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
19 struct rcu_string {
20 struct rcu_head rcu;
21 char str[0];
22 };
23
rcu_string_strdup(const char * src,gfp_t mask)24 static 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
rcu_string_free(struct rcu_string * str)35 static 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