16   scsi_sg_alloc+0x48/0x4a [scsi_mod]

Now it looks like this:

 # cat /debug/tracing/stack_trace

        Depth    Size      Location    (57 entries)
        -----    ----      --------
  0)     5088      16   mempool_alloc_slab+0x16/0x18
  1)     5072     144   mempool_alloc+0x4d/0xfe
  2)     4928      16   scsi_sg_alloc+0x48/0x4a [scsi_mod]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

The binary printk saves a pointer to the format string in the ring buffer.
On output, the format is processed. But if the user is reading the
ring buffer through a binary interface, the pointer is meaningless.

This patch creates a file called printk_formats that maps the pointers
to the formats.

 # cat /debug/tracing/printk_formats
0xffffffff80713d40 : "irq_handler_entry: irq=%d handler=%s\n"
0xffffffff80713d48 : "lock_acquire: %s%s%s\n"
0xffffffff80713d50 : "lock_release: %s\n"
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: speed up on event tracing

The event_trace_printk is currently a wrapper function that calls
trace_vprintk. Because it uses a variable for the fmt it misses out
on the optimization of using the binary printk.

This patch makes event_trace_printk into a macro wrapper to use the
fmt as the same as the trace_printks.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

The bprint record is using TRACE_PRINT when it should be TRACE_BPRINT.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: fix callsites with dynamic format strings

Since its new binary implementation, trace_printk() internally uses static
containers for the format strings on each callsites. But the value is
assigned once at build time, which means that it can't take dynamic
formats.

So this patch unearthes the raw trace_printk implementation for the callers
that will need trace_printk to be able to carry these dynamic format
strings. The trace_printk() macro will use the appropriate implementation
for each callsite. Most of the time however, the binary implementation will
still be used.

The other impact of this patch is that mmiotrace_printk() will use the old
implementation because it calls the low level trace_vprintk and we can't
guess here whether the format passed in it is dynamic or not.

Some parts of this patch have been written by Steven Rostedt (most notably
the part that chooses the appropriate implementation for each callsites).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: do not confuse user on small trace buffer sizes

When the system boots up, the trace buffer is small to conserve memory.
It is only two pages per online CPU. When the tracer is used, it expands
to the default value.

This can confuse the user if they look at the buffer size and see only
7, but then later they see 1408.

 # cat /debug/tracing/buffer_size_kb
7

 # echo sched_switch > /debug/tracing/current_tracer

 # cat /debug/tracing/buffer_size_kb
1408

This patch tries to help remove this confustion by showing that the
buffer has not been expanded.

 # cat /debug/tracing/buffer_size_kb
7 (expanded: 1408)
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: speed up and remove possible races

The get_online_cpus was added to the ring buffer because the original
design would free the ring buffer on a CPU that was being taken
off line. The final design kept the ring buffer around even when the
CPU was taken off line. This is to allow a user to still read the
information on that ring buffer.

Most of the get_online_cpus are no longer needed since the ring buffer will
not disappear from the use cases.
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

The hotplug code in the ring buffers is for use with CPU hotplug,
not generic hotplug.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: prevent races with ring_buffer_expanded

This patch places the expanding of the tracing buffer under the
protection of the trace_types_lock mutex. It is highly unlikely
that there would be any contention, but better safe than sorry.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Impact: cleanup

Some of the comments about the trace buffer resizing is gobbledygook.
And I wonder why people question if I'm a native English speaker.

This patch makes the comments make a bit more sense.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

Merge branch 'tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/ftrace-merge

Impact: cleanup

The naming clashes with upcoming softirq tracepoints, so rename the
APIs to lockdep_*().
Requested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: remove unused -r option for module-init-tool depmod
  kbuild: fix 'make rpm' when CONFIG_LOCALVERSION_AUTO=y and using SCM tree
  kbuild: fix mkspec to cleanup RPM_BUILD_ROOT
  kbuild: fix C libary confusion in unifdef.c due to getline()

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  cpumask: mm_cpumask for accessing the struct mm_struct's cpu_vm_mask.
  cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed.

* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: Valid filesystems are flagged as bad by the corrupted fs patch

* 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  hwmon: (f75375s) Remove unnecessary and confusing initialization
  hwmon: (it87) Properly decode -128 degrees C temperature
  hwmon: (lm90) Document support for the MAX6648/6692 chips
  hwmon: (abituguru3) Fix I/O error handling

Trivial patch to fix bad links in the ext2 and ext3 documentation.
Signed-off-by: Jody McIntyre <scjody@sun.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'fixes-20090312' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/pci:
  PCIe: portdrv: call pci_disable_device during remove
  pci: Fix typo in message while disabling HT MSI mapping
  pci: don't disable too many HT MSI mapping
  powerpc/pseries: The RPA PCI hotplug driver depends on EEH
  PCIe: AER: during disable, check subordinate before walking
  PCI: Add PCI quirk to disable L0s ASPM state for 82575 and 82598

STag zero is a special STag that allows consumers to access any bus
address without registering memory.  The nes driver unfortunately
allows STag zero to be used even with QPs created by unprivileged
userspace consumers, which means that any process with direct verbs
access to the nes device can read and write any memory accessible to
the underlying PCI device (usually any memory in the system).  Such
access is usually given for cluster software such as MPI to use, so
this is a local privilege escalation bug on most systems running this
driver.

The driver was using STag zero to receive the last streaming mode
data; to allow STag zero to be disabled for unprivileged QPs, the
driver now registers a special MR for this data.

Cc: <stable@kernel.org>
Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There was a report of a data corruption
http://lkml.org/lkml/2008/11/14/121.  There is a script included to
reproduce the problem.

During testing, I encountered a number of strange things with ext3, so I
tried ext2 to attempt to reduce complexity of the problem.  I found that
fsstress would quickly hang in wait_on_inode, waiting for I_LOCK to be
cleared, even though instrumentation showed that unlock_new_inode had
already been called for that inode.  This points to memory scribble, or
synchronisation problme.

i_state of I_NEW inodes is not protected by inode_lock because other
processes are not supposed to touch them until I_LOCK (and I_NEW) is
cleared.  Adding WARN_ON(inode->i_state & I_NEW) to sites where we modify
i_state revealed that generic_sync_sb_inodes is picking up new inodes from
the inode lists and passing them to __writeback_single_inode without
waiting for I_NEW.  Subsequently modifying i_state causes corruption.  In
my case it would look like this:

CPU0                            CPU1
unlock_new_inode()              __sync_single_inode()
 reg <- inode->i_state
 reg -> reg & ~(I_LOCK|I_NEW)   reg <- inode->i_state
 reg -> inode->i_state          reg -> reg | I_SYNC
                                reg -> inode->i_state

Non-atomic RMW on CPU1 overwrites CPU0 store and sets I_LOCK|I_NEW again.

Fix for this is rather than wait for I_NEW inodes, just skip over them:
inodes concurrently being created are not subject to data integrity
operations, and should not significantly contribute to dirty memory
either.

After this change, I'm unable to reproduce any of the added warnings or
hangs after ~1hour of running.  Previously, the new warnings would start
immediately and hang would happen in under 5 minutes.

I'm also testing on ext3 now, and so far no problems there either.  I
don't know whether this fixes the problem reported above, but it fixes a
real problem for me.

Cc: "Jorge Boncompte [DTI2]" <jorge@dti2.net>
Reported-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Even when page reclaim is under mem_cgroup, # of scan page is determined by
status of global LRU. Fix that.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

No software visible difference from revision A.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Samuel Ortiz <sameo@openedhand.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently we disable the Acer WMI backlight device if there is no ACPI
backlight device.  As a result, we end up with no backlight device at all.
 We should instead disable it if there is an ACPI device, as the other
laptop drivers do.  This regression was introduced in febf2d95 ("Acer-WMI:
fingers off backlight if video.ko is serving this functionality").

Each laptop driver with backlight support got a similar change around
febf2d95.  The changes to the other drivers look correct; see e.g.
a598c82f for a similar but correct change.  The regression is also in
2.6.28.
Signed-off-by: Michael Spang <mspang@csclub.uwaterloo.ca>
Acked-by: Thomas Renninger <trenn@suse.de>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Len Brown <len.brown@intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The s3cmci driver is calling s3c2410_dma_config with incorrect data for
the DCON register.  The S3C2410_DCON_HWTRIG is implicit in the channel
configuration and the device selection of S3C2410_DCON_CH0_SDI is
incorrect as the DMA system may not select channel 0.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Unfortunately, Linux Foundation funding for my work on
man-pages/testing/doc under the auspices of the LF documentation
fellowship unfortunately ran out a short while ago (after earlier attempts
to seek funding, only Google stepped forward with a bit of further funding
for the position), so the patch below acknowledges something closer to
reality.

Unfortunately, there will (probably very) soon be a further downgrade from
"Maintained" to "Odd Fixes" or "Orphan", unless some funding miracle
occurs.  So, if anyone is looking to become man-pages maintainer, there
may soon be an opening (okay, don't trample me in the rush ;-).)
Signed-off-by: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The 'battery remaining capacity' calculation in
drivers/power/ds2760_battery.c lacks a parameter check to a division
operation which causes the kernel to oops on my board.

[   21.233750] Division by zero in kernel.
[   21.237646] [<c002955c>] (__div0+0x0/0x20) from [<c012561c>] (Ldiv0+0x8/0x10)
[   21.244816] [<c01bef34>] (ds2760_battery_read_status+0x0/0x2a4) from [<c01bf3a4>] (ds2760_battery_get_property+0x30/0xdc)
[   21.255803]  r8:c03a22c0 r7:c7886100 r6:00000009 r5:c782fe7c r4:c7886084
[   21.262518] [<c01bf374>] (ds2760_battery_get_property+0x0/0xdc) from [<c01bde98>] (power_supply_show_property+0x48/0x114)
[   21.273480]  r6:c7996000 r5:00000009 r4:00000000
[   21.278111] [<c01bde50>] (power_supply_show_property+0x0/0x114) from [<c01be158>] (power_supply_uevent+0x188/0x280)
[   21.288537]  r8:00000001 r7:c7886100 r6:c7996000 r5:000000b4 r4:00000000
[   21.295222] [<c01bdfd0>] (power_supply_uevent+0x0/0x280) from [<c015c664>] (dev_uevent+0xd4/0x10c)
[   21.304199] [<c015c590>] (dev_uevent+0x0/0x10c) from [<c0128440>] (kobject_uevent_env+0x180/0x390)
[   21.313170]  r5:00000000 r4:c78860ac
[   21.316725] [<c01282c0>] (kobject_uevent_env+0x0/0x390) from [<c0128664>] (kobject_uevent+0x14/0x18)
[   21.325850] [<c0128650>] (kobject_uevent+0x0/0x18) from [<c01bdc34>] (power_supply_changed_work+0x5c/0x70)
[   21.335506] [<c01bdbd8>] (power_supply_changed_work+0x0/0x70) from [<c004d290>] (run_workqueue+0xbc/0x144)
[   21.345167]  r4:c7812040
[   21.347716] [<c004d1d4>] (run_workqueue+0x0/0x144) from [<c004d94c>] (worker_thread+0xa8/0xbc)
[   21.356296]  r7:c7812040 r6:c7820b00 r5:c782ffa4 r4:c7812048
[   21.361957] [<c004d8a4>] (worker_thread+0x0/0xbc) from [<c0051008>] (kthread+0x5c/0x94)
[   21.369971]  r7:00000000 r6:c004d8a4 r5:c7812040 r4:c782e000
[   21.375612] [<c0050fac>] (kthread+0x0/0x94) from [<c00403d0>] (do_exit+0x0/0x688)
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Acked-by: Matt Reimer <mreimer@vpop.net>
Acked-by: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In sget(), destroy_super(s) is called with s->s_umount held, which makes
lockdep unhappy.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>