1/*
2 * Copyright (C) 2012 Red Hat.  All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19struct rcu_string {
20	struct rcu_head rcu;
21	char str[0];
22};
23
24static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
25{
26	size_t len = strlen(src) + 1;
27	struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) +
28					 (len * sizeof(char)), mask);
29	if (!ret)
30		return ret;
31	strncpy(ret->str, src, len);
32	return ret;
33}
34
35static inline void rcu_string_free(struct rcu_string *str)
36{
37	if (str)
38		kfree_rcu(str, rcu);
39}
40
41#define printk_in_rcu(fmt, ...) do {	\
42	rcu_read_lock();		\
43	printk(fmt, __VA_ARGS__);	\
44	rcu_read_unlock();		\
45} while (0)
46
47#define printk_ratelimited_in_rcu(fmt, ...) do {	\
48	rcu_read_lock();				\
49	printk_ratelimited(fmt, __VA_ARGS__);		\
50	rcu_read_unlock();				\
51} while (0)
52
53#define rcu_str_deref(rcu_str) ({				\
54	struct rcu_string *__str = rcu_dereference(rcu_str);	\
55	__str->str;						\
56})
57