There's times during debugging that it is helpful to see traces of early
boot functions. But the tracers are initialized at device_initcall()
which is quite late during the boot process. Setting the kernel command
line parameter ftrace=function will not show anything until the function
tracer is initialized. This prevents being able to trace functions before
device_initcall().

There's no reason that the tracers need to be initialized so late in the
boot process. Move them up to core_initcall() as they still need to come
after early_initcall() which initializes the tracing buffers.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

 * remove old string conversions with kstrto*

Link: http://lkml.kernel.org/r/20120926200838.GC1244@0x90.atSigned-off-by: NDaniel Walter <sahne@0x90.at>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add a new filter update interface ftrace_set_filter_ip()
to set ftrace filter by ip address, not only glob pattern.

Link: http://lkml.kernel.org/r/20120605102808.27845.67952.stgit@localhost.localdomain

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add selftests to test the function tracing recursion protection actually
does work. It also tests if a ftrace_ops states it will perform its own
protection. Although, even if the ftrace_ops states it will protect itself,
the ftrace infrastructure may still provide protection if the arch does
not support all features or another ftrace_ops is registered.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As more users of the function tracer utility are being added, they do
not always add the necessary recursion protection. To protect from
function recursion due to tracing, if the callback ftrace_ops does not
specifically specify that it protects against recursion (by setting
the FTRACE_OPS_FL_RECURSION_SAFE flag), the list operation will be
called by the mcount trampoline which adds recursion protection.

If the flag is set, then the function will be called directly with no
extra protection.

Note, the list operation is called if more than one function callback
is registered, or if the arch does not support all of the function
tracer features.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add a way to have different functions calling different trampolines.
If a ftrace_ops wants regs saved on the return, then have only the
functions with ops registered to save regs. Functions registered by
other ops would not be affected, unless the functions overlap.

If one ftrace_ops registered functions A, B and C and another ops
registered fucntions to save regs on A, and D, then only functions
A and D would be saving regs. Function B and C would work as normal.
Although A is registered by both ops: normal and saves regs; this is fine
as saving the regs is needed to satisfy one of the ops that calls it
but the regs are ignored by the other ops function.

x86_64 implements the full regs saving, and i386 just passes a NULL
for regs to satisfy the ftrace_ops passing. Where an arch must supply
both regs and ftrace_ops parameters, even if regs is just NULL.

It is OK for an arch to pass NULL regs. All function trace users that
require regs passing must add the flag FTRACE_OPS_FL_SAVE_REGS when
registering the ftrace_ops. If the arch does not support saving regs
then the ftrace_ops will fail to register. The flag
FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED may be set that will prevent the
ftrace_ops from failing to register. In this case, the handler may
either check if regs is not NULL or check if ARCH_SUPPORTS_FTRACE_SAVE_REGS.
If the arch supports passing regs it will set this macro and pass regs
for ops that request them. All other archs will just pass NULL.

Link: Link: http://lkml.kernel.org/r/20120711195745.107705970@goodmis.org

Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Return as the 4th paramater to the function tracer callback the pt_regs.

Later patches that implement regs passing for the architectures will require
having the ftrace_ops set the SAVE_REGS flag, which will tell the arch
to take the time to pass a full set of pt_regs to the ftrace_ops callback
function. If the arch does not support it then it should pass NULL.

If an arch can pass full regs, then it should define:
 ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1

Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.orgReviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As the function tracer starts to get more features, the support for
theses features will spread out throughout the different architectures
over time. These features boil down to what each arch does in the
mcount trampoline (the ftrace_caller).

Currently there's two features that are not the same throughout the
archs.

 1) Support to stop function tracing before the callback
 2) passing of the ftrace ops

Both of these require placing an indirect function to support the
features if the mcount trampoline does not.

On a side note, for all architectures, when more than one callback
is registered to the function tracer, an intermediate 'list' function
is called by the mcount trampoline to iterate through the callbacks
that are registered.

Instead of making a separate function for each of these features,
and requiring several indirect calls, just use the single 'list' function
as the intermediate, to handle all cases. If an arch does not support
the 'stop function tracing' or the passing of ftrace ops, just force
it to use the list function that will handle the features required.

This makes the code cleaner and simpler and removes a lot of
 #ifdefs in the code.

Link: http://lkml.kernel.org/r/20120612225424.495625483@goodmis.orgReviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently the function trace callback receives only the ip and parent_ip
of the function that it traced. It would be more powerful to also return
the ops that registered the function as well. This allows the same function
to act differently depending on what ftrace_ops registered it.

Link: http://lkml.kernel.org/r/20120612225424.267254552@goodmis.orgReviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

register_ftrace_function() checks ftrace_disabled and calls
__register_ftrace_function which does it again.

Drop the first check and add the unlikely hint to the second one. Also,
drop the label as John correctly notices.

No functional change.

Link: http://lkml.kernel.org/r/20120329171140.GE6409@aftab

Cc: Borislav Petkov <bp@amd64.org>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

To remove duplicate code, have the ftrace arch_ftrace_update_code()
use the generic ftrace_modify_all_code(). This requires that the
default ftrace_replace_code() becomes a weak function so that an
arch may override it.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Rename __ftrace_modify_code() to ftrace_modify_all_code() and make
it global for all archs to use. This will remove the duplication
of code, as archs that can modify code without stop_machine()
can use it directly outside of the stop_machine() call.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

ftrace_location() is passed an addr, and returns 1 if the addr is
on a ftrace nop (or caller to ftrace_caller), and 0 otherwise.

To let kprobes know if it should move a breakpoint or not, it
must return the actual addr that is the start of the ftrace nop.
This way a kprobe placed on the location of a ftrace nop, can
instead be placed on the instruction after the nop. Even if the
probe addr is on the second or later byte of the nop, it can
simply be moved forward.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Both ftrace_location() and ftrace_text_reserved() do basically the same thing.
They search to see if an address is in the ftace table (contains an address
that may change from nop to call ftrace_caller). The difference is
that ftrace_location() searches a single address, but ftrace_text_reserved()
searches a range.

This also makes the ftrace_text_reserved() faster as it now uses a bsearch()
instead of linearly searching all the addresses within a page.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As all records in a page of the ftrace table are sorted, we can
speed up the search algorithm by checking if the address to look for
falls in between the first and last record ip on the page.

This speeds up both the ftrace_location() and ftrace_text_reserved()
algorithms, as it can skip full pages when the search address is
not in them.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The ftrace_record_ip() and ftrace_alloc_dyn_node() were from the
time of the ftrace daemon. Although they were still used, they
still make things a bit more complex than necessary.

Move the code into the one function that uses it, and remove the
helper functions.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Instead of just sorting the ip's of the functions per ftrace page,
sort the entire list before adding them to the ftrace pages.

This will allow the bsearch algorithm to be sped up as it can
also sort by pages, not just records within a page.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

It's appropriate to use __seq_open_private interface to open
some of trace seq files, because it covers all steps we are
duplicating in tracing code - zallocating the iterator and
setting it as seq_file's private.

Using this for following files:
  trace
  available_filter_functions
  enabled_functions

Link: http://lkml.kernel.org/r/1335342219-2782-5-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@redhat.com>

[
 Fixed warnings for:
   kernel/trace/trace.c: In function '__tracing_open':
   kernel/trace/trace.c:2418:11: warning: unused variable 'ret' [-Wunused-variable]
   kernel/trace/trace.c:2417:19: warning: unused variable 'm' [-Wunused-variable]
]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

When CONFIG_DYNAMIC_FTRACE is not set, some archs (ARM) test
the variable function_trace_function to determine if it should
call the function tracer. If it is not set to ftrace_stub, then
it will call the function and return, and not call the function
graph tracer.

But some of these archs (ARM) do not have the assembly code
to test if function tracing is enabled or not (quick stop of tracing)
and it calls the helper routine ftrace_test_stop_func() instead.

If function tracer is enabled and then disabled, the variable
ftrace_trace_function is still set to the helper routine
ftrace_test_stop_func(), and not to ftrace_stub. This will
prevent the function graph tracer from ever running.

Output before patch
/debug/tracing # echo function > current_tracer
/debug/tracing # echo function_graph > current_tracer
/debug/tracing # cat trace

Output after patch
/debug/tracing # echo function > current_tracer
/debug/tracing # echo function_graph > current_tracer
/debug/tracing # cat trace
0) ! 253.375 us | } /* irq_enter */
0) | generic_handle_irq() {
0) | handle_fasteoi_irq() {
0) 9.208 us | _raw_spin_lock();
0) | handle_irq_event() {
0) | handle_irq_event_percpu() {
Signed-off-by: NRajesh Bhagat <rajesh.lnx@gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Adding support to filter function trace event via perf
interface. It is now possible to use filter interface
in the perf tool like:

  perf record -e ftrace:function --filter="(ip == mm_*)" ls

The filter syntax is restricted to the the 'ip' field only,
and following operators are accepted '==' '!=' '||', ending
up with the filter strings like:

  ip == f1[, ]f2 ... || ip != f3[, ]f4 ...

with comma ',' or space ' ' as a function separator. If the
space ' ' is used as a separator, the right side of the
assignment needs to be enclosed in double quotes '"', e.g.:

  perf record -e ftrace:function --filter '(ip == do_execve,sys_*,ext*)' ls
  perf record -e ftrace:function --filter '(ip == "do_execve,sys_*,ext*")' ls
  perf record -e ftrace:function --filter '(ip == "do_execve sys_* ext*")' ls

The '==' operator adds trace filter with same effect as would
be added via set_ftrace_filter file.

The '!=' operator adds trace filter with same effect as would
be added via set_ftrace_notrace file.

The right side of the '!=', '==' operators is list of functions
or regexp. to be added to filter separated by space.

The '||' operator is used for connecting multiple filter definitions
together. It is possible to have more than one '==' and '!='
operators within one filter string.

Link: http://lkml.kernel.org/r/1329317514-8131-8-git-send-email-jolsa@redhat.comSigned-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Adding a way to temporarily enable/disable ftrace_ops. The change
follows the same way as 'global' ftrace_ops are done.

Introducing 2 global ftrace_ops - control_ops and ftrace_control_list
which take over all ftrace_ops registered with FTRACE_OPS_FL_CONTROL
flag. In addition new per cpu flag called 'disabled' is also added to
ftrace_ops to provide the control information for each cpu.

When ftrace_ops with FTRACE_OPS_FL_CONTROL is registered, it is
set as disabled for all cpus.

The ftrace_control_list contains all the registered 'control' ftrace_ops.
The control_ops provides function which iterates ftrace_control_list
and does the check for 'disabled' flag on current cpu.

Adding 3 inline functions:
  ftrace_function_local_disable/ftrace_function_local_enable
  - enable/disable the ftrace_ops on current cpu
  ftrace_function_local_disabled
  - get disabled ftrace_ops::disabled value for current cpu

Link: http://lkml.kernel.org/r/1329317514-8131-2-git-send-email-jolsa@redhat.comAcked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Link: http://lkml.kernel.org/r/1322600880.1534.347.camel@localhost.localdomainSigned-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently the ftrace_set_filter and ftrace_set_notrace functions
do not return any return code. So there's no way for ftrace_ops
user to tell wether the filter was correctly applied.

The set_ftrace_filter interface returns error in case the filter
did not match:

  # echo krava > set_ftrace_filter
  bash: echo: write error: Invalid argument

Changing both ftrace_set_filter and ftrace_set_notrace functions
to return zero if the filter was applied correctly or -E* values
in case of error.

Link: http://lkml.kernel.org/r/1325495060-6402-2-git-send-email-jolsa@redhat.comAcked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Change set_ftrace_early_filter() to ftrace_set_early_filter()
and make it a global function. This will allow other subsystems
in the kernel to be able to enable function tracing at start
up and reuse the ftrace function parsing code.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The set_ftrace_filter shows "hashed" functions, which are functions
that are added with operations to them (like traceon and traceoff).

As other subsystems may be able to show what functions they are
using for function tracing, the hash items should no longer
be shown just because the FILTER flag is set. As they have nothing
to do with other subsystems filters.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The function tracer is set up to allow any other subsystem (like perf)
to use it. Ftrace already has a way to list what functions are enabled
by the global_ops. It would be very helpful to let other users of
the function tracer to be able to use the same code.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

There are two types of hashes in the ftrace_ops; one type
is the filter_hash and the other is the notrace_hash. Either
one may be null, meaning it has no elements. But when elements
are added, the hash is allocated.

Throughout the code, a check needs to be made to see if a hash
exists or the hash has elements, but the check if the hash exists
is usually missing causing the possible "NULL pointer dereference bug".

Add a helper routine called "ftrace_hash_empty()" that returns
true if the hash doesn't exist or its count is zero. As they mean
the same thing.
Last-bug-reported-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

When disabling the "notrace" records, that means we want to trace them.
If the notrace_hash is zero, it means that we want to trace all
records. But to disable a zero notrace_hash means nothing.

The check for the notrace_hash count was incorrect with:

	if (hash && !hash->count)
		return

With the correct comment above it that states that we do nothing
if the notrace_hash has zero count. But !hash also means that
the notrace hash has zero count. I think this was done to
protect against dereferencing NULL. But if !hash is true, then
we go through the following loop without doing a single thing.

Fix it to:

	if (!hash || !hash->count)
		return;
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Now that each set of pages in the function list are sorted by
ip, we can use bsearch to find a record within each set of pages.
This speeds up the ftrace_location() function by magnitudes.

For archs (like x86) that need to add a breakpoint at every function
that will be converted from a nop to a callback and vice versa,
the breakpoint callback needs to know if the breakpoint was for
ftrace or not. It requires finding the breakpoint ip within the
records. Doing a linear search is extremely inefficient. It is
a must to be able to do a fast binary search to find these locations.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Sort records by ip locations of the ftrace mcount calls on each of the
set of pages in the function list. This helps in localizing cache
usuage when updating the function locations, as well as gives us
the ability to quickly find an ip location in the list.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As new functions come in to be initalized from mcount to nop,
they are done by groups of pages. Whether it is the core kernel
or a module. There's no need to keep track of these on a per record
basis.

At startup, and as any module is loaded, the functions to be
traced are stored in a group of pages and added to the function
list at the end. We just need to keep a pointer to the first
page of the list that was added, and use that to know where to
start on the list for initializing functions.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Allocate the mcount record pages as a group of pages as big
as can be allocated and waste no more than a single page.

Grouping the mcount pages as much as possible helps with cache
locality, as we do not need to redirect with descriptors as we
cross from page to page. It also allows us to do more with the
records later on (sort them with bigger benefits).
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Records that are added to the function trace table are
permanently there, except for modules. By separating out the
modules to their own pages that can be freed in one shot
we can remove the "freed" flag and simplify some of the record
management.

Another benefit of doing this is that we can also move the
records around; sort them.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The stop machine method to modify all functions in the kernel
(some 20,000 of them) is the safest way to do so across all archs.
But some archs may not need this big hammer approach to modify code
on SMP machines, and can simply just update the code it needs.

Adding a weak function arch_ftrace_update_code() that now does the
stop machine, will also let any arch override this method.

If the arch needs to check the system and then decide if it can
avoid stop machine, it can still call ftrace_run_stop_machine() to
use the old method.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Multiple users of the function tracer can register their functions
with the ftrace_ops structure. The accounting within ftrace will
update the counter on each function record that is being traced.
When the ftrace_ops filtering adds or removes functions, the
function records will be updated accordingly if the ftrace_ops is
still registered.

When a ftrace_ops is removed, the counter of the function records,
that the ftrace_ops traces, are decremented. When they reach zero
the functions that they represent are modified to stop calling the
mcount code.

When changes are made, the code is updated via stop_machine() with
a command passed to the function to tell it what to do. There is an
ENABLE and DISABLE command that tells the called function to enable
or disable the functions. But the ENABLE is really a misnomer as it
should just update the records, as records that have been enabled
and now have a count of zero should be disabled.

The DISABLE command is used to disable all functions regardless of
their counter values. This is the big off switch and is not the
complement of the ENABLE command.

To make matters worse, when a ftrace_ops is unregistered and there
is another ftrace_ops registered, neither the DISABLE nor the
ENABLE command are set when calling into the stop_machine() function
and the records will not be updated to match their counter. A command
is passed to that function that will update the mcount code to call
the registered callback directly if it is the only one left. This
means that the ftrace_ops that is still registered will have its callback
called by all functions that have been set for it as well as the ftrace_ops
that was just unregistered.

Here's a way to trigger this bug. Compile the kernel with
CONFIG_FUNCTION_PROFILER set and with CONFIG_FUNCTION_GRAPH not set:

 CONFIG_FUNCTION_PROFILER=y
 # CONFIG_FUNCTION_GRAPH is not set

This will force the function profiler to use the function tracer instead
of the function graph tracer.

  # cd /sys/kernel/debug/tracing
  # echo schedule > set_ftrace_filter
  # echo function > current_tracer
  # cat set_ftrace_filter
 schedule
  # cat trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 692/68108025   #P:4
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
      kworker/0:2-909   [000] ....   531.235574: schedule <-worker_thread
           <idle>-0     [001] .N..   531.235575: schedule <-cpu_idle
      kworker/0:2-909   [000] ....   531.235597: schedule <-worker_thread
             sshd-2563  [001] ....   531.235647: schedule <-schedule_hrtimeout_range_clock

  # echo 1 > function_profile_enabled
  # echo 0 > function_porfile_enabled
  # cat set_ftrace_filter
 schedule
  # cat trace
 # tracer: function
 #
 # entries-in-buffer/entries-written: 159701/118821262   #P:4
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
           <idle>-0     [002] ...1   604.870655: local_touch_nmi <-cpu_idle
           <idle>-0     [002] d..1   604.870655: enter_idle <-cpu_idle
           <idle>-0     [002] d..1   604.870656: atomic_notifier_call_chain <-enter_idle
           <idle>-0     [002] d..1   604.870656: __atomic_notifier_call_chain <-atomic_notifier_call_chain

The same problem could have happened with the trace_probe_ops,
but they are modified with the set_frace_filter file which does the
update at closure of the file.

The simple solution is to change ENABLE to UPDATE and call it every
time an ftrace_ops is unregistered.

Link: http://lkml.kernel.org/r/1323105776-26961-3-git-send-email-jolsa@redhat.com

Cc: stable@vger.kernel.org # 3.0+
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If the set_ftrace_filter is cleared by writing just whitespace to
it, then the filter hash refcounts will be decremented but not
updated. This causes two bugs:

1) No functions will be enabled for tracing when they all should be

2) If the users clears the set_ftrace_filter twice, it will crash ftrace:

------------[ cut here ]------------
WARNING: at /home/rostedt/work/git/linux-trace.git/kernel/trace/ftrace.c:1384 __ftrace_hash_rec_update.part.27+0x157/0x1a7()
Modules linked in:
Pid: 2330, comm: bash Not tainted 3.1.0-test+ #32
Call Trace:
 [<ffffffff81051828>] warn_slowpath_common+0x83/0x9b
 [<ffffffff8105185a>] warn_slowpath_null+0x1a/0x1c
 [<ffffffff810ba362>] __ftrace_hash_rec_update.part.27+0x157/0x1a7
 [<ffffffff810ba6e8>] ? ftrace_regex_release+0xa7/0x10f
 [<ffffffff8111bdfe>] ? kfree+0xe5/0x115
 [<ffffffff810ba51e>] ftrace_hash_move+0x2e/0x151
 [<ffffffff810ba6fb>] ftrace_regex_release+0xba/0x10f
 [<ffffffff8112e49a>] fput+0xfd/0x1c2
 [<ffffffff8112b54c>] filp_close+0x6d/0x78
 [<ffffffff8113a92d>] sys_dup3+0x197/0x1c1
 [<ffffffff8113a9a6>] sys_dup2+0x4f/0x54
 [<ffffffff8150cac2>] system_call_fastpath+0x16/0x1b
---[ end trace 77a3a7ee73794a02 ]---

Link: http://lkml.kernel.org/r/20111101141420.GA4918@debianReported-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

A forced undef of a config value was used for testing and was
accidently left in during the final commit. This causes x86 to
run slower than needed while running function tracing as well
as causes the function graph selftest to fail when DYNMAIC_FTRACE
is not set. This is because the code in MCOUNT expects the ftrace
code to be processed with the config value set that happened to
be forced not set.

The forced config option was left in by:
    commit 6331c28c
    ftrace: Fix dynamic selftest failure on some archs

Link: http://lkml.kernel.org/r/20111102150255.GA6973@debian

Cc: stable@vger.kernel.org
Reported-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If the set_ftrace_filter is cleared by writing just whitespace to
it, then the filter hash refcounts will be decremented but not
updated. This causes two bugs:

1) No functions will be enabled for tracing when they all should be

2) If the users clears the set_ftrace_filter twice, it will crash ftrace:

------------[ cut here ]------------
WARNING: at /home/rostedt/work/git/linux-trace.git/kernel/trace/ftrace.c:1384 __ftrace_hash_rec_update.part.27+0x157/0x1a7()
Modules linked in:
Pid: 2330, comm: bash Not tainted 3.1.0-test+ #32
Call Trace:
 [<ffffffff81051828>] warn_slowpath_common+0x83/0x9b
 [<ffffffff8105185a>] warn_slowpath_null+0x1a/0x1c
 [<ffffffff810ba362>] __ftrace_hash_rec_update.part.27+0x157/0x1a7
 [<ffffffff810ba6e8>] ? ftrace_regex_release+0xa7/0x10f
 [<ffffffff8111bdfe>] ? kfree+0xe5/0x115
 [<ffffffff810ba51e>] ftrace_hash_move+0x2e/0x151
 [<ffffffff810ba6fb>] ftrace_regex_release+0xba/0x10f
 [<ffffffff8112e49a>] fput+0xfd/0x1c2
 [<ffffffff8112b54c>] filp_close+0x6d/0x78
 [<ffffffff8113a92d>] sys_dup3+0x197/0x1c1
 [<ffffffff8113a9a6>] sys_dup2+0x4f/0x54
 [<ffffffff8150cac2>] system_call_fastpath+0x16/0x1b
---[ end trace 77a3a7ee73794a02 ]---

Link: http://lkml.kernel.org/r/20111101141420.GA4918@debianReported-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

A forced undef of a config value was used for testing and was
accidently left in during the final commit. This causes x86 to
run slower than needed while running function tracing as well
as causes the function graph selftest to fail when DYNMAIC_FTRACE
is not set. This is because the code in MCOUNT expects the ftrace
code to be processed with the config value set that happened to
be forced not set.

The forced config option was left in by:
    commit 6331c28c
    ftrace: Fix dynamic selftest failure on some archs

Link: http://lkml.kernel.org/r/20111102150255.GA6973@debian

Cc: stable@vger.kernel.org
Reported-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

These files are doing things like module_put and try_module_get
so they need to call out the module.h for explicit inclusion,
rather than getting it via <linux/device.h> which we ideally want
to remove the module.h inclusion from.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>