Commit | Line | Data |
---|---|---|
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 | 21 | |
fea6ac55 | 22 | static void do_simple_thread_func(int cnt, const char *fmt, ...) |
9cfe06f8 | 23 | { |
b466b133 | 24 | unsigned long bitmask[1] = {0xdeadbeefUL}; |
fea6ac55 | 25 | va_list va; |
4e20e3a6 SRRH |
26 | int array[6]; |
27 | int len = cnt % 5; | |
28 | int i; | |
29 | ||
9cfe06f8 SR |
30 | set_current_state(TASK_INTERRUPTIBLE); |
31 | schedule_timeout(HZ); | |
4e20e3a6 SRRH |
32 | |
33 | for (i = 0; i < len; i++) | |
34 | array[i] = i + 1; | |
35 | array[i] = 0; | |
36 | ||
fea6ac55 SRG |
37 | va_start(va, fmt); |
38 | ||
c4c7eb29 | 39 | /* Silly tracepoints */ |
4e20e3a6 | 40 | trace_foo_bar("hello", cnt, array, random_strings[len], |
fea6ac55 SRG |
41 | current->cpus_ptr, fmt, &va); |
42 | ||
43 | va_end(va); | |
c4c7eb29 | 44 | |
7496946a SRRH |
45 | trace_foo_with_template_simple("HELLO", cnt); |
46 | ||
c4c7eb29 | 47 | trace_foo_bar_with_cond("Some times print", cnt); |
7496946a SRRH |
48 | |
49 | trace_foo_with_template_cond("prints other times", cnt); | |
50 | ||
51 | trace_foo_with_template_print("I have to be different", cnt); | |
b466b133 | 52 | |
8230f27b | 53 | trace_foo_rel_loc("Hello __rel_loc", cnt, bitmask, current->cpus_ptr); |
9cfe06f8 SR |
54 | } |
55 | ||
fea6ac55 SRG |
56 | static void simple_thread_func(int cnt) |
57 | { | |
58 | do_simple_thread_func(cnt, "iter=%d", cnt); | |
59 | } | |
60 | ||
9cfe06f8 SR |
61 | static int simple_thread(void *arg) |
62 | { | |
63 | int cnt = 0; | |
64 | ||
65 | while (!kthread_should_stop()) | |
66 | simple_thread_func(cnt++); | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | static struct task_struct *simple_tsk; | |
6adc13f8 SRRH |
72 | static struct task_struct *simple_tsk_fn; |
73 | ||
74 | static void simple_thread_func_fn(int cnt) | |
75 | { | |
76 | set_current_state(TASK_INTERRUPTIBLE); | |
77 | schedule_timeout(HZ); | |
78 | ||
79 | /* More silly tracepoints */ | |
80 | trace_foo_bar_with_fn("Look at me", cnt); | |
7496946a | 81 | trace_foo_with_template_fn("Look at me too", cnt); |
6adc13f8 SRRH |
82 | } |
83 | ||
84 | static int simple_thread_fn(void *arg) | |
85 | { | |
86 | int cnt = 0; | |
87 | ||
88 | while (!kthread_should_stop()) | |
89 | simple_thread_func_fn(cnt++); | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static DEFINE_MUTEX(thread_mutex); | |
a0cb2b5c | 95 | static int simple_thread_cnt; |
6adc13f8 | 96 | |
8cf868af | 97 | int foo_bar_reg(void) |
6adc13f8 | 98 | { |
6575257c SRV |
99 | mutex_lock(&thread_mutex); |
100 | if (simple_thread_cnt++) | |
101 | goto out; | |
102 | ||
6adc13f8 SRRH |
103 | pr_info("Starting thread for foo_bar_fn\n"); |
104 | /* | |
105 | * We shouldn't be able to start a trace when the module is | |
106 | * unloading (there's other locks to prevent that). But | |
107 | * for consistency sake, we still take the thread_mutex. | |
108 | */ | |
6adc13f8 | 109 | simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); |
6575257c | 110 | out: |
6adc13f8 | 111 | mutex_unlock(&thread_mutex); |
8cf868af | 112 | return 0; |
6adc13f8 SRRH |
113 | } |
114 | ||
115 | void foo_bar_unreg(void) | |
116 | { | |
6adc13f8 | 117 | mutex_lock(&thread_mutex); |
6575257c SRV |
118 | if (--simple_thread_cnt) |
119 | goto out; | |
120 | ||
121 | pr_info("Killing thread for foo_bar_fn\n"); | |
6adc13f8 SRRH |
122 | if (simple_tsk_fn) |
123 | kthread_stop(simple_tsk_fn); | |
124 | simple_tsk_fn = NULL; | |
6575257c | 125 | out: |
6adc13f8 SRRH |
126 | mutex_unlock(&thread_mutex); |
127 | } | |
9cfe06f8 SR |
128 | |
129 | static int __init trace_event_init(void) | |
130 | { | |
131 | simple_tsk = kthread_run(simple_thread, NULL, "event-sample"); | |
132 | if (IS_ERR(simple_tsk)) | |
133 | return -1; | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | static void __exit trace_event_exit(void) | |
139 | { | |
140 | kthread_stop(simple_tsk); | |
6adc13f8 SRRH |
141 | mutex_lock(&thread_mutex); |
142 | if (simple_tsk_fn) | |
143 | kthread_stop(simple_tsk_fn); | |
144 | simple_tsk_fn = NULL; | |
145 | mutex_unlock(&thread_mutex); | |
9cfe06f8 SR |
146 | } |
147 | ||
148 | module_init(trace_event_init); | |
149 | module_exit(trace_event_exit); | |
150 | ||
151 | MODULE_AUTHOR("Steven Rostedt"); | |
152 | MODULE_DESCRIPTION("trace-events-sample"); | |
153 | MODULE_LICENSE("GPL"); |