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<title>user/sven/linux.git/include/linux/ftrace.h, branch v3.16.3</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.16.3</id>
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<updated>2014-06-09T23:39:15Z</updated>
<entry>
<title>Merge tag 'trace-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2014-06-09T23:39:15Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-06-09T23:39:15Z</published>
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<id>urn:sha1:214b93132023cc9305d5801add812515bea4d7d0</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:
 "Lots of tweaks, small fixes, optimizations, and some helper functions
  to help out the rest of the kernel to ease their use of trace events.

  The big change for this release is the allowing of other tracers, such
  as the latency tracers, to be used in the trace instances and allow
  for function or function graph tracing to be in the top level
  simultaneously"

* tag 'trace-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  tracing: Fix memory leak on instance deletion
  tracing: Fix leak of ring buffer data when new instances creation fails
  tracing/kprobes: Avoid self tests if tracing is disabled on boot up
  tracing: Return error if ftrace_trace_arrays list is empty
  tracing: Only calculate stats of tracepoint benchmarks for 2^32 times
  tracing: Convert stddev into u64 in tracepoint benchmark
  tracing: Introduce saved_cmdlines_size file
  tracing: Add __get_dynamic_array_len() macro for trace events
  tracing: Remove unused variable in trace_benchmark
  tracing: Eliminate double free on failure of allocation on boot up
  ftrace/x86: Call text_ip_addr() instead of the duplicated code
  tracing: Print max callstack on stacktrace bug
  tracing: Move locking of trace_cmdline_lock into start/stop seq calls
  tracing: Try again for saved cmdline if failed due to locking
  tracing: Have saved_cmdlines use the seq_read infrastructure
  tracing: Add tracepoint benchmark tracepoint
  tracing: Print nasty banner when trace_printk() is in use
  tracing: Add funcgraph_tail option to print function name after closing braces
  tracing: Eliminate duplicate TRACE_GRAPH_PRINT_xx defines
  tracing: Add __bitmask() macro to trace events to cpumasks and other bitmasks
  ...
</content>
</entry>
<entry>
<title>ftrace: Make CALLER_ADDRx macros more generic</title>
<updated>2014-05-21T07:10:32Z</updated>
<author>
<name>AKASHI Takahiro</name>
<email>takahiro.akashi@linaro.org</email>
</author>
<published>2014-05-20T11:31:04Z</published>
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<id>urn:sha1:eed542d6962ba33a689b4007a389f466e407bd74</id>
<content type='text'>
Most archs with HAVE_ARCH_CALLER_ADDR have pretty much the same
definitions of CALLER_ADDRx(n). Instead of duplicating the code for all
the archs, define a ftrace_return_address0() and
ftrace_return_address(n) that can be overwritten by the archs if they
need to do something different. Instead of 7 macros in every arch, we
now only have at most 2 (and actually only 1 as
ftrace_return_address0() should be the same for all archs).

The CALLER_ADDRx(n) will now be defined in linux/ftrace.h and use the
ftrace_return_address*(n?) macros. This removes a lot of the duplicate
code.

Link: http://lkml.kernel.org/p/1400585464-30333-1-git-send-email-takahiro.akashi@linaro.org

Signed-off-by: AKASHI Takahiro &lt;takahiro.akashi@linaro.org&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Remove FTRACE_UPDATE_MODIFY_CALL_REGS flag</title>
<updated>2014-05-14T15:37:30Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-05-07T20:09:49Z</published>
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<id>urn:sha1:f1b2f2bd5821c6ab7feed2e133343dd54b212ed9</id>
<content type='text'>
As the decision to what needs to be done (converting a call to the
ftrace_caller to ftrace_caller_regs or to convert from ftrace_caller_regs
to ftrace_caller) can easily be determined from the rec-&gt;flags of
FTRACE_FL_REGS and FTRACE_FL_REGS_EN, there's no need to have the
ftrace_check_record() return either a UPDATE_MODIFY_CALL_REGS or a
UPDATE_MODIFY_CALL. Just he latter is enough. This added flag causes
more complexity than is required. Remove it.

Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global</title>
<updated>2014-05-14T15:37:29Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-05-07T01:34:14Z</published>
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<id>urn:sha1:7413af1fb70e7efa6dbc7f27663e7a5126b3aa33</id>
<content type='text'>
Move and rename get_ftrace_addr() and get_ftrace_addr_old() to
ftrace_get_addr_new() and ftrace_get_addr_curr() respectively.

This moves these two helper functions in the generic code out from
the arch specific code, and renames them to have a better generic
name. This will allow other archs to use them as well as makes it
a bit easier to work on getting separate trampolines for different
functions.

ftrace_get_addr_new() returns the trampoline address that the mcount
call address will be converted to.

ftrace_get_addr_curr() returns the trampoline address of what the
mcount call address currently jumps to.

Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace/module: Hardcode ftrace_module_init() call into load_module()</title>
<updated>2014-04-28T14:37:21Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-04-24T14:40:12Z</published>
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<id>urn:sha1:a949ae560a511fe4e3adf48fa44fefded93e5c2b</id>
<content type='text'>
A race exists between module loading and enabling of function tracer.

	CPU 1				CPU 2
	-----				-----
  load_module()
   module-&gt;state = MODULE_STATE_COMING

				register_ftrace_function()
				 mutex_lock(&amp;ftrace_lock);
				 ftrace_startup()
				  update_ftrace_function();
				   ftrace_arch_code_modify_prepare()
				    set_all_module_text_rw();
				   &lt;enables-ftrace&gt;
				    ftrace_arch_code_modify_post_process()
				     set_all_module_text_ro();

				[ here all module text is set to RO,
				  including the module that is
				  loading!! ]

   blocking_notifier_call_chain(MODULE_STATE_COMING);
    ftrace_init_module()

     [ tries to modify code, but it's RO, and fails!
       ftrace_bug() is called]

When this race happens, ftrace_bug() will produces a nasty warning and
all of the function tracing features will be disabled until reboot.

The simple solution is to treate module load the same way the core
kernel is treated at boot. To hardcode the ftrace function modification
of converting calls to mcount into nops. This is done in init/main.c
there's no reason it could not be done in load_module(). This gives
a better control of the changes and doesn't tie the state of the
module to its notifiers as much. Ftrace is special, it needs to be
treated as such.

The reason this would work, is that the ftrace_module_init() would be
called while the module is in MODULE_STATE_UNFORMED, which is ignored
by the set_all_module_text_ro() call.

Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com

Reported-by: Takao Indoh &lt;indou.takao@jp.fujitsu.com&gt;
Acked-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: stable@vger.kernel.org # 2.6.38+
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Remove global function list and call function directly</title>
<updated>2014-04-21T17:59:25Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-01-10T22:01:58Z</published>
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<id>urn:sha1:4104d326b670c2b66f575d2004daa28b2d1b4c8d</id>
<content type='text'>
Instead of having a list of global functions that are called,
as only one global function is allow to be enabled at a time, there's
no reason to have a list.

Instead, simply have all the users of the global ops, use the global ops
directly, instead of registering their own ftrace_ops. Just switch what
function is used before enabling the function tracer.

This removes a lot of code as well as the complexity involved with it.

Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Constify ftrace_text_reserved</title>
<updated>2014-03-12T02:52:43Z</updated>
<author>
<name>Sasha Levin</name>
<email>sasha.levin@oracle.com</email>
</author>
<published>2013-01-09T23:09:20Z</published>
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<id>urn:sha1:d88471cb8b17a72b1edf5ab62e1704d78373c066</id>
<content type='text'>
Link: http://lkml.kernel.org/r/1357772960-4436-5-git-send-email-sasha.levin@oracle.com

Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Remove freelist from struct dyn_ftrace</title>
<updated>2014-03-07T15:06:14Z</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2014-02-24T19:00:00Z</published>
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<id>urn:sha1:a762782d780b341b1836489692190d26be624ed7</id>
<content type='text'>
The 'freelist' member was introduced to 'struct dyn_ftrace' in commit
ee000b7f9fe429d2470c674ccec8d344f6789e0d (tracing: use union for
multi-usages field), but the use of this member was later removed in
3208230983a0ee3d95be22d463257e530c684956 (ftrace: Remove usage of
"freed" records). Remove also the 'freelist' member now.

Link: http://lkml.kernel.org/r/1393268401-24379-5-git-send-email-jslaby@suse.cz

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Do not pass data to ftrace_dyn_arch_init</title>
<updated>2014-03-07T15:06:14Z</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2014-02-24T18:59:59Z</published>
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<id>urn:sha1:3a36cb11ca65cd6804972eaf1000378ba4384ea7</id>
<content type='text'>
As the data parameter is not really used by any ftrace_dyn_arch_init,
remove that from ftrace_dyn_arch_init. This also removes the addr
local variable from ftrace_init which is now unused.

Note the documentation was imprecise as it did not suggest to set
(*data) to 0.

Link: http://lkml.kernel.org/r/1393268401-24379-4-git-send-email-jslaby@suse.cz

Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: linux-arch@vger.kernel.org
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>ftrace: Allow for function tracing instance to filter functions</title>
<updated>2014-02-20T17:29:07Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-01-10T21:17:45Z</published>
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<id>urn:sha1:591dffdade9f07692a7dd3ed16830ec24e901ece</id>
<content type='text'>
Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance
directories to let users filter of functions to trace for the given instance.

Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
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