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Commit 45a4a237 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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ftrace: Remove FTRACE_FL_FAILED flag 



Since we disable all function tracer processing if we detect
that a modification of a instruction had failed, we do not need
to track that the record has failed. No more ftrace processing
is allowed, and the FTRACE_FL_FAILED flag is pointless.

Removing this flag simplifies some of the code, but some ftrace_disabled
checks needed to be added or move around a little.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 3499e461

include/linux/ftrace.h

+4 −5
Original line number Diff line number Diff line
@@ -147,11 +147,10 @@ extern int ftrace_text_reserved(void *start, void *end); 


enum {

	FTRACE_FL_FREE		= (1 << 0),

	FTRACE_FL_FAILED	= (1 << 1),

	FTRACE_FL_FILTER	= (1 << 2),

	FTRACE_FL_ENABLED	= (1 << 3),

	FTRACE_FL_NOTRACE	= (1 << 4),

	FTRACE_FL_CONVERTED	= (1 << 5),

	FTRACE_FL_FILTER	= (1 << 1),

	FTRACE_FL_ENABLED	= (1 << 2),

	FTRACE_FL_NOTRACE	= (1 << 3),

	FTRACE_FL_CONVERTED	= (1 << 4),

};



struct dyn_ftrace {

kernel/trace/ftrace.c

+47 −29
Original line number Diff line number Diff line
@@ -1083,19 +1083,20 @@ static void ftrace_replace_code(int enable) 
	struct ftrace_page *pg;

	int failed;



	if (unlikely(ftrace_disabled))

		return;



	do_for_each_ftrace_rec(pg, rec) {

		/*

		 * Skip over free records, records that have

		 * failed and not converted.

		 */

		if (rec->flags & FTRACE_FL_FREE ||

		    rec->flags & FTRACE_FL_FAILED ||

		    !(rec->flags & FTRACE_FL_CONVERTED))

			continue;



		failed = __ftrace_replace_code(rec, enable);

		if (failed) {

			rec->flags |= FTRACE_FL_FAILED;

			ftrace_bug(failed, rec->ip);

			/* Stop processing */

			return;
@@ -1111,10 +1112,12 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) 


	ip = rec->ip;



	if (unlikely(ftrace_disabled))

		return 0;



	ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);

	if (ret) {

		ftrace_bug(ret, ip);

		rec->flags |= FTRACE_FL_FAILED;

		return 0;

	}

	return 1;
@@ -1466,6 +1469,9 @@ t_next(struct seq_file *m, void *v, loff_t *pos) 
	struct ftrace_iterator *iter = m->private;

	struct dyn_ftrace *rec = NULL;



	if (unlikely(ftrace_disabled))

		return NULL;



	if (iter->flags & FTRACE_ITER_HASH)

		return t_hash_next(m, pos);
@@ -1518,6 +1524,10 @@ static void *t_start(struct seq_file *m, loff_t *pos) 
	loff_t l;



	mutex_lock(&ftrace_lock);



	if (unlikely(ftrace_disabled))

		return NULL;



	/*

	 * If an lseek was done, then reset and start from beginning.

	 */
@@ -1636,8 +1646,6 @@ static void ftrace_filter_reset(int enable) 
	if (enable)

		ftrace_filtered = 0;

	do_for_each_ftrace_rec(pg, rec) {

		if (rec->flags & FTRACE_FL_FAILED)

			continue;

		rec->flags &= ~type;

	} while_for_each_ftrace_rec();

	mutex_unlock(&ftrace_lock);
@@ -1767,9 +1775,6 @@ static int ftrace_match_records(char *buff, int len, int enable) 
	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)

			continue;



		if (ftrace_match_record(rec, search, search_len, type)) {

			if (not)

				rec->flags &= ~flag;
@@ -1837,10 +1842,11 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) 
	}



	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)

			continue;

	if (unlikely(ftrace_disabled))

		goto out_unlock;



	do_for_each_ftrace_rec(pg, rec) {



		if (ftrace_match_module_record(rec, mod,

					       search, search_len, type)) {
@@ -1854,6 +1860,7 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) 
			ftrace_filtered = 1;



	} while_for_each_ftrace_rec();

 out_unlock:

	mutex_unlock(&ftrace_lock);



	return found;
@@ -2008,10 +2015,11 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 
		return -EINVAL;



	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)

			continue;

	if (unlikely(ftrace_disabled))

		goto out_unlock;



	do_for_each_ftrace_rec(pg, rec) {



		if (!ftrace_match_record(rec, search, len, type))

			continue;
@@ -2218,6 +2226,10 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, 


	mutex_lock(&ftrace_regex_lock);



	ret = -ENODEV;

	if (unlikely(ftrace_disabled))

		goto out_unlock;



	if (file->f_mode & FMODE_READ) {

		struct seq_file *m = file->private_data;

		iter = m->private;
@@ -2545,9 +2557,6 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) 
	bool exists;

	int i;



	if (ftrace_disabled)

		return -ENODEV;



	/* decode regex */

	type = filter_parse_regex(buffer, strlen(buffer), &search, &not);

	if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
@@ -2556,9 +2565,15 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) 
	search_len = strlen(search);



	mutex_lock(&ftrace_lock);



	if (unlikely(ftrace_disabled)) {

		mutex_unlock(&ftrace_lock);

		return -ENODEV;

	}



	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))

		if (rec->flags & FTRACE_FL_FREE)

			continue;



		if (ftrace_match_record(rec, search, search_len, type)) {
@@ -2700,10 +2715,11 @@ void ftrace_release_mod(struct module *mod) 
	struct dyn_ftrace *rec;

	struct ftrace_page *pg;



	mutex_lock(&ftrace_lock);



	if (ftrace_disabled)

		return;

		goto out_unlock;



	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {

		if (within_module_core(rec->ip, mod)) {

			/*
@@ -2714,6 +2730,7 @@ void ftrace_release_mod(struct module *mod) 
			ftrace_free_rec(rec);

		}

	} while_for_each_ftrace_rec();

 out_unlock:

	mutex_unlock(&ftrace_lock);

}
@@ -3108,16 +3125,17 @@ void ftrace_kill(void) 
 */

int register_ftrace_function(struct ftrace_ops *ops)

{

	int ret;



	if (unlikely(ftrace_disabled))

		return -1;

	int ret = -1;



	mutex_lock(&ftrace_lock);



	if (unlikely(ftrace_disabled))

		goto out_unlock;



	ret = __register_ftrace_function(ops);

	ftrace_startup(0);



 out_unlock:

	mutex_unlock(&ftrace_lock);

	return ret;

}
@@ -3145,13 +3163,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, 
		     void __user *buffer, size_t *lenp,

		     loff_t *ppos)

{

	int ret;



	if (unlikely(ftrace_disabled))

		return -ENODEV;

	int ret = -ENODEV;



	mutex_lock(&ftrace_lock);



	if (unlikely(ftrace_disabled))

		goto out;



	ret = proc_dointvec(table, write, buffer, lenp, ppos);



	if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))