The function graph tracer replaces the return address with a hook
to trace the exit of the function call. This hook will finish by
returning to the real location the function should return to.

But the current implementation uses a ret to jump to the real
return location. This causes a imbalance between calls and ret.
That is the original function does a call, the ret goes to the
handler and then the handler does a ret without a matching call.

Although the function graph tracer itself still breaks the branch
predictor by replacing the original ret, by using a second ret and
causing an imbalance, it breaks the predictor even more.

This patch replaces the ret with a jmp to keep the calls and ret
balanced. I tested this on one box and it showed a 1.7% increase in
performance. Another box only showed a small 0.3% increase. But no
box that I tested this on showed a decrease in performance by
making this change.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091013203425.042034383@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core

Remove the ftrace_trace_addr() function as only its off-case is
implemented and there are no users of it currently.

But we keep ftrace_graph_addr() off-case, in case someone come to use
the function graph tracer to profit from top-level callers filtering.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

Do this rename because set_ftrace is too much generic and not enough
self-explainable as a name.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

Merge reason: Pick up tracing/filters fix from the urgent queue,
              we will queue up dependent patches.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Every time we set a filter, we leak memory allocated by
postfix_append_operand() and postfix_append_op().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: <stable@kernel.org> # for v2.6.31.x
LKML-Reference: <4AD3D7D9.4070400@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Add a command line parameter to allow limiting the function graphs
that are traced on boot up from the given top-level callers , when
ftrace=function_graph is specified.

This patch adds the following command line option:
ftrace_graph_filter=function-list

Where function-list is a comma separated list of functions to filter.

[fweisbec@gmail.com: picked the documentation changes from the v2 patch]
Signed-off-by: Stefan Assmann <sassmann@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AD2DEB9.2@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

- Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt.
- Strip MODULE_NAME from pr_<level>s.
- Remove MODULE_NAME definition.
Signed-off-by: Joe Perches <joe@perches.com>
LKML-Reference: <3bb66cc7f85f77b9416902e1be7076f7e3f4ad48.1254701151.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

- Remove prefixes from pr_<level>, use pr_fmt(fmt).

No change in output.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <9b377eefae9e28c599dd4a17bdc81172965e9931.1254701151.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The addition of trace_array_{v}printk used the wrong function for
trace_vprintk to call. This broke trace_marker and trace_vprintk
itself. Although trace_printk may not have been affected by those
that end up calling trace_vbprintk.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Just using the tr->buffer for the API to trace_buffer_lock_reserve
is not good enough. This is because the tr->buffer may change, and we
do not want to commit with a different buffer that we reserved from.

This patch uses a local variable to hold the buffer that was used to
reserve and commit with.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

fix warnings that caused the API change of trace_buffer_lock_reserve()
change files: kernel/trace/trace_hw_branch.c
              kernel/trace/trace_branch.c
Signed-off-by: Zhenwen Xu <helight.xu@gmail.com>
LKML-Reference: <20091008012146.GA4170@helight>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Due to legacy code from back when the dynamic tracer used a daemon,
only core kernel code was checking for failures. This is no longer
the case. We must check for failures any time we perform text modifications.

Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

When the module is about the unload we release its call records.
The ftrace_release function was given wrong values representing
the module core boundaries, thus not releasing its call records.

Plus making ftrace_release function module specific.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1254934835-363-3-git-send-email-jolsa@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

The lock_depth and preempt_count numbers in the latency format is
transposed.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

The state char variable S should be reassigned, if S == 0.

We are missing the state of the task that is going to sleep for the
context switch events (in the raw mode).

Fortunately the problem arises with the sched_switch/wake_up
tracers, not the sched trace events.

The formers are legacy now. But still, that was buggy.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4AC43118.6050409@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In the event->profile_enable() failure path, we release the per cpu
buffers using kfree which is wrong because they are per cpu pointers.
Although free_percpu only wraps kfree for now, that may change in the
future so lets use the correct way.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

When we call the profile_enable() callback of an event, we release the
shared perf event tracing buffers unconditionnaly in the failure path.
This is wrong because there may be other users of these. Then check the
total refcount before doing this.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

* 'for-linus' of git://www.linux-m32r.org/git/takata/linux-2.6_dev:
  m32r: Fix IPI function calls for SMP
  m32r: Fix set_memory() for DISCONTIGMEM
  m32r: add rtc_lock variable
  m32r: define ioread* and iowrite* macros
  m32r: export delay loop symbols
  m32r: fix tme_handler

A couple of people have hit the WARN_ON() in drivers/char/tty_io.c,
tty_open() that is unhappy about seeing the tty line discipline go away
during the tty hangup. See for example

	http://bugzilla.kernel.org/show_bug.cgi?id=14255

and the reason is that we do the tty_ldisc_halt() outside the
ldisc_mutex in order to be able to flush the scheduled work without a
deadlock with vhangup_work.

However, it turns out that we can solve this particular case by

 - using "cancel_delayed_work_sync()" in tty_ldisc_halt(), which waits
   for just the particular work, rather than synchronizing with any
   random outstanding pending work.

   This won't deadlock, since the buf.work we synchronize with doesn't
   care about the ldisc_mutex, it just flushes the tty ldisc buffers.

 - realize that for this particular case, we don't need to wait for any
   hangup work, because we are inside the hangup codepaths ourselves.

so as a result we can just drop the flush_scheduled_work() entirely, and
then move the tty_ldisc_halt() call to inside the mutex.  That way we
never expose the partially torn down ldisc state to tty_open(), and hold
the ldisc_mutex over the whole sequence.
Reported-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Heinz Diehl <htd@fancy-poultry.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fixes the m32r SMP kernel after 2.6.27.

A part of the following patch breaks m32r SMP operation.
> m32r: convert to generic helpers for IPI function calls
> commit 7b7426c8

In the above patch, a CALL_FUNC_SINGLE_IPI was newly introduced,
but the its IPI vector number was wrong in the patch code.

The m32r SMP kernel hanged-up during boot operation, because
the CPU_BOOT_IPI was called instead of CALL_FUNC_SINGLE_IPI
(CPU_BOOT_IPI had no side effect at that time because the 2nd
core had already been started up),
as a result, csd_unlock() was not called, then a dead lock
occurred in csd_lock_wait() after the detection of Compact Flash
memory as IDE generic disk.
Signed-off-by: Toshihiro HANAWA <hanawa@ccs.tsukuba.ac.jp>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

In case CONFIG_DISCONTIGMEM is set, the memory size of system was
always determined by CONFIG_MEMORY_SIZE and was not changeable.

This patch fixes set_memory() of arch/m32r/mm/discontig.c so that
we can specify memory size by the "mem=<size>" kernel parameter.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

Add a spinlock variable "rtc_lock".
This is taken from arch/arm/kernel/time.c.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

Define ioread* and iowrite* macros to fix the following build errors:

  CC [M]  drivers/uio/uio_smx.o
drivers/uio/uio_smx.c: In function 'smx_handler':
drivers/uio/uio_smx.c:31: error: implicit declaration of function 'ioread32'
drivers/uio/uio_smx.c:37: error: implicit declaration of function 'iowrite32'
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

- Move EXPORT_SYMBOL lines of delay loop functions
  from arch/m32r/kernel/m32r_ksyms.c to arch/m32r/lib/delay.c.
- Export __ndelay.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

Fix pmd_bad check code of tme_handler (TLB Miss Exception handler).
The correct _KERNPG_TABLE value is not 0x263(=611) but 0x163.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>

* 'for-linus' of ssh://master.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (21 commits)
  ALSA: usb - Use strlcat() correctly
  ALSA: Fix invalid __exit in sound/mips/*.c
  ALSA: hda - Fix / improve ALC66x parser
  ALSA: ctxfi: Swapped SURROUND-SIDE mute
  sound: Make keywest_driver static
  ALSA: intel8x0 - Mute External Amplifier by default for Sony VAIO VGN-B1VP
  ALSA: hda - Fix digita/analog mic auto-switching with IDT codecs
  ASoC: fix kconfig order of Blackfin drivers
  ALSA: hda - Added quirk to enable sound on Toshiba NB200
  ASoC: Fix dependency of CONFIG_SND_PXA2XX_SOC_IMOTE2
  ALSA: Don't assume i2c device probing always succeeds
  ALSA: intel8x0 - Mute External Amplifier by default for Sony VAIO VGN-T350P
  ALSA: echoaudio - Re-enable the line-out control for the Mia card
  ALSA: hda - Resurrect input-source mixer of ALC268 model=acer
  ALSA: hda - Analog Devices AD1984A add HP Touchsmart model
  ALSA: hda - Add HP Pavilion dv4t-1300 to MSI whitelist
  ALSA: hda - CD-audio sound for hda-intel conexant benq laptop
  ASoC: DaVinci: Correct McASP FIFO initialization
  ASoC: Davinci: Fix race with cpu_dai->dma_data
  ASoC: DaVinci: Fix divide by zero error during 1st execution
  ...

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  [PATCH] ext4: retry failed direct IO allocations
  ext4: Fix build warning in ext4_dirty_inode()
  ext4: drop ext4dev compat
  ext4: fix a BUG_ON crash by checking that page has buffers attached to it

On a 256M filesystem, doing this in a loop:

        xfs_io -F -f -d -c 'pwrite 0 64m' test
        rm -f test

eventually leads to ENOSPC.  (the xfs_io command does a
64m direct IO write to the file "test")

As with other block allocation callers, it looks like we need to
potentially retry the allocations on the initial ENOSPC.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This fixes the following warning:

fs/ext4/inode.c: In function 'ext4_dirty_inode':
fs/ext4/inode.c:5615: warning: unused variable 'current_handle'

We remove the jbd_debug() statement which does use current_handle, as
it's not terribly important in the grand scheme of things.

Thanks to Stephen Rothwell for pointing this out.
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

* master.kernel.org:/home/rmk/linux-2.6-arm: (25 commits)
  ARM: 5728/1: Proper prefetch abort handling on ARMv6 and ARMv7
  ARM: 5727/1: Pass IFSR register to do_PrefetchAbort()
  ARM: 5740/1: fix valid_phys_addr_range() range check
  ARM: 5739/1: ARM: allow empty ATAG_CORE
  ARM: 5735/1: sa1111: CodingStyle cleanups
  ARM: 5738/1: Correct TCM documentation
  ARM: 5734/1: arm: fix compilation of entry-common.S for older CPUs
  ARM: 5733/1: fix bcmring compile error
  ARM: 5732/1: remove redundant include file
  ARM: 5731/2: Fix U300 generic GPIO, remove ifdefs from MMCI v3
  ARM: Ensure do_cache_op takes mmap_sem
  ARM: Fix __cpuexit section mismatch warnings
  ARM: Don't allow highmem on SMP platforms without h/w TLB ops broadcast
  ARM: includecheck fix: mach-davinci, board-dm365-evm.c
  ARM: Remove unused CONFIG SA1100_H3XXX
  ARM: Fix warning: unused variable 'highmem'
  ARM: Fix warning: #warning syscall migrate_pages not implemented
  ARM: Fix SA11x0 clocksource warning
  ARM: Fix SA1100 Neponset serial section mismatch
  ARM: Fix SA1100 Assabet/Neponset PCMCIA section mismatch warnings
  ...

Currently, on ARMv6 and ARMv7, if an application tries to execute
code (or garbage) on non-executable page it hangs. It caused by
incorrect prefetch abort handling. Now every prefetch abort
processes as a translation fault.

To fix this we have to analyze instruction fault status register
to figure out reason why we've got the abort and process it
accordingly.

To make IFSR different from DFSR we set bit 31 which is reserved in
both IFSR and DFSR.

This patch also tries to protect from future hangs on unexpected
exceptions. An application will be killed if unexpected exception
type was received.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Instruction fault status register, IFSR, was introduced on ARMv6 to
provide status information about the last insturction fault. It
needed for proper prefetch abort handling.

Now we have three prefetch abort model:

  * legacy - for CPUs before ARMv6. They doesn't provide neither
    IFSR nor IFAR. We simulate IFSR with section translation fault
    status for them to generalize code;
  * ARMv6 - provides IFSR, but not IFAR;
  * ARMv7 - provides both IFSR and IFAR.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Commit 1522ac3e
("Fix virtual to physical translation macro corner cases")
breaks the end of memory check in valid_phys_addr_range().
The modified expression results in the apparent /dev/mem size
being 2 bytes smaller than what it actually is.

This patch reworks the expression to correctly check the address,
while maintaining use of a valid address to __pa().
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

From: David Brown <davidb@quicinc.com>

The ATAG_CORE is allowed to be empty.  Although this is handled
by parse_tag_core(), __vet_atags during startup rejects this tag
unless it contains data.  Allow the initial tag to be either the
full size, or empty.
Signed-off-by: David Brown <davidb@quicinc.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

EXPORT_* macros should follow immediately after the closing function
brace line.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Conflicts:
	MAINTAINERS

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (46 commits)
  cnic: Fix NETDEV_UP event processing.
  uvesafb/connector: Disallow unpliviged users to send netlink packets
  pohmelfs/connector: Disallow unpliviged users to configure pohmelfs
  dst/connector: Disallow unpliviged users to configure dst
  dm/connector: Only process connector packages from privileged processes
  connector: Removed the destruct_data callback since it is always kfree_skb()
  connector/dm: Fixed a compilation warning
  connector: Provide the sender's credentials to the callback
  connector: Keep the skb in cn_callback_data
  e1000e/igb/ixgbe: Don't report an error if devices don't support AER
  net: Fix wrong sizeof
  net: splice() from tcp to pipe should take into account O_NONBLOCK
  net: Use sk_mark for routing lookup in more places
  sky2: irqname based on pci address
  skge: use unique IRQ name
  IPv4 TCP fails to send window scale option when window scale is zero
  net/ipv4/tcp.c: fix min() type mismatch warning
  Kconfig: STRIP: Remove stale bits of STRIP help text
  NET: mkiss: Fix typo
  tg3: Remove prev_vlan_tag from struct tx_ring_info
  ...