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