Messages in this thread | | | Date | Tue, 6 Jan 2009 15:43:09 -0500 (EST) | From | Steven Rostedt <> | Subject | Re: [PATCH] tracing/ftrace: fix a memory leak in stat tracing |
| |
Thanks Frederic!
I'll just add an Impact line to this and push it off to Ingo.
The impact line will simply be:
Impact: fix memory leak
-- Steve
On Tue, 6 Jan 2009, Frederic Weisbecker wrote:
> 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: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > --- > diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c > index 6f194a3..4cb4ff2 100644 > --- a/kernel/trace/trace_stat.c > +++ b/kernel/trace/trace_stat.c > @@ -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) { > + list_for_each_entry_safe(node, next, &stat_list, list) > kfree(node); > - node = list_entry(next, struct trace_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 @@ exit_free_list: > > 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, > -- > 1.6.0.4 > > > >
| |