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Commit ff288b27 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
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tracing/ftrace: fix a memory leak in stat tracing 



Impact: fix memory leak

This patch fixes a memory leak inside reset_stat_list(). The freeing
loop iterated only once.

Also turn the stat_list into a simple struct list_head, which
simplify the code and avoid an unused static pointer.

Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 431aa3fb

kernel/trace/trace_stat.c

+15 −24
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ struct trace_stat_list { 
	void *stat;

};



static struct trace_stat_list stat_list;

static LIST_HEAD(stat_list);



/*

 * This is a copy of the current tracer to avoid racy
@@ -39,22 +39,12 @@ static DEFINE_MUTEX(stat_list_mutex); 


static void reset_stat_list(void)

{

	struct trace_stat_list *node;

	struct list_head *next;

	struct trace_stat_list *node, *next;



	if (list_empty(&stat_list.list))

		return;



	node = list_entry(stat_list.list.next, struct trace_stat_list, list);

	next = node->list.next;



	while (&node->list != next) {

		kfree(node);

		node = list_entry(next, struct trace_stat_list, list);

	}

	list_for_each_entry_safe(node, next, &stat_list, list)

		kfree(node);



	INIT_LIST_HEAD(&stat_list.list);

	INIT_LIST_HEAD(&stat_list);

}



void init_tracer_stat(struct tracer *trace)
@@ -107,7 +97,7 @@ static int stat_seq_init(void) 
	}



	INIT_LIST_HEAD(&new_entry->list);

	list_add(&new_entry->list, &stat_list.list);

	list_add(&new_entry->list, &stat_list);

	new_entry->stat = current_tracer.stat_start();



	prev_stat = new_entry->stat;
@@ -130,7 +120,7 @@ static int stat_seq_init(void) 
		if (!new_entry->stat)

			break;



		list_for_each_entry(iter_entry, &stat_list.list, list) {

		list_for_each_entry(iter_entry, &stat_list, list) {

			/* Insertion with a descendent sorting */

			if (current_tracer.stat_cmp(new_entry->stat,

						iter_entry->stat) > 0) {
@@ -141,7 +131,7 @@ static int stat_seq_init(void) 


			/* The current smaller value */

			} else if (list_is_last(&iter_entry->list,

						&stat_list.list)) {

						&stat_list)) {

				list_add(&new_entry->list, &iter_entry->list);

				break;

			}
@@ -162,7 +152,7 @@ static int stat_seq_init(void) 


static void *stat_seq_start(struct seq_file *s, loff_t *pos)

{

	struct trace_stat_list *l = (struct trace_stat_list *)s->private;

	struct list_head *l = (struct list_head *)s->private;



	/* Prevent from tracer switch or stat_list modification */

	mutex_lock(&stat_list_mutex);
@@ -171,14 +161,14 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos) 
	if (!*pos && current_tracer.stat_headers)

		current_tracer.stat_headers(s);



	return seq_list_start(&l->list, *pos);

	return seq_list_start(l, *pos);

}



static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos)

{

	struct trace_stat_list *l = (struct trace_stat_list *)s->private;

	struct list_head *l = (struct list_head *)s->private;



	return seq_list_next(p, &l->list, pos);

	return seq_list_next(p, l, pos);

}



static void stat_seq_stop(struct seq_file *m, void *p)
@@ -188,8 +178,10 @@ static void stat_seq_stop(struct seq_file *m, void *p) 


static int stat_seq_show(struct seq_file *s, void *v)

{

	struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list);

	return current_tracer.stat_show(s, l->stat);

	struct trace_stat_list *entry =

		list_entry(v, struct trace_stat_list, list);



	return current_tracer.stat_show(s, entry->stat);

}



static const struct seq_operations trace_stat_seq_ops = {
@@ -237,7 +229,6 @@ static int __init tracing_stat_init(void) 
	struct dentry *d_tracing;

	struct dentry *entry;



	INIT_LIST_HEAD(&stat_list.list);

	d_tracing = tracing_init_dentry();



	entry = debugfs_create_file("trace_stat", 0444, d_tracing,