lib/cpu-notifier-error-inject.c

   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
  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
  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
  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>");