fs/proc/breakme.c

   1 #include <linux/cpumask.h>
   2 #include <linux/fs.h>
   3 #include <linux/gfp.h>
   4 #include <linux/init.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/kernel_stat.h>
   7 #include <linux/proc_fs.h>
   8 #include <linux/sched.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/slab.h>
  11 #include <linux/time.h>
  12 #include <linux/irqnr.h>
  13 #include <asm/cputime.h>
  14 #include <asm/uaccess.h>
  15
  16 #define MAX_BREAKME_WRITE 64
  17 static ssize_t write_breakme(struct file *file, const char __user *buf,
  18                                    size_t count, loff_t *ppos)
  19 {
  20         char kbuf[MAX_BREAKME_WRITE + 1];
  21         DEFINE_SPINLOCK(lock_me_up);
  22
  23         if (count) {
  24                 if (count > MAX_BREAKME_WRITE)
  25                         return -EINVAL;
  26                 if (copy_from_user(&kbuf, buf, count))
  27                         return -EFAULT;
  28                 kbuf[min(count, sizeof(kbuf))-1] = '\0';
  29
  30                 /* Null pointer dereference */
  31                 if (!strcmp(kbuf, "nullptr"))
  32                         *(unsigned long *)0 = 0;
  33                 /* BUG() */
  34                 else if (!strcmp(kbuf, "bug"))
  35                         BUG();
  36                 /* hung_task stuck in unkillable D state */
  37                 else if (!strcmp(kbuf, "hungtask"))
  38                         schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
  39                 /* Panic */
  40                 else if (!strcmp(kbuf, "panic"))
  41                         panic("Testing panic");
  42                 /* Set up a deadlock (call this twice) */
  43                 else if (!strcmp(kbuf, "deadlock"))
  44                         spin_lock(&lock_me_up);
  45                 /* lockup */
  46                 else if (!strcmp(kbuf, "softlockup")) {
  47                         while (1)
  48                                 ;
  49                 }
  50                 /* lockup with interrupts enabled */
  51                 else if (!strcmp(kbuf, "irqlockup")) {
  52                         spin_lock(&lock_me_up);
  53                         while (1)
  54                                 ;
  55                 }
  56                 /* lockup with interrupts disabled */
  57                 else if (!strcmp(kbuf, "nmiwatchdog")) {
  58                         spin_lock_irq(&lock_me_up);
  59                         while (1)
  60                                 ;
  61                 }
  62         }
  63         return count;
  64 }
  65
  66 static struct file_operations proc_breakme_operations = {
  67         .write          = write_breakme,
  68 };
  69
  70 void __init proc_breakme_init(void)
  71 {
  72         proc_create("breakme", S_IWUSR, NULL, &proc_breakme_operations);
  73 }