From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753956AbZAFUdp (ORCPT ); Tue, 6 Jan 2009 15:33:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751798AbZAFUdg (ORCPT ); Tue, 6 Jan 2009 15:33:36 -0500 Received: from mail-bw0-f21.google.com ([209.85.218.21]:62516 "EHLO mail-bw0-f21.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbZAFUdf (ORCPT ); Tue, 6 Jan 2009 15:33:35 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=ui6H/h56nTlQH8U6UYUiv5c7Ns24/TWaTXzuJmXPYqSZPSzahzUfpM4hyRhqo3SySB dPRzaJ3pFzw7tJKJ5OwBi1Wqj6VW9FhC+KbBVzIiln8z0aQkM4FRryhi09mcx7h/NDtB 87iTcszHIiDN4i7c9amFs56+EbCiAcsoPy2n0= Date: Tue, 6 Jan 2009 21:33:30 +0100 From: Frederic Weisbecker To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, mingo@elte.hu Subject: [PATCH] tracing/ftrace: fix a memory leak in stat tracing Message-ID: <20090106203329.GA5922@nowhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Frederic Weisbecker --- 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