1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_RATELIMIT_H
3 #define _LINUX_RATELIMIT_H
4
5 #include <linux/param.h>
6 #include <linux/sched.h>
7 #include <linux/spinlock.h>
8
9 #define DEFAULT_RATELIMIT_INTERVAL (5 * HZ)
10 #define DEFAULT_RATELIMIT_BURST 10
11
12 /* issue num suppressed message on exit */
13 #define RATELIMIT_MSG_ON_RELEASE BIT(0)
14
15 struct ratelimit_state {
16 raw_spinlock_t lock; /* protect the state */
17
18 int interval;
19 int burst;
20 int printed;
21 int missed;
22 unsigned long begin;
23 unsigned long flags;
24 };
25
26 #define RATELIMIT_STATE_INIT_FLAGS(name, interval_init, burst_init, flags_init) { \
27 .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
28 .interval = interval_init, \
29 .burst = burst_init, \
30 .flags = flags_init, \
31 }
32
33 #define RATELIMIT_STATE_INIT(name, interval_init, burst_init) \
34 RATELIMIT_STATE_INIT_FLAGS(name, interval_init, burst_init, 0)
35
36 #define RATELIMIT_STATE_INIT_DISABLED \
37 RATELIMIT_STATE_INIT(ratelimit_state, 0, DEFAULT_RATELIMIT_BURST)
38
39 #define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init) \
40 \
41 struct ratelimit_state name = \
42 RATELIMIT_STATE_INIT(name, interval_init, burst_init) \
43
ratelimit_state_init(struct ratelimit_state * rs,int interval,int burst)44 static inline void ratelimit_state_init(struct ratelimit_state *rs,
45 int interval, int burst)
46 {
47 memset(rs, 0, sizeof(*rs));
48
49 raw_spin_lock_init(&rs->lock);
50 rs->interval = interval;
51 rs->burst = burst;
52 }
53
ratelimit_default_init(struct ratelimit_state * rs)54 static inline void ratelimit_default_init(struct ratelimit_state *rs)
55 {
56 return ratelimit_state_init(rs, DEFAULT_RATELIMIT_INTERVAL,
57 DEFAULT_RATELIMIT_BURST);
58 }
59
ratelimit_state_exit(struct ratelimit_state * rs)60 static inline void ratelimit_state_exit(struct ratelimit_state *rs)
61 {
62 if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
63 return;
64
65 if (rs->missed) {
66 pr_warn("%s: %d output lines suppressed due to ratelimiting\n",
67 current->comm, rs->missed);
68 rs->missed = 0;
69 }
70 }
71
72 static inline void
ratelimit_set_flags(struct ratelimit_state * rs,unsigned long flags)73 ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
74 {
75 rs->flags = flags;
76 }
77
78 extern struct ratelimit_state printk_ratelimit_state;
79
80 extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
81 #define __ratelimit(state) ___ratelimit(state, __func__)
82
83 #ifdef CONFIG_PRINTK
84
85 #define WARN_ON_RATELIMIT(condition, state) ({ \
86 bool __rtn_cond = !!(condition); \
87 WARN_ON(__rtn_cond && __ratelimit(state)); \
88 __rtn_cond; \
89 })
90
91 #define WARN_RATELIMIT(condition, format, ...) \
92 ({ \
93 static DEFINE_RATELIMIT_STATE(_rs, \
94 DEFAULT_RATELIMIT_INTERVAL, \
95 DEFAULT_RATELIMIT_BURST); \
96 int rtn = !!(condition); \
97 \
98 if (unlikely(rtn && __ratelimit(&_rs))) \
99 WARN(rtn, format, ##__VA_ARGS__); \
100 \
101 rtn; \
102 })
103
104 #else
105
106 #define WARN_ON_RATELIMIT(condition, state) \
107 WARN_ON(condition)
108
109 #define WARN_RATELIMIT(condition, format, ...) \
110 ({ \
111 int rtn = WARN(condition, format, ##__VA_ARGS__); \
112 rtn; \
113 })
114
115 #endif
116
117 #endif /* _LINUX_RATELIMIT_H */
118