d06fc4d5 |
1 | /* probe-example.c |
2 | * |
3 | * Connects a two functions to marker call sites. |
4 | * |
5 | * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
6 | * |
7 | * This file is released under the GPLv2. |
8 | * See the file COPYING for more details. |
9 | */ |
10 | |
11 | #include <linux/sched.h> |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> |
14 | #include <linux/marker.h> |
15 | #include <asm/atomic.h> |
16 | |
17 | #define NUM_PROBES (sizeof(probe_array) / sizeof(struct probe_data)) |
18 | |
19 | struct probe_data { |
20 | const char *name; |
21 | const char *format; |
22 | marker_probe_func *probe_func; |
23 | }; |
24 | |
25 | void probe_subsystem_event(const struct __mark_marker_c *mdata, |
26 | const char *format, ...) |
27 | { |
28 | va_list ap; |
29 | /* Declare args */ |
30 | unsigned int value; |
31 | const char *mystr; |
32 | int task_size, task_alignment; |
33 | struct task_struct *task; |
34 | |
35 | /* Assign args */ |
36 | va_start(ap, format); |
37 | value = va_arg(ap, typeof(value)); |
38 | mystr = va_arg(ap, typeof(mystr)); |
39 | task_size = va_arg(ap, typeof(task_size)); |
40 | task_alignment = va_arg(ap, typeof(task_alignment)); |
41 | task = va_arg(ap, typeof(task)); |
42 | |
43 | /* Call printk */ |
44 | printk("Value %u, string %s, current ptr %p\n", value, mystr, current); |
45 | |
46 | /* or count, check rights, serialize data in a buffer */ |
47 | |
48 | va_end(ap); |
49 | } |
50 | |
51 | atomic_t eventb_count = ATOMIC_INIT(0); |
52 | |
53 | void probe_subsystem_eventb(const struct __mark_marker_c *mdata, |
54 | const char *format, ...) |
55 | { |
56 | /* Increment counter */ |
57 | atomic_inc(&eventb_count); |
58 | } |
59 | |
60 | static struct probe_data probe_array[] = |
61 | { |
62 | { .name = "subsystem_event", |
63 | .format = "%d %s %*.*r", |
64 | .probe_func = probe_subsystem_event }, |
65 | { .name = "subsystem_eventb", |
66 | .format = MARK_NOARGS, |
67 | .probe_func = probe_subsystem_eventb }, |
68 | }; |
69 | |
70 | static int __init probe_init(void) |
71 | { |
72 | int result; |
73 | uint8_t eID; |
74 | |
75 | for (eID = 0; eID < NUM_PROBES; eID++) { |
76 | result = marker_set_probe(probe_array[eID].name, |
77 | probe_array[eID].format, |
78 | probe_array[eID].probe_func, &probe_array[eID]); |
79 | if (!result) |
80 | printk(KERN_INFO "Unable to register probe %s\n", |
81 | probe_array[eID].name); |
82 | } |
83 | return 0; |
84 | } |
85 | |
86 | static void __exit probe_fini(void) |
87 | { |
88 | uint8_t eID; |
89 | |
90 | for (eID = 0; eID < NUM_PROBES; eID++) { |
91 | marker_remove_probe(probe_array[eID].name); |
92 | } |
93 | synchronize_sched(); /* Wait for probes to finish */ |
94 | printk("Number of event b : %u\n", atomic_read(&eventb_count)); |
95 | } |
96 | |
97 | module_init(probe_init); |
98 | module_exit(probe_fini); |
99 | |
100 | MODULE_LICENSE("GPL"); |
101 | MODULE_AUTHOR("Mathieu Desnoyers"); |
102 | MODULE_DESCRIPTION("SUBSYSTEM Probe"); |