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Commit fc13cb0c authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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ftrace: Allow other users of function tracing to use the output listing 



The function tracer is set up to allow any other subsystem (like perf)
to use it. Ftrace already has a way to list what functions are enabled
by the global_ops. It would be very helpful to let other users of
the function tracer to be able to use the same code.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 06a51d93

include/linux/ftrace.h

+35 −0
Original line number Diff line number Diff line
@@ -202,6 +202,14 @@ enum { 
	FTRACE_UPDATE_MAKE_NOP,

};



enum {

	FTRACE_ITER_FILTER	= (1 << 0),

	FTRACE_ITER_NOTRACE	= (1 << 1),

	FTRACE_ITER_PRINTALL	= (1 << 2),

	FTRACE_ITER_HASH	= (1 << 3),

	FTRACE_ITER_ENABLED	= (1 << 4),

};



void arch_ftrace_update_code(int command);



struct ftrace_rec_iter;
@@ -217,6 +225,15 @@ int ftrace_location(unsigned long ip); 


extern ftrace_func_t ftrace_trace_function;



int ftrace_regex_open(struct ftrace_ops *ops, int flag,

		  struct inode *inode, struct file *file);

ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,

			    size_t cnt, loff_t *ppos);

ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,

			     size_t cnt, loff_t *ppos);

loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);

int ftrace_regex_release(struct inode *inode, struct file *file);



/* defined in arch */

extern int ftrace_ip_converted(unsigned long ip);

extern int ftrace_dyn_arch_init(void *data);
@@ -311,6 +328,24 @@ static inline int ftrace_text_reserved(void *start, void *end) 
{

	return 0;

}



/*

 * Again users of functions that have ftrace_ops may not

 * have them defined when ftrace is not enabled, but these

 * functions may still be called. Use a macro instead of inline.

 */

#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })



static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,

			    size_t cnt, loff_t *ppos) { return -ENODEV; }

static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,

			     size_t cnt, loff_t *ppos) { return -ENODEV; }

static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin)

{

	return -ENODEV;

}

static inline int

ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }

#endif /* CONFIG_DYNAMIC_FTRACE */



/* totally disable ftrace - can not re-enable after this */

kernel/trace/ftrace.c

+25 −16
Original line number Diff line number Diff line
@@ -2134,14 +2134,6 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) 
	return 0;

}



enum {

	FTRACE_ITER_FILTER	= (1 << 0),

	FTRACE_ITER_NOTRACE	= (1 << 1),

	FTRACE_ITER_PRINTALL	= (1 << 2),

	FTRACE_ITER_HASH	= (1 << 3),

	FTRACE_ITER_ENABLED	= (1 << 4),

};



#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */



struct ftrace_iterator {
@@ -2249,7 +2241,7 @@ static void * 
t_next(struct seq_file *m, void *v, loff_t *pos)

{

	struct ftrace_iterator *iter = m->private;

	struct ftrace_ops *ops = &global_ops;

	struct ftrace_ops *ops = iter->ops;

	struct dyn_ftrace *rec = NULL;



	if (unlikely(ftrace_disabled))
@@ -2305,7 +2297,7 @@ static void reset_iter_read(struct ftrace_iterator *iter) 
static void *t_start(struct seq_file *m, loff_t *pos)

{

	struct ftrace_iterator *iter = m->private;

	struct ftrace_ops *ops = &global_ops;

	struct ftrace_ops *ops = iter->ops;

	void *p = NULL;

	loff_t l;
@@ -2414,6 +2406,7 @@ ftrace_avail_open(struct inode *inode, struct file *file) 
		return -ENOMEM;



	iter->pg = ftrace_pages_start;

	iter->ops = &global_ops;



	ret = seq_open(file, &show_ftrace_seq_ops);

	if (!ret) {
@@ -2442,6 +2435,7 @@ ftrace_enabled_open(struct inode *inode, struct file *file) 


	iter->pg = ftrace_pages_start;

	iter->flags = FTRACE_ITER_ENABLED;

	iter->ops = &global_ops;



	ret = seq_open(file, &show_ftrace_seq_ops);

	if (!ret) {
@@ -2462,7 +2456,23 @@ static void ftrace_filter_reset(struct ftrace_hash *hash) 
	mutex_unlock(&ftrace_lock);

}



static int

/**

 * ftrace_regex_open - initialize function tracer filter files

 * @ops: The ftrace_ops that hold the hash filters

 * @flag: The type of filter to process

 * @inode: The inode, usually passed in to your open routine

 * @file: The file, usually passed in to your open routine

 *

 * ftrace_regex_open() initializes the filter files for the

 * @ops. Depending on @flag it may process the filter hash or

 * the notrace hash of @ops. With this called from the open

 * routine, you can use ftrace_filter_write() for the write

 * routine if @flag has FTRACE_ITER_FILTER set, or

 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.

 * ftrace_regex_lseek() should be used as the lseek routine, and

 * release must call ftrace_regex_release().

 */

int

ftrace_regex_open(struct ftrace_ops *ops, int flag,

		  struct inode *inode, struct file *file)

{
@@ -2542,7 +2552,7 @@ ftrace_notrace_open(struct inode *inode, struct file *file) 
				 inode, file);

}



static loff_t

loff_t

ftrace_regex_lseek(struct file *file, loff_t offset, int origin)

{

	loff_t ret;
@@ -3095,14 +3105,14 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, 
	return ret;

}



static ssize_t

ssize_t

ftrace_filter_write(struct file *file, const char __user *ubuf,

		    size_t cnt, loff_t *ppos)

{

	return ftrace_regex_write(file, ubuf, cnt, ppos, 1);

}



static ssize_t

ssize_t

ftrace_notrace_write(struct file *file, const char __user *ubuf,

		     size_t cnt, loff_t *ppos)

{
@@ -3292,8 +3302,7 @@ static void __init set_ftrace_early_filters(void) 
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

}



static int

ftrace_regex_release(struct inode *inode, struct file *file)

int ftrace_regex_release(struct inode *inode, struct file *file)

{

	struct seq_file *m = (struct seq_file *)file->private_data;

	struct ftrace_iterator *iter;