2010-07-20 03:13:35 -04:00
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2008-05-12 21:20:42 +02:00
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2009-03-05 01:49:22 +01:00
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2008-10-02 13:26:05 +02:00
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2009-03-05 01:49:22 +01:00
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2008-12-03 15:36:57 -05:00
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2011-08-09 12:50:46 -04:00
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2009-03-05 01:49:22 +01:00
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2008-12-04 23:51:23 +01:00
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2009-03-05 01:49:22 +01:00
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2008-05-12 21:20:42 +02:00
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2009-02-27 21:30:03 +01:00
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2011-08-08 16:57:47 -04:00
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2012-06-05 09:44:25 -04:00
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2011-05-26 13:46:22 -04:00
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2011-07-11 10:12:59 -04:00
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2008-10-06 19:06:12 -04:00
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2008-10-02 17:45:47 +02:00
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2008-05-12 21:20:43 +02:00
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2009-09-23 15:57:19 -07:00
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2008-05-12 21:20:43 +02:00
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2011-08-08 16:57:47 -04:00
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2011-08-09 12:50:46 -04:00
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2008-05-12 21:20:42 +02:00
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2012-02-15 15:51:48 +01:00
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2012-04-30 16:20:23 -04:00
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2012-07-20 11:04:44 -04:00
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2012-02-15 15:51:48 +01:00
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2011-05-04 09:27:52 -04:00
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2012-04-30 16:20:23 -04:00
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2012-07-20 11:04:44 -04:00
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2011-05-04 09:27:52 -04:00
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2008-05-12 21:20:42 +02:00
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2011-05-02 12:29:25 -04:00
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2011-05-04 09:27:52 -04:00
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2012-02-15 15:51:48 +01:00
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2011-05-02 12:29:25 -04:00
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2008-05-12 21:20:42 +02:00
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2008-11-05 16:05:44 -05:00
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2008-11-16 06:02:06 +01:00
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2008-11-05 16:05:44 -05:00
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2008-05-12 21:20:42 +02:00
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2012-02-15 15:51:48 +01:00
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2011-08-09 12:50:46 -04:00
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2008-05-12 21:20:42 +02:00
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2008-10-06 19:06:12 -04:00
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2010-05-04 11:24:01 -04:00
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2012-07-20 13:08:05 -04:00
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2010-05-04 11:24:01 -04:00
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2008-10-23 09:33:02 -04:00
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2008-11-05 16:05:44 -05:00
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2008-10-06 19:06:12 -04:00
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2008-05-12 21:20:42 +02:00
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2008-12-16 23:06:40 -05:00
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2009-09-23 15:57:19 -07:00
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2008-12-16 23:06:40 -05:00
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2009-02-14 00:40:25 -05:00
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2011-07-07 11:09:22 -04:00
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2009-02-14 00:40:25 -05:00
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ftrace: dynamic enabling/disabling of function calls
This patch adds a feature to dynamically replace the ftrace code
with the jmps to allow a kernel with ftrace configured to run
as fast as it can without it configured.
The way this works, is on bootup (if ftrace is enabled), a ftrace
function is registered to record the instruction pointer of all
places that call the function.
Later, if there's still any code to patch, a kthread is awoken
(rate limited to at most once a second) that performs a stop_machine,
and replaces all the code that was called with a jmp over the call
to ftrace. It only replaces what was found the previous time. Typically
the system reaches equilibrium quickly after bootup and there's no code
patching needed at all.
e.g.
call ftrace /* 5 bytes */
is replaced with
jmp 3f /* jmp is 2 bytes and we jump 3 forward */
3:
When we want to enable ftrace for function tracing, the IP recording
is removed, and stop_machine is called again to replace all the locations
of that were recorded back to the call of ftrace. When it is disabled,
we replace the code back to the jmp.
Allocation is done by the kthread. If the ftrace recording function is
called, and we don't have any record slots available, then we simply
skip that call. Once a second a new page (if needed) is allocated for
recording new ftrace function calls. A large batch is allocated at
boot up to get most of the calls there.
Because we do this via stop_machine, we don't have to worry about another
CPU executing a ftrace call as we modify it. But we do need to worry
about NMI's so all functions that might be called via nmi must be
annotated with notrace_nmi. When this code is configured in, the NMI code
will not call notrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 21:20:42 +02:00
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2008-11-14 16:21:19 -08:00
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2009-02-17 13:35:06 -05:00
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2011-08-16 09:53:39 -04:00
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2009-02-16 23:06:01 -05:00
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2009-02-17 12:32:04 -05:00
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ftrace: trace different functions with a different tracer
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-14 15:29:06 -05:00
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2009-02-16 23:06:01 -05:00
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2009-02-17 12:32:04 -05:00
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2009-02-16 23:06:01 -05:00
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|
ftrace: trace different functions with a different tracer
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-14 15:29:06 -05:00
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|
|
2009-02-17 12:32:04 -05:00
|
|
|
|
ftrace: trace different functions with a different tracer
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-14 15:29:06 -05:00
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|
|
|
|
|
|
|
|
2009-02-17 12:32:04 -05:00
|
|
|
|
ftrace: trace different functions with a different tracer
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-14 15:29:06 -05:00
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2009-02-17 12:32:04 -05:00
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ftrace: trace different functions with a different tracer
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-14 15:29:06 -05:00
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2010-02-02 16:49:11 -05:00
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2012-07-20 13:08:05 -04:00
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2012-04-30 16:20:23 -04:00
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2008-05-12 21:20:43 +02:00
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2012-04-30 16:20:23 -04:00
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2008-05-12 21:20:43 +02:00
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2012-04-30 16:20:23 -04:00
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2011-05-03 13:25:24 -04:00
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ftrace: dynamic enabling/disabling of function calls
This patch adds a feature to dynamically replace the ftrace code
with the jmps to allow a kernel with ftrace configured to run
as fast as it can without it configured.
The way this works, is on bootup (if ftrace is enabled), a ftrace
function is registered to record the instruction pointer of all
places that call the function.
Later, if there's still any code to patch, a kthread is awoken
(rate limited to at most once a second) that performs a stop_machine,
and replaces all the code that was called with a jmp over the call
to ftrace. It only replaces what was found the previous time. Typically
the system reaches equilibrium quickly after bootup and there's no code
patching needed at all.
e.g.
call ftrace /* 5 bytes */
is replaced with
jmp 3f /* jmp is 2 bytes and we jump 3 forward */
3:
When we want to enable ftrace for function tracing, the IP recording
is removed, and stop_machine is called again to replace all the locations
of that were recorded back to the call of ftrace. When it is disabled,
we replace the code back to the jmp.
Allocation is done by the kthread. If the ftrace recording function is
called, and we don't have any record slots available, then we simply
skip that call. Once a second a new page (if needed) is allocated for
recording new ftrace function calls. A large batch is allocated at
boot up to get most of the calls there.
Because we do this via stop_machine, we don't have to worry about another
CPU executing a ftrace call as we modify it. But we do need to worry
about NMI's so all functions that might be called via nmi must be
annotated with notrace_nmi. When this code is configured in, the NMI code
will not call notrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 21:20:42 +02:00
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2009-03-24 13:38:06 +08:00
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2011-12-16 16:30:31 -05:00
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2009-03-24 13:38:06 +08:00
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ftrace: dynamic enabling/disabling of function calls
This patch adds a feature to dynamically replace the ftrace code
with the jmps to allow a kernel with ftrace configured to run
as fast as it can without it configured.
The way this works, is on bootup (if ftrace is enabled), a ftrace
function is registered to record the instruction pointer of all
places that call the function.
Later, if there's still any code to patch, a kthread is awoken
(rate limited to at most once a second) that performs a stop_machine,
and replaces all the code that was called with a jmp over the call
to ftrace. It only replaces what was found the previous time. Typically
the system reaches equilibrium quickly after bootup and there's no code
patching needed at all.
e.g.
call ftrace /* 5 bytes */
is replaced with
jmp 3f /* jmp is 2 bytes and we jump 3 forward */
3:
When we want to enable ftrace for function tracing, the IP recording
is removed, and stop_machine is called again to replace all the locations
of that were recorded back to the call of ftrace. When it is disabled,
we replace the code back to the jmp.
Allocation is done by the kthread. If the ftrace recording function is
called, and we don't have any record slots available, then we simply
skip that call. Once a second a new page (if needed) is allocated for
recording new ftrace function calls. A large batch is allocated at
boot up to get most of the calls there.
Because we do this via stop_machine, we don't have to worry about another
CPU executing a ftrace call as we modify it. But we do need to worry
about NMI's so all functions that might be called via nmi must be
annotated with notrace_nmi. When this code is configured in, the NMI code
will not call notrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 21:20:42 +02:00
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2008-05-12 21:20:44 +02:00
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2012-06-05 19:28:08 +09:00
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2012-01-02 10:04:14 +01:00
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2011-05-05 22:54:01 -04:00
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2012-01-02 10:04:14 +01:00
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2011-05-05 22:54:01 -04:00
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ftrace, perf: Add filter support for function trace event
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.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-15 15:51:54 +01:00
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2008-05-12 21:20:44 +02:00
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2009-02-14 00:40:25 -05:00
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2011-08-16 09:53:39 -04:00
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2012-04-30 16:20:23 -04:00
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2011-08-16 09:53:39 -04:00
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2012-04-30 16:20:23 -04:00
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2011-08-16 09:53:39 -04:00
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2011-12-19 14:41:25 -05:00
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2011-12-19 15:21:16 -05:00
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2011-12-19 14:41:25 -05:00
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2011-08-16 09:53:39 -04:00
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2011-08-16 09:57:10 -04:00
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2011-08-16 09:53:39 -04:00
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2012-04-25 14:39:54 -04:00
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2011-08-16 09:53:39 -04:00
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2011-12-19 14:41:25 -05:00
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2011-12-19 21:57:44 -05:00
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ftrace: dynamic enabling/disabling of function calls
This patch adds a feature to dynamically replace the ftrace code
with the jmps to allow a kernel with ftrace configured to run
as fast as it can without it configured.
The way this works, is on bootup (if ftrace is enabled), a ftrace
function is registered to record the instruction pointer of all
places that call the function.
Later, if there's still any code to patch, a kthread is awoken
(rate limited to at most once a second) that performs a stop_machine,
and replaces all the code that was called with a jmp over the call
to ftrace. It only replaces what was found the previous time. Typically
the system reaches equilibrium quickly after bootup and there's no code
patching needed at all.
e.g.
call ftrace /* 5 bytes */
is replaced with
jmp 3f /* jmp is 2 bytes and we jump 3 forward */
3:
When we want to enable ftrace for function tracing, the IP recording
is removed, and stop_machine is called again to replace all the locations
of that were recorded back to the call of ftrace. When it is disabled,
we replace the code back to the jmp.
Allocation is done by the kthread. If the ftrace recording function is
called, and we don't have any record slots available, then we simply
skip that call. Once a second a new page (if needed) is allocated for
recording new ftrace function calls. A large batch is allocated at
boot up to get most of the calls there.
Because we do this via stop_machine, we don't have to worry about another
CPU executing a ftrace call as we modify it. But we do need to worry
about NMI's so all functions that might be called via nmi must be
annotated with notrace_nmi. When this code is configured in, the NMI code
will not call notrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-12 21:20:42 +02:00
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2008-05-12 21:20:43 +02:00
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2008-05-12 21:20:43 +02:00
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2012-04-27 09:13:18 -04:00
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2008-05-12 21:20:43 +02:00
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2012-04-30 16:20:23 -04:00
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2008-05-12 21:20:43 +02:00
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2012-04-30 16:20:23 -04:00
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2008-05-12 21:20:43 +02:00
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2009-01-09 11:29:42 +08:00
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2012-04-26 14:59:43 -04:00
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2009-01-09 11:29:42 +08:00
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2012-04-30 16:20:23 -04:00
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2008-11-25 21:07:04 +01:00
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2008-11-26 00:16:24 -05:00
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2008-11-16 06:02:06 +01:00
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ftrace: user update and disable dynamic ftrace daemon
In dynamic ftrace, the mcount function starts off pointing to a stub
function that just returns.
On start up, the call to the stub is modified to point to a "record_ip"
function. The job of the record_ip function is to add the function to
a pre-allocated hash list. If the function is already there, it simply is
ignored, otherwise it is added to the list.
Later, a ftraced daemon wakes up and calls kstop_machine if any functions
have been recorded, and changes the calls to the recorded functions to
a simple nop. If no functions were recorded, the daemon goes back to sleep.
The daemon wakes up once a second to see if it needs to update any newly
recorded functions into nops. Usually it does not, but if a lot of code
has been executed for the first time in the kernel, the ftraced daemon
will call kstop_machine to update those into nops.
The problem currently is that there's no way to stop the daemon from doing
this, and it can cause unneeded latencies (800us which for some is bothersome).
This patch adds a new file /debugfs/tracing/ftraced_enabled. If the daemon
is active, reading this will return "enabled\n" and "disabled\n" when the
daemon is not running. To disable the daemon, the user can echo "0" or
"disable" into this file, and "1" or "enable" to re-enable the daemon.
Since the daemon is used to convert the functions into nops to increase
the performance of the system, I also added that anytime something is
written into the ftraced_enabled file, kstop_machine will run if there
are new functions that have been detected that need to be converted.
This way the user can disable the daemon but still be able to control the
conversion of the mcount calls to nops by simply,
"echo 0 > /debugfs/tracing/ftraced_enabled"
when they need to do more conversions.
To see the number of converted functions:
"cat /debugfs/tracing/dyn_ftrace_total_info"
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-27 20:48:37 -04:00
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2008-10-23 09:32:59 -04:00
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2009-02-06 17:33:27 +08:00
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2008-11-14 16:21:19 -08:00
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2008-10-23 09:32:59 -04:00
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2008-11-14 16:21:19 -08:00
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2008-10-23 09:32:59 -04:00
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2008-11-14 16:21:19 -08:00
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2012-04-30 16:20:23 -04:00
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2008-11-14 16:21:19 -08:00
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2008-10-23 09:32:59 -04:00
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2008-06-21 23:47:53 +05:30
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2008-09-06 01:06:03 -04:00
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2008-05-12 21:20:44 +02:00
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2010-05-04 11:24:01 -04:00
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2009-10-07 19:00:35 +02:00
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2009-02-14 00:40:25 -05:00
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2009-02-17 11:47:39 +01:00
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2009-02-14 00:40:25 -05:00
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2009-02-17 11:47:39 +01:00
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2009-02-14 00:40:25 -05:00
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2010-02-02 16:49:11 -05:00
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2011-12-19 14:41:25 -05:00
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2012-01-07 17:26:49 -05:00
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2012-06-05 19:28:08 +09:00
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ftrace, perf: Add filter support for function trace event
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.com
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-15 15:51:54 +01:00
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2011-12-19 14:41:25 -05:00
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2008-06-21 23:47:53 +05:30
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2008-05-12 21:20:42 +02:00
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2008-05-12 21:20:49 +02:00
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2008-05-12 21:20:43 +02:00
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2008-10-06 19:06:12 -04:00
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2008-05-12 21:20:43 +02:00
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2008-08-18 16:24:56 +08:00
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2008-08-15 00:40:25 -07:00
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2008-08-18 16:24:56 +08:00
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2008-08-15 00:40:25 -07:00
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2008-10-06 19:06:12 -04:00
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2008-08-15 00:40:25 -07:00
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2008-10-06 19:06:12 -04:00
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2008-08-15 00:40:25 -07:00
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2009-02-27 21:30:03 +01:00
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2008-05-12 21:20:42 +02:00
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2008-05-12 21:20:42 +02:00
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2008-02-25 13:38:05 +01:00
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2008-05-12 21:20:42 +02:00
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2010-05-04 11:24:01 -04:00
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2008-05-12 21:20:42 +02:00
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2008-05-12 21:20:42 +02:00
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2008-02-25 13:38:05 +01:00
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2008-05-12 21:20:42 +02:00
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2012-05-07 11:36:00 +09:00
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2008-05-12 21:20:42 +02:00
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2008-08-14 15:45:08 -04:00
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2008-11-26 00:57:25 +01:00
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2008-08-01 12:26:41 -04:00
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2008-11-11 07:03:45 +01:00
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2008-11-25 21:07:04 +01:00
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2008-11-11 07:03:45 +01:00
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2008-11-17 03:22:41 +01:00
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2008-11-26 00:57:25 +01:00
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2008-11-11 07:03:45 +01:00
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2010-04-02 19:01:22 +02:00
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2008-11-25 21:07:04 +01:00
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2008-12-06 03:40:00 +01:00
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2009-03-25 20:55:00 -04:00
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2009-04-08 14:05:43 +09:00
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2009-03-25 20:55:00 -04:00
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2009-02-09 10:54:03 -08:00
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2009-03-24 23:17:58 -04:00
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function-graph: add stack frame test
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.
An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.
This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.
There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.
This test detected the problem and pointed out where the issue was.
This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.
Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-18 12:45:08 -04:00
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2009-02-09 10:54:03 -08:00
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function-graph: add stack frame test
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.
An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.
This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.
There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.
This test detected the problem and pointed out where the issue was.
This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.
Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-18 12:45:08 -04:00
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2009-02-09 10:54:03 -08:00
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2008-12-06 03:40:00 +01:00
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2008-12-09 23:54:20 +01:00
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2008-11-23 06:22:56 +01:00
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2008-11-26 00:57:25 +01:00
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2008-11-23 06:22:56 +01:00
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2008-12-02 23:50:02 -05:00
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2008-11-26 00:57:25 +01:00
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2008-11-11 07:03:45 +01:00
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2008-11-25 21:07:04 +01:00
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2008-11-23 06:22:56 +01:00
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2008-11-25 21:07:04 +01:00
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ftrace: Fix memory leak with function graph and cpu hotplug
When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.
On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.
ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.
The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-10 21:26:13 -05:00
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2008-12-04 23:51:23 +01:00
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2008-12-06 03:43:41 +01:00
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2009-03-25 20:55:00 -04:00
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2008-12-06 03:40:00 +01:00
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2008-12-09 23:54:20 +01:00
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2009-03-25 20:55:00 -04:00
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2008-12-06 03:40:00 +01:00
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2008-11-25 21:07:04 +01:00
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|
ftrace: Fix memory leak with function graph and cpu hotplug
When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.
On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.
ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.
The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-10 21:26:13 -05:00
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2008-12-04 23:51:23 +01:00
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2010-04-02 19:01:22 +02:00
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2008-12-04 23:51:23 +01:00
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2008-12-06 03:43:41 +01:00
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2009-03-25 20:55:00 -04:00
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2008-11-11 07:03:45 +01:00
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2008-12-03 15:36:57 -05:00
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2010-04-18 19:08:41 +02:00
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2009-03-05 10:28:45 +01:00
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tracing: add same level recursion detection
The tracing infrastructure allows for recursion. That is, an interrupt
may interrupt the act of tracing an event, and that interrupt may very well
perform its own trace. This is a recursive trace, and is fine to do.
The problem arises when there is a bug, and the utility doing the trace
calls something that recurses back into the tracer. This recursion is not
caused by an external event like an interrupt, but by code that is not
expected to recurse. The result could be a lockup.
This patch adds a bitmask to the task structure that keeps track
of the trace recursion. To find the interrupt depth, the following
algorithm is used:
level = hardirq_count() + softirq_count() + in_nmi;
Here, level will be the depth of interrutps and softirqs, and even handles
the nmi. Then the corresponding bit is set in the recursion bitmask.
If the bit was already set, we know we had a recursion at the same level
and we warn about it and fail the writing to the buffer.
After the data has been committed to the buffer, we clear the bit.
No atomics are needed. The only races are with interrupts and they reset
the bitmask before returning anywy.
[ Impact: detect same irq level trace recursion ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-16 21:41:52 -04:00
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2008-12-03 15:36:57 -05:00
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tracing: add same level recursion detection
The tracing infrastructure allows for recursion. That is, an interrupt
may interrupt the act of tracing an event, and that interrupt may very well
perform its own trace. This is a recursive trace, and is fine to do.
The problem arises when there is a bug, and the utility doing the trace
calls something that recurses back into the tracer. This recursion is not
caused by an external event like an interrupt, but by code that is not
expected to recurse. The result could be a lockup.
This patch adds a bitmask to the task structure that keeps track
of the trace recursion. To find the interrupt depth, the following
algorithm is used:
level = hardirq_count() + softirq_count() + in_nmi;
Here, level will be the depth of interrutps and softirqs, and even handles
the nmi. Then the corresponding bit is set in the recursion bitmask.
If the bit was already set, we know we had a recursion at the same level
and we warn about it and fail the writing to the buffer.
After the data has been committed to the buffer, we clear the bit.
No atomics are needed. The only races are with interrupts and they reset
the bitmask before returning anywy.
[ Impact: detect same irq level trace recursion ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-16 21:41:52 -04:00
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2009-01-19 10:31:01 +01:00
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2010-01-26 04:40:03 -05:00
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2008-05-12 21:20:42 +02:00
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