<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel, branch v3.17-rc2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2014-08-25T22:11:53+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-08-25T22:11:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=01e9982ab39a1279adcb5d8741fd912870dc3d4b'/>
<id>01e9982ab39a1279adcb5d8741fd912870dc3d4b</id>
<content type='text'>
Pull fix for ftrace function tracer/profiler conflict from Steven Rostedt:
 "The rewrite of the ftrace code that makes it possible to allow for
  separate trampolines had a design flaw with the interaction between
  the function and function_graph tracers.

  The main flaw was the simplification of the use of multiple tracers
  having the same filter (like function and function_graph, that use the
  set_ftrace_filter file to filter their code).  The design assumed that
  the two tracers could never run simultaneously as only one tracer can
  be used at a time.  The problem with this assumption was that the
  function profiler could be implemented on top of the function graph
  tracer, and the function profiler could run at the same time as the
  function tracer.  This caused the assumption to be broken and when
  ftrace detected this failed assumpiton it would spit out a nasty
  warning and shut itself down.

  Instead of using a single ftrace_ops that switches between the
  function and function_graph callbacks, the two tracers can again use
  their own ftrace_ops.  But instead of having a complex hierarchy of
  ftrace_ops, the filter fields are placed in its own structure and the
  ftrace_ops can carefully use the same filter.  This change took a bit
  to be able to allow for this and currently only the global_ops can
  share the same filter, but this new design can easily be modified to
  allow for any ftrace_ops to share its filter with another ftrace_ops.

  The first four patches deal with the change of allowing the ftrace_ops
  to share the filter (and this needs to go to 3.16 as well).

  The fifth patch fixes a bug that was also caused by the new changes
  but only for archs other than x86, and only if those archs implement a
  direct call to the function_graph tracer which they do not do yet but
  will in the future.  It does not need to go to stable, but needs to be
  fixed before the other archs update their code to allow direct calls
  to the function_graph trampoline"

* tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Use current addr when converting to nop in __ftrace_replace_code()
  ftrace: Fix function_profiler and function tracer together
  ftrace: Fix up trampoline accounting with looping on hash ops
  ftrace: Update all ftrace_ops for a ftrace_hash_ops update
  ftrace: Allow ftrace_ops to use the hashes from other ops
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull fix for ftrace function tracer/profiler conflict from Steven Rostedt:
 "The rewrite of the ftrace code that makes it possible to allow for
  separate trampolines had a design flaw with the interaction between
  the function and function_graph tracers.

  The main flaw was the simplification of the use of multiple tracers
  having the same filter (like function and function_graph, that use the
  set_ftrace_filter file to filter their code).  The design assumed that
  the two tracers could never run simultaneously as only one tracer can
  be used at a time.  The problem with this assumption was that the
  function profiler could be implemented on top of the function graph
  tracer, and the function profiler could run at the same time as the
  function tracer.  This caused the assumption to be broken and when
  ftrace detected this failed assumpiton it would spit out a nasty
  warning and shut itself down.

  Instead of using a single ftrace_ops that switches between the
  function and function_graph callbacks, the two tracers can again use
  their own ftrace_ops.  But instead of having a complex hierarchy of
  ftrace_ops, the filter fields are placed in its own structure and the
  ftrace_ops can carefully use the same filter.  This change took a bit
  to be able to allow for this and currently only the global_ops can
  share the same filter, but this new design can easily be modified to
  allow for any ftrace_ops to share its filter with another ftrace_ops.

  The first four patches deal with the change of allowing the ftrace_ops
  to share the filter (and this needs to go to 3.16 as well).

  The fifth patch fixes a bug that was also caused by the new changes
  but only for archs other than x86, and only if those archs implement a
  direct call to the function_graph tracer which they do not do yet but
  will in the future.  It does not need to go to stable, but needs to be
  fixed before the other archs update their code to allow direct calls
  to the function_graph trampoline"

* tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Use current addr when converting to nop in __ftrace_replace_code()
  ftrace: Fix function_profiler and function tracer together
  ftrace: Fix up trampoline accounting with looping on hash ops
  ftrace: Update all ftrace_ops for a ftrace_hash_ops update
  ftrace: Allow ftrace_ops to use the hashes from other ops
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-08-24T23:16:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-08-24T23:16:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=44744bb344abe032b387d361209038d2956e8c75'/>
<id>44744bb344abe032b387d361209038d2956e8c75</id>
<content type='text'>
Pull perf fixes from Ingo Molnar:
 "A kprobes and a perf compat ioctl fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Handle compat ioctl
  kprobes: Skip kretprobe hit in NMI context to avoid deadlock
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fixes from Ingo Molnar:
 "A kprobes and a perf compat ioctl fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Handle compat ioctl
  kprobes: Skip kretprobe hit in NMI context to avoid deadlock
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Use current addr when converting to nop in __ftrace_replace_code()</title>
<updated>2014-08-23T01:04:35+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-08-18T00:59:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=39b5552cd5090d4c210d278cd2732f493075f033'/>
<id>39b5552cd5090d4c210d278cd2732f493075f033</id>
<content type='text'>
In __ftrace_replace_code(), when converting the call to a nop in a function
it needs to compare against the "curr" (current) value of the ftrace ops, and
not the "new" one. It currently does not affect x86 which is the only arch
to do the trampolines with function graph tracer, but when other archs that do
depend on this code implement the function graph trampoline, it can crash.

Here's an example when ARM uses the trampolines (in the future):

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 9 at kernel/trace/ftrace.c:1716 ftrace_bug+0x17c/0x1f4()
 Modules linked in: omap_rng rng_core ipv6
 CPU: 0 PID: 9 Comm: migration/0 Not tainted 3.16.0-test-10959-gf0094b28f303-dirty #52
 [&lt;c02188f4&gt;] (unwind_backtrace) from [&lt;c021343c&gt;] (show_stack+0x20/0x24)
 [&lt;c021343c&gt;] (show_stack) from [&lt;c095a674&gt;] (dump_stack+0x78/0x94)
 [&lt;c095a674&gt;] (dump_stack) from [&lt;c02532a0&gt;] (warn_slowpath_common+0x7c/0x9c)
 [&lt;c02532a0&gt;] (warn_slowpath_common) from [&lt;c02532ec&gt;] (warn_slowpath_null+0x2c/0x34)
 [&lt;c02532ec&gt;] (warn_slowpath_null) from [&lt;c02cbac4&gt;] (ftrace_bug+0x17c/0x1f4)
 [&lt;c02cbac4&gt;] (ftrace_bug) from [&lt;c02cc44c&gt;] (ftrace_replace_code+0x80/0x9c)
 [&lt;c02cc44c&gt;] (ftrace_replace_code) from [&lt;c02cc658&gt;] (ftrace_modify_all_code+0xb8/0x164)
 [&lt;c02cc658&gt;] (ftrace_modify_all_code) from [&lt;c02cc718&gt;] (__ftrace_modify_code+0x14/0x1c)
 [&lt;c02cc718&gt;] (__ftrace_modify_code) from [&lt;c02c7244&gt;] (multi_cpu_stop+0xf4/0x134)
 [&lt;c02c7244&gt;] (multi_cpu_stop) from [&lt;c02c6e90&gt;] (cpu_stopper_thread+0x54/0x130)
 [&lt;c02c6e90&gt;] (cpu_stopper_thread) from [&lt;c0271cd4&gt;] (smpboot_thread_fn+0x1ac/0x1bc)
 [&lt;c0271cd4&gt;] (smpboot_thread_fn) from [&lt;c026ddf0&gt;] (kthread+0xe0/0xfc)
 [&lt;c026ddf0&gt;] (kthread) from [&lt;c020f318&gt;] (ret_from_fork+0x14/0x20)
 ---[ end trace dc9ce72c5b617d8f ]---
[   65.047264] ftrace failed to modify [&lt;c0208580&gt;] asm_do_IRQ+0x10/0x1c
[   65.054070]  actual: 85:1b:00:eb

Fixes: 7413af1fb70e7 "ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global"
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In __ftrace_replace_code(), when converting the call to a nop in a function
it needs to compare against the "curr" (current) value of the ftrace ops, and
not the "new" one. It currently does not affect x86 which is the only arch
to do the trampolines with function graph tracer, but when other archs that do
depend on this code implement the function graph trampoline, it can crash.

Here's an example when ARM uses the trampolines (in the future):

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 9 at kernel/trace/ftrace.c:1716 ftrace_bug+0x17c/0x1f4()
 Modules linked in: omap_rng rng_core ipv6
 CPU: 0 PID: 9 Comm: migration/0 Not tainted 3.16.0-test-10959-gf0094b28f303-dirty #52
 [&lt;c02188f4&gt;] (unwind_backtrace) from [&lt;c021343c&gt;] (show_stack+0x20/0x24)
 [&lt;c021343c&gt;] (show_stack) from [&lt;c095a674&gt;] (dump_stack+0x78/0x94)
 [&lt;c095a674&gt;] (dump_stack) from [&lt;c02532a0&gt;] (warn_slowpath_common+0x7c/0x9c)
 [&lt;c02532a0&gt;] (warn_slowpath_common) from [&lt;c02532ec&gt;] (warn_slowpath_null+0x2c/0x34)
 [&lt;c02532ec&gt;] (warn_slowpath_null) from [&lt;c02cbac4&gt;] (ftrace_bug+0x17c/0x1f4)
 [&lt;c02cbac4&gt;] (ftrace_bug) from [&lt;c02cc44c&gt;] (ftrace_replace_code+0x80/0x9c)
 [&lt;c02cc44c&gt;] (ftrace_replace_code) from [&lt;c02cc658&gt;] (ftrace_modify_all_code+0xb8/0x164)
 [&lt;c02cc658&gt;] (ftrace_modify_all_code) from [&lt;c02cc718&gt;] (__ftrace_modify_code+0x14/0x1c)
 [&lt;c02cc718&gt;] (__ftrace_modify_code) from [&lt;c02c7244&gt;] (multi_cpu_stop+0xf4/0x134)
 [&lt;c02c7244&gt;] (multi_cpu_stop) from [&lt;c02c6e90&gt;] (cpu_stopper_thread+0x54/0x130)
 [&lt;c02c6e90&gt;] (cpu_stopper_thread) from [&lt;c0271cd4&gt;] (smpboot_thread_fn+0x1ac/0x1bc)
 [&lt;c0271cd4&gt;] (smpboot_thread_fn) from [&lt;c026ddf0&gt;] (kthread+0xe0/0xfc)
 [&lt;c026ddf0&gt;] (kthread) from [&lt;c020f318&gt;] (ret_from_fork+0x14/0x20)
 ---[ end trace dc9ce72c5b617d8f ]---
[   65.047264] ftrace failed to modify [&lt;c0208580&gt;] asm_do_IRQ+0x10/0x1c
[   65.054070]  actual: 85:1b:00:eb

Fixes: 7413af1fb70e7 "ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global"
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Fix function_profiler and function tracer together</title>
<updated>2014-08-23T01:04:34+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-08-15T21:18:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5f151b240192a1557119d5375af71efc26825bc8'/>
<id>5f151b240192a1557119d5375af71efc26825bc8</id>
<content type='text'>
The latest rewrite of ftrace removed the separate ftrace_ops of
the function tracer and the function graph tracer and had them
share the same ftrace_ops. This simplified the accounting by removing
the multiple layers of functions called, where the global_ops func
would call a special list that would iterate over the other ops that
were registered within it (like function and function graph), which
itself was registered to the ftrace ops list of all functions
currently active. If that sounds confusing, the code that implemented
it was also confusing and its removal is a good thing.

The problem with this change was that it assumed that the function
and function graph tracer can never be used at the same time.
This is mostly true, but there is an exception. That is when the
function profiler uses the function graph tracer to profile.
The function profiler can be activated the same time as the function
tracer, and this breaks the assumption and the result is that ftrace
will crash (it detects the error and shuts itself down, it does not
cause a kernel oops).

To solve this issue, a previous change allowed the hash tables
for the functions traced by a ftrace_ops to be a pointer and let
multiple ftrace_ops share the same hash. This allows the function
and function_graph tracer to have separate ftrace_ops, but still
share the hash, which is what is done.

Now the function and function graph tracers have separate ftrace_ops
again, and the function tracer can be run while the function_profile
is active.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The latest rewrite of ftrace removed the separate ftrace_ops of
the function tracer and the function graph tracer and had them
share the same ftrace_ops. This simplified the accounting by removing
the multiple layers of functions called, where the global_ops func
would call a special list that would iterate over the other ops that
were registered within it (like function and function graph), which
itself was registered to the ftrace ops list of all functions
currently active. If that sounds confusing, the code that implemented
it was also confusing and its removal is a good thing.

The problem with this change was that it assumed that the function
and function graph tracer can never be used at the same time.
This is mostly true, but there is an exception. That is when the
function profiler uses the function graph tracer to profile.
The function profiler can be activated the same time as the function
tracer, and this breaks the assumption and the result is that ftrace
will crash (it detects the error and shuts itself down, it does not
cause a kernel oops).

To solve this issue, a previous change allowed the hash tables
for the functions traced by a ftrace_ops to be a pointer and let
multiple ftrace_ops share the same hash. This allows the function
and function_graph tracer to have separate ftrace_ops, but still
share the hash, which is what is done.

Now the function and function graph tracers have separate ftrace_ops
again, and the function tracer can be run while the function_profile
is active.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Fix up trampoline accounting with looping on hash ops</title>
<updated>2014-08-22T19:24:12+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-08-21T03:57:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bce0b6c51ac76fc0e763262a6c2a9d05e486f0d8'/>
<id>bce0b6c51ac76fc0e763262a6c2a9d05e486f0d8</id>
<content type='text'>
Now that a ftrace_hash can be shared by multiple ftrace_ops, they can dec
the rec-&gt;flags by more than once (one per those that share the ftrace_hash).
This means that the tramp_hash may not have a hash item when it was added.

For example, if two ftrace_ops share a hash for a ftrace record, and the
first ops has a trampoline, when it adds itself it will set the rec-&gt;flags
TRAMP flag and increments its nr_trampolines counter. When the second ops
is added, it must clear that tramp flag but also decrement the other ops
that shares its hash. As the update to the function callbacks has not yet
been performed, the other ops will not have the tramp hash set yet and it
can not be used to know to decrement its nr_trampolines.

Luckily, the tramp_hash does not need to be used. As the ftrace_mutex is
held, a ops with a trampoline to a record during an update of another ops
that shares the record will have its func_hash pointing to it. Since a
trampoline can only be set for a record if only one ops is attached to it,
we can just check if the record has a trampoline (the FTRACE_FL_TRAMP flag
is set) and then find the ops that has this record in its hashes.

Also added some output to help debug when things go wrong.

Cc: stable@vger.kernel.org # 3.16+ (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that a ftrace_hash can be shared by multiple ftrace_ops, they can dec
the rec-&gt;flags by more than once (one per those that share the ftrace_hash).
This means that the tramp_hash may not have a hash item when it was added.

For example, if two ftrace_ops share a hash for a ftrace record, and the
first ops has a trampoline, when it adds itself it will set the rec-&gt;flags
TRAMP flag and increments its nr_trampolines counter. When the second ops
is added, it must clear that tramp flag but also decrement the other ops
that shares its hash. As the update to the function callbacks has not yet
been performed, the other ops will not have the tramp hash set yet and it
can not be used to know to decrement its nr_trampolines.

Luckily, the tramp_hash does not need to be used. As the ftrace_mutex is
held, a ops with a trampoline to a record during an update of another ops
that shares the record will have its func_hash pointing to it. Since a
trampoline can only be set for a record if only one ops is attached to it,
we can just check if the record has a trampoline (the FTRACE_FL_TRAMP flag
is set) and then find the ops that has this record in its hashes.

Also added some output to help debug when things go wrong.

Cc: stable@vger.kernel.org # 3.16+ (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Update all ftrace_ops for a ftrace_hash_ops update</title>
<updated>2014-08-22T17:21:14+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-08-18T17:21:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=84261912ebee41269004e8a9f3614ba38ef6b206'/>
<id>84261912ebee41269004e8a9f3614ba38ef6b206</id>
<content type='text'>
When updating what an ftrace_ops traces, if it is registered (that is,
actively tracing), and that ftrace_ops uses the shared global_ops
local_hash, then we need to update all tracers that are active and
also share the global_ops' ftrace_hash_ops.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When updating what an ftrace_ops traces, if it is registered (that is,
actively tracing), and that ftrace_ops uses the shared global_ops
local_hash, then we need to update all tracers that are active and
also share the global_ops' ftrace_hash_ops.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Allow ftrace_ops to use the hashes from other ops</title>
<updated>2014-08-22T17:18:48+00:00</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-08-15T21:23:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=33b7f99cf003ca6c1d31c42b50e1100ad71aaec0'/>
<id>33b7f99cf003ca6c1d31c42b50e1100ad71aaec0</id>
<content type='text'>
Currently the top level debug file system function tracer shares its
ftrace_ops with the function graph tracer. This was thought to be fine
because the tracers are not used together, as one can only enable
function or function_graph tracer in the current_tracer file.

But that assumption proved to be incorrect. The function profiler
can use the function graph tracer when function tracing is enabled.
Since all function graph users uses the function tracing ftrace_ops
this causes a conflict and when a user enables both function profiling
as well as the function tracer it will crash ftrace and disable it.

The quick solution so far is to move them as separate ftrace_ops like
it was earlier. The problem though is to synchronize the functions that
are traced because both function and function_graph tracer are limited
by the selections made in the set_ftrace_filter and set_ftrace_notrace
files.

To handle this, a new structure is made called ftrace_ops_hash. This
structure will now hold the filter_hash and notrace_hash, and the
ftrace_ops will point to this structure. That will allow two ftrace_ops
to share the same hashes.

Since most ftrace_ops do not share the hashes, and to keep allocation
simple, the ftrace_ops structure will include both a pointer to the
ftrace_ops_hash called func_hash, as well as the structure itself,
called local_hash. When the ops are registered, the func_hash pointer
will be initialized to point to the local_hash within the ftrace_ops
structure. Some of the ftrace internal ftrace_ops will be initialized
statically. This will allow for the function and function_graph tracer
to have separate ops but still share the same hash tables that determine
what functions they trace.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently the top level debug file system function tracer shares its
ftrace_ops with the function graph tracer. This was thought to be fine
because the tracers are not used together, as one can only enable
function or function_graph tracer in the current_tracer file.

But that assumption proved to be incorrect. The function profiler
can use the function graph tracer when function tracing is enabled.
Since all function graph users uses the function tracing ftrace_ops
this causes a conflict and when a user enables both function profiling
as well as the function tracer it will crash ftrace and disable it.

The quick solution so far is to move them as separate ftrace_ops like
it was earlier. The problem though is to synchronize the functions that
are traced because both function and function_graph tracer are limited
by the selections made in the set_ftrace_filter and set_ftrace_notrace
files.

To handle this, a new structure is made called ftrace_ops_hash. This
structure will now hold the filter_hash and notrace_hash, and the
ftrace_ops will point to this structure. That will allow two ftrace_ops
to share the same hashes.

Since most ftrace_ops do not share the hashes, and to keep allocation
simple, the ftrace_ops structure will include both a pointer to the
ftrace_ops_hash called func_hash, as well as the structure itself,
called local_hash. When the ops are registered, the func_hash pointer
will be initialized to point to the local_hash within the ftrace_ops
structure. Some of the ftrace internal ftrace_ops will be initialized
statically. This will allow for the function and function_graph tracer
to have separate ops but still share the same hash tables that determine
what functions they trace.

Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Handle compat ioctl</title>
<updated>2014-08-20T07:42:13+00:00</updated>
<author>
<name>Pawel Moll</name>
<email>pawel.moll@arm.com</email>
</author>
<published>2014-06-13T15:03:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b3f207855f57b9c8f43a547a801340bb5cbc59e5'/>
<id>b3f207855f57b9c8f43a547a801340bb5cbc59e5</id>
<content type='text'>
When running a 32-bit userspace on a 64-bit kernel (eg. i386
application on x86_64 kernel or 32-bit arm userspace on arm64
kernel) some of the perf ioctls must be treated with special
care, as they have a pointer size encoded in the command.

For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded
as 0x80042407, but 64-bit kernel will expect 0x80082407. In
result the ioctl will fail returning -ENOTTY.

This patch solves the problem by adding code fixing up the
size as compat_ioctl file operation.

Reported-by: Drew Richardson &lt;drew.richardson@arm.com&gt;
Signed-off-by: Pawel Moll &lt;pawel.moll@arm.com&gt;
Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When running a 32-bit userspace on a 64-bit kernel (eg. i386
application on x86_64 kernel or 32-bit arm userspace on arm64
kernel) some of the perf ioctls must be treated with special
care, as they have a pointer size encoded in the command.

For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded
as 0x80042407, but 64-bit kernel will expect 0x80082407. In
result the ioctl will fail returning -ENOTTY.

This patch solves the problem by adding code fixing up the
size as compat_ioctl file operation.

Reported-by: Drew Richardson &lt;drew.richardson@arm.com&gt;
Signed-off-by: Pawel Moll &lt;pawel.moll@arm.com&gt;
Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>module: Clean up ro/nx after early module load failures</title>
<updated>2014-08-15T19:17:00+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2014-08-15T18:43:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ff7e0055bb5ddbbb320cdd8dfd3e18672bddd2ad'/>
<id>ff7e0055bb5ddbbb320cdd8dfd3e18672bddd2ad</id>
<content type='text'>
The commit

    4982223e51e8 module: set nx before marking module MODULE_STATE_COMING.

introduced a regression: if a module fails to parse its arguments or
if mod_sysfs_setup fails, then the module's memory will be freed
while still read-only.  Anything that reuses that memory will crash
as soon as it tries to write to it.

Cc: stable@vger.kernel.org # v3.16
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The commit

    4982223e51e8 module: set nx before marking module MODULE_STATE_COMING.

introduced a regression: if a module fails to parse its arguments or
if mod_sysfs_setup fails, then the module's memory will be freed
while still read-only.  Anything that reuses that memory will crash
as soon as it tries to write to it.

Cc: stable@vger.kernel.org # v3.16
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2014-08-15T00:13:46+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-08-15T00:13:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c9d26423e56ce1ab4d786f92aebecf859d419293'/>
<id>c9d26423e56ce1ab4d786f92aebecf859d419293</id>
<content type='text'>
Pull more ACPI and power management updates from Rafael Wysocki:
 "These are a couple of regression fixes, cpuidle menu governor
  optimizations, fixes for ACPI proccessor and battery drivers,
  hibernation fix to avoid problems related to the e820 memory map,
  fixes for a few cpufreq drivers and a new version of the suspend
  profiling tool analyze_suspend.py.

  Specifics:

   - Fix for an ACPI-based device hotplug regression introduced in 3.14
     that causes a kernel panic to trigger when memory hot-remove is
     attempted with CONFIG_ACPI_HOTPLUG_MEMORY unset from Tang Chen

   - Fix for a cpufreq regression introduced in 3.16 that triggers a
     "sleeping function called from invalid context" bug in
     dev_pm_opp_init_cpufreq_table() from Stephen Boyd

   - ACPI battery driver fix for a warning message added in 3.16 that
     prints silly stuff sometimes from Mariusz Ceier

   - Hibernation fix for safer handling of mismatches in the 820 memory
     map between the configurations during image creation and during the
     subsequent restore from Chun-Yi Lee

   - ACPI processor driver fix to handle CPU hotplug notifications
     correctly during system suspend/resume from Lan Tianyu

   - Series of four cpuidle menu governor cleanups that also should
     speed it up a bit from Mel Gorman

   - Fixes for the speedstep-smi, integrator, cpu0 and arm_big_little
     cpufreq drivers from Hans Wennborg, Himangi Saraogi, Markus
     Pargmann and Uwe Kleine-König

   - Version 3.0 of the analyze_suspend.py suspend profiling tool from
     Todd E Brandt"

* tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / battery: Fix warning message in acpi_battery_get_state()
  PM / tools: analyze_suspend.py: update to v3.0
  cpufreq: arm_big_little: fix module license spec
  cpufreq: speedstep-smi: fix decimal printf specifiers
  ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove()
  cpufreq: OPP: Avoid sleeping while atomic
  cpufreq: cpu0: Do not print error message when deferring
  cpufreq: integrator: Use set_cpus_allowed_ptr
  PM / hibernate: avoid unsafe pages in e820 reserved regions
  ACPI / processor: Make acpi_cpu_soft_notify() process CPU FROZEN events
  cpuidle: menu: Lookup CPU runqueues less
  cpuidle: menu: Call nr_iowait_cpu less times
  cpuidle: menu: Use ktime_to_us instead of reinventing the wheel
  cpuidle: menu: Use shifts when calculating averages where possible
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more ACPI and power management updates from Rafael Wysocki:
 "These are a couple of regression fixes, cpuidle menu governor
  optimizations, fixes for ACPI proccessor and battery drivers,
  hibernation fix to avoid problems related to the e820 memory map,
  fixes for a few cpufreq drivers and a new version of the suspend
  profiling tool analyze_suspend.py.

  Specifics:

   - Fix for an ACPI-based device hotplug regression introduced in 3.14
     that causes a kernel panic to trigger when memory hot-remove is
     attempted with CONFIG_ACPI_HOTPLUG_MEMORY unset from Tang Chen

   - Fix for a cpufreq regression introduced in 3.16 that triggers a
     "sleeping function called from invalid context" bug in
     dev_pm_opp_init_cpufreq_table() from Stephen Boyd

   - ACPI battery driver fix for a warning message added in 3.16 that
     prints silly stuff sometimes from Mariusz Ceier

   - Hibernation fix for safer handling of mismatches in the 820 memory
     map between the configurations during image creation and during the
     subsequent restore from Chun-Yi Lee

   - ACPI processor driver fix to handle CPU hotplug notifications
     correctly during system suspend/resume from Lan Tianyu

   - Series of four cpuidle menu governor cleanups that also should
     speed it up a bit from Mel Gorman

   - Fixes for the speedstep-smi, integrator, cpu0 and arm_big_little
     cpufreq drivers from Hans Wennborg, Himangi Saraogi, Markus
     Pargmann and Uwe Kleine-König

   - Version 3.0 of the analyze_suspend.py suspend profiling tool from
     Todd E Brandt"

* tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / battery: Fix warning message in acpi_battery_get_state()
  PM / tools: analyze_suspend.py: update to v3.0
  cpufreq: arm_big_little: fix module license spec
  cpufreq: speedstep-smi: fix decimal printf specifiers
  ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove()
  cpufreq: OPP: Avoid sleeping while atomic
  cpufreq: cpu0: Do not print error message when deferring
  cpufreq: integrator: Use set_cpus_allowed_ptr
  PM / hibernate: avoid unsafe pages in e820 reserved regions
  ACPI / processor: Make acpi_cpu_soft_notify() process CPU FROZEN events
  cpuidle: menu: Lookup CPU runqueues less
  cpuidle: menu: Call nr_iowait_cpu less times
  cpuidle: menu: Use ktime_to_us instead of reinventing the wheel
  cpuidle: menu: Use shifts when calculating averages where possible
</pre>
</div>
</content>
</entry>
</feed>
