1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/cpu.h>
4
5 #include "notifier-error-inject.h"
6
7 static int priority;
8 module_param(priority, int, 0);
9 MODULE_PARM_DESC(priority, "specify cpu notifier priority");
10
11 #define UP_PREPARE 0
12 #define UP_PREPARE_FROZEN 0
13 #define DOWN_PREPARE 0
14 #define DOWN_PREPARE_FROZEN 0
15
16 static struct notifier_err_inject cpu_notifier_err_inject = {
17 .actions = {
18 { NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE) },
19 { NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE_FROZEN) },
20 { NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE) },
21 { NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE_FROZEN) },
22 {}
23 }
24 };
25
notf_err_handle(struct notifier_err_inject_action * action)26 static int notf_err_handle(struct notifier_err_inject_action *action)
27 {
28 int ret;
29
30 ret = action->error;
31 if (ret)
32 pr_info("Injecting error (%d) to %s\n", ret, action->name);
33 return ret;
34 }
35
notf_err_inj_up_prepare(unsigned int cpu)36 static int notf_err_inj_up_prepare(unsigned int cpu)
37 {
38 if (!cpuhp_tasks_frozen)
39 return notf_err_handle(&cpu_notifier_err_inject.actions[0]);
40 else
41 return notf_err_handle(&cpu_notifier_err_inject.actions[1]);
42 }
43
notf_err_inj_dead(unsigned int cpu)44 static int notf_err_inj_dead(unsigned int cpu)
45 {
46 if (!cpuhp_tasks_frozen)
47 return notf_err_handle(&cpu_notifier_err_inject.actions[2]);
48 else
49 return notf_err_handle(&cpu_notifier_err_inject.actions[3]);
50 }
51
52 static struct dentry *dir;
53
err_inject_init(void)54 static int err_inject_init(void)
55 {
56 int err;
57
58 dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
59 &cpu_notifier_err_inject, priority);
60 if (IS_ERR(dir))
61 return PTR_ERR(dir);
62
63 err = cpuhp_setup_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE,
64 "cpu-err-notif:prepare",
65 notf_err_inj_up_prepare,
66 notf_err_inj_dead);
67 if (err)
68 debugfs_remove_recursive(dir);
69
70 return err;
71 }
72
err_inject_exit(void)73 static void err_inject_exit(void)
74 {
75 cpuhp_remove_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE);
76 debugfs_remove_recursive(dir);
77 }
78
79 module_init(err_inject_init);
80 module_exit(err_inject_exit);
81
82 MODULE_DESCRIPTION("CPU notifier error injection module");
83 MODULE_LICENSE("GPL");
84 MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
85