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(name, interval_init, burst_init) { \ |
27 | .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \ |
28 | .interval = interval_init, \ |
29 | .burst = burst_init, \ |
30 | } |
31 | |
32 | #define RATELIMIT_STATE_INIT_DISABLED \ |
33 | RATELIMIT_STATE_INIT(ratelimit_state, 0, DEFAULT_RATELIMIT_BURST) |
34 | |
35 | #define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init) \ |
36 | \ |
37 | struct ratelimit_state name = \ |
38 | RATELIMIT_STATE_INIT(name, interval_init, burst_init) \ |
39 | |
40 | static inline void ratelimit_state_init(struct ratelimit_state *rs, |
41 | int interval, int burst) |
42 | { |
43 | memset(rs, 0, sizeof(*rs)); |
44 | |
45 | raw_spin_lock_init(&rs->lock); |
46 | rs->interval = interval; |
47 | rs->burst = burst; |
48 | } |
49 | |
50 | static inline void ratelimit_default_init(struct ratelimit_state *rs) |
51 | { |
52 | return ratelimit_state_init(rs, DEFAULT_RATELIMIT_INTERVAL, |
53 | DEFAULT_RATELIMIT_BURST); |
54 | } |
55 | |
56 | static inline void ratelimit_state_exit(struct ratelimit_state *rs) |
57 | { |
58 | if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) |
59 | return; |
60 | |
61 | if (rs->missed) { |
62 | pr_warn("%s: %d output lines suppressed due to ratelimiting\n" , |
63 | current->comm, rs->missed); |
64 | rs->missed = 0; |
65 | } |
66 | } |
67 | |
68 | static inline void |
69 | ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags) |
70 | { |
71 | rs->flags = flags; |
72 | } |
73 | |
74 | extern struct ratelimit_state printk_ratelimit_state; |
75 | |
76 | extern int ___ratelimit(struct ratelimit_state *rs, const char *func); |
77 | #define __ratelimit(state) ___ratelimit(state, __func__) |
78 | |
79 | #ifdef CONFIG_PRINTK |
80 | |
81 | #define WARN_ON_RATELIMIT(condition, state) ({ \ |
82 | bool __rtn_cond = !!(condition); \ |
83 | WARN_ON(__rtn_cond && __ratelimit(state)); \ |
84 | __rtn_cond; \ |
85 | }) |
86 | |
87 | #define WARN_RATELIMIT(condition, format, ...) \ |
88 | ({ \ |
89 | static DEFINE_RATELIMIT_STATE(_rs, \ |
90 | DEFAULT_RATELIMIT_INTERVAL, \ |
91 | DEFAULT_RATELIMIT_BURST); \ |
92 | int rtn = !!(condition); \ |
93 | \ |
94 | if (unlikely(rtn && __ratelimit(&_rs))) \ |
95 | WARN(rtn, format, ##__VA_ARGS__); \ |
96 | \ |
97 | rtn; \ |
98 | }) |
99 | |
100 | #else |
101 | |
102 | #define WARN_ON_RATELIMIT(condition, state) \ |
103 | WARN_ON(condition) |
104 | |
105 | #define WARN_RATELIMIT(condition, format, ...) \ |
106 | ({ \ |
107 | int rtn = WARN(condition, format, ##__VA_ARGS__); \ |
108 | rtn; \ |
109 | }) |
110 | |
111 | #endif |
112 | |
113 | #endif /* _LINUX_RATELIMIT_H */ |
114 | |