1 #include <linux/kernel.h>
2 #include <linux/cpu.h>
3 #include <linux/module.h>
4 #include <linux/notifier.h>
5
6 static int priority;
7 static int cpu_up_prepare_error;
8 static int cpu_down_prepare_error;
9
10 module_param(priority, int, 0);
11 MODULE_PARM_DESC(priority, "specify cpu notifier priority");
12
13 module_param(cpu_up_prepare_error, int, 0644);
14 MODULE_PARM_DESC(cpu_up_prepare_error,
15 "specify error code to inject CPU_UP_PREPARE action");
16
17 module_param(cpu_down_prepare_error, int, 0644);
18 MODULE_PARM_DESC(cpu_down_prepare_error,
19 "specify error code to inject CPU_DOWN_PREPARE action");
20
err_inject_cpu_callback(struct notifier_block * nfb,unsigned long action,void * hcpu)21 static int err_inject_cpu_callback(struct notifier_block *nfb,
22 unsigned long action, void *hcpu)
23 {
24 int err = 0;
25
26 switch (action) {
27 case CPU_UP_PREPARE:
28 case CPU_UP_PREPARE_FROZEN:
29 err = cpu_up_prepare_error;
30 break;
31 case CPU_DOWN_PREPARE:
32 case CPU_DOWN_PREPARE_FROZEN:
33 err = cpu_down_prepare_error;
34 break;
35 }
36 if (err)
37 printk(KERN_INFO "Injecting error (%d) at cpu notifier\n", err);
38
39 return notifier_from_errno(err);
40 }
41
42 static struct notifier_block err_inject_cpu_notifier = {
43 .notifier_call = err_inject_cpu_callback,
44 };
45
err_inject_init(void)46 static int err_inject_init(void)
47 {
48 err_inject_cpu_notifier.priority = priority;
49
50 return register_hotcpu_notifier(&err_inject_cpu_notifier);
51 }
52
err_inject_exit(void)53 static void err_inject_exit(void)
54 {
55 unregister_hotcpu_notifier(&err_inject_cpu_notifier);
56 }
57
58 module_init(err_inject_init);
59 module_exit(err_inject_exit);
60
61 MODULE_DESCRIPTION("CPU notifier error injection module");
62 MODULE_LICENSE("GPL");
63 MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
64