Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9cfe06f8 SR |
2 | #include <linux/module.h> |
3 | #include <linux/kthread.h> | |
4 | ||
5 | /* | |
6 | * Any file that uses trace points, must include the header. | |
7 | * But only one file, must include the header by defining | |
8 | * CREATE_TRACE_POINTS first. This will make the C code that | |
9 | * creates the handles for the trace points. | |
10 | */ | |
11 | #define CREATE_TRACE_POINTS | |
12 | #include "trace-events-sample.h" | |
13 | ||
4e20e3a6 SRRH |
14 | static const char *random_strings[] = { |
15 | "Mother Goose", | |
16 | "Snoopy", | |
17 | "Gandalf", | |
18 | "Frodo", | |
19 | "One ring to rule them all" | |
20 | }; | |
9cfe06f8 SR |
21 | |
22 | static void simple_thread_func(int cnt) | |
23 | { | |
4e20e3a6 SRRH |
24 | int array[6]; |
25 | int len = cnt % 5; | |
26 | int i; | |
27 | ||
9cfe06f8 SR |
28 | set_current_state(TASK_INTERRUPTIBLE); |
29 | schedule_timeout(HZ); | |
4e20e3a6 SRRH |
30 | |
31 | for (i = 0; i < len; i++) | |
32 | array[i] = i + 1; | |
33 | array[i] = 0; | |
34 | ||
c4c7eb29 | 35 | /* Silly tracepoints */ |
4e20e3a6 | 36 | trace_foo_bar("hello", cnt, array, random_strings[len], |
0c98d344 | 37 | ¤t->cpus_allowed); |
c4c7eb29 | 38 | |
7496946a SRRH |
39 | trace_foo_with_template_simple("HELLO", cnt); |
40 | ||
c4c7eb29 | 41 | trace_foo_bar_with_cond("Some times print", cnt); |
7496946a SRRH |
42 | |
43 | trace_foo_with_template_cond("prints other times", cnt); | |
44 | ||
45 | trace_foo_with_template_print("I have to be different", cnt); | |
9cfe06f8 SR |
46 | } |
47 | ||
48 | static int simple_thread(void *arg) | |
49 | { | |
50 | int cnt = 0; | |
51 | ||
52 | while (!kthread_should_stop()) | |
53 | simple_thread_func(cnt++); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static struct task_struct *simple_tsk; | |
6adc13f8 SRRH |
59 | static struct task_struct *simple_tsk_fn; |
60 | ||
61 | static void simple_thread_func_fn(int cnt) | |
62 | { | |
63 | set_current_state(TASK_INTERRUPTIBLE); | |
64 | schedule_timeout(HZ); | |
65 | ||
66 | /* More silly tracepoints */ | |
67 | trace_foo_bar_with_fn("Look at me", cnt); | |
7496946a | 68 | trace_foo_with_template_fn("Look at me too", cnt); |
6adc13f8 SRRH |
69 | } |
70 | ||
71 | static int simple_thread_fn(void *arg) | |
72 | { | |
73 | int cnt = 0; | |
74 | ||
75 | while (!kthread_should_stop()) | |
76 | simple_thread_func_fn(cnt++); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | static DEFINE_MUTEX(thread_mutex); | |
a0cb2b5c | 82 | static int simple_thread_cnt; |
6adc13f8 | 83 | |
8cf868af | 84 | int foo_bar_reg(void) |
6adc13f8 | 85 | { |
6575257c SRV |
86 | mutex_lock(&thread_mutex); |
87 | if (simple_thread_cnt++) | |
88 | goto out; | |
89 | ||
6adc13f8 SRRH |
90 | pr_info("Starting thread for foo_bar_fn\n"); |
91 | /* | |
92 | * We shouldn't be able to start a trace when the module is | |
93 | * unloading (there's other locks to prevent that). But | |
94 | * for consistency sake, we still take the thread_mutex. | |
95 | */ | |
6adc13f8 | 96 | simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); |
6575257c | 97 | out: |
6adc13f8 | 98 | mutex_unlock(&thread_mutex); |
8cf868af | 99 | return 0; |
6adc13f8 SRRH |
100 | } |
101 | ||
102 | void foo_bar_unreg(void) | |
103 | { | |
6adc13f8 | 104 | mutex_lock(&thread_mutex); |
6575257c SRV |
105 | if (--simple_thread_cnt) |
106 | goto out; | |
107 | ||
108 | pr_info("Killing thread for foo_bar_fn\n"); | |
6adc13f8 SRRH |
109 | if (simple_tsk_fn) |
110 | kthread_stop(simple_tsk_fn); | |
111 | simple_tsk_fn = NULL; | |
6575257c | 112 | out: |
6adc13f8 SRRH |
113 | mutex_unlock(&thread_mutex); |
114 | } | |
9cfe06f8 SR |
115 | |
116 | static int __init trace_event_init(void) | |
117 | { | |
118 | simple_tsk = kthread_run(simple_thread, NULL, "event-sample"); | |
119 | if (IS_ERR(simple_tsk)) | |
120 | return -1; | |
121 | ||
122 | return 0; | |
123 | } | |
124 | ||
125 | static void __exit trace_event_exit(void) | |
126 | { | |
127 | kthread_stop(simple_tsk); | |
6adc13f8 SRRH |
128 | mutex_lock(&thread_mutex); |
129 | if (simple_tsk_fn) | |
130 | kthread_stop(simple_tsk_fn); | |
131 | simple_tsk_fn = NULL; | |
132 | mutex_unlock(&thread_mutex); | |
9cfe06f8 SR |
133 | } |
134 | ||
135 | module_init(trace_event_init); | |
136 | module_exit(trace_event_exit); | |
137 | ||
138 | MODULE_AUTHOR("Steven Rostedt"); | |
139 | MODULE_DESCRIPTION("trace-events-sample"); | |
140 | MODULE_LICENSE("GPL"); |