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34#include <linux/kernel.h>
35#include <linux/fs.h>
36#include <linux/module.h>
37#include <linux/buffer_head.h>
38#include <linux/kprobes.h>
39#include <linux/list.h>
40#include <linux/init.h>
41#include <linux/interrupt.h>
42#include <linux/hrtimer.h>
43#include <linux/slab.h>
44#include <scsi/scsi_cmnd.h>
45#include <linux/debugfs.h>
46
47#ifdef CONFIG_IDE
48#include <linux/ide.h>
49#endif
50
51#define DEFAULT_COUNT 10
52#define REC_NUM_DEFAULT 10
53
54enum cname {
55 CN_INVALID,
56 CN_INT_HARDWARE_ENTRY,
57 CN_INT_HW_IRQ_EN,
58 CN_INT_TASKLET_ENTRY,
59 CN_FS_DEVRW,
60 CN_MEM_SWAPOUT,
61 CN_TIMERADD,
62 CN_SCSI_DISPATCH_CMD,
63 CN_IDE_CORE_CP,
64 CN_DIRECT,
65};
66
67enum ctype {
68 CT_NONE,
69 CT_PANIC,
70 CT_BUG,
71 CT_EXCEPTION,
72 CT_LOOP,
73 CT_OVERFLOW,
74 CT_CORRUPT_STACK,
75 CT_UNALIGNED_LOAD_STORE_WRITE,
76 CT_OVERWRITE_ALLOCATION,
77 CT_WRITE_AFTER_FREE,
78 CT_SOFTLOCKUP,
79 CT_HARDLOCKUP,
80 CT_HUNG_TASK,
81};
82
83static char* cp_name[] = {
84 "INT_HARDWARE_ENTRY",
85 "INT_HW_IRQ_EN",
86 "INT_TASKLET_ENTRY",
87 "FS_DEVRW",
88 "MEM_SWAPOUT",
89 "TIMERADD",
90 "SCSI_DISPATCH_CMD",
91 "IDE_CORE_CP",
92 "DIRECT",
93};
94
95static char* cp_type[] = {
96 "PANIC",
97 "BUG",
98 "EXCEPTION",
99 "LOOP",
100 "OVERFLOW",
101 "CORRUPT_STACK",
102 "UNALIGNED_LOAD_STORE_WRITE",
103 "OVERWRITE_ALLOCATION",
104 "WRITE_AFTER_FREE",
105 "SOFTLOCKUP",
106 "HARDLOCKUP",
107 "HUNG_TASK",
108};
109
110static struct jprobe lkdtm;
111
112static int lkdtm_parse_commandline(void);
113static void lkdtm_handler(void);
114
115static char* cpoint_name;
116static char* cpoint_type;
117static int cpoint_count = DEFAULT_COUNT;
118static int recur_count = REC_NUM_DEFAULT;
119
120static enum cname cpoint = CN_INVALID;
121static enum ctype cptype = CT_NONE;
122static int count = DEFAULT_COUNT;
123static DEFINE_SPINLOCK(count_lock);
124
125module_param(recur_count, int, 0644);
126MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
127 "default is 10");
128module_param(cpoint_name, charp, 0444);
129MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
130module_param(cpoint_type, charp, 0444);
131MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
132 "hitting the crash point");
133module_param(cpoint_count, int, 0644);
134MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
135 "crash point is to be hit to trigger action");
136
137static unsigned int jp_do_irq(unsigned int irq)
138{
139 lkdtm_handler();
140 jprobe_return();
141 return 0;
142}
143
144static irqreturn_t jp_handle_irq_event(unsigned int irq,
145 struct irqaction *action)
146{
147 lkdtm_handler();
148 jprobe_return();
149 return 0;
150}
151
152static void jp_tasklet_action(struct softirq_action *a)
153{
154 lkdtm_handler();
155 jprobe_return();
156}
157
158static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
159{
160 lkdtm_handler();
161 jprobe_return();
162}
163
164struct scan_control;
165
166static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
167 struct zone *zone,
168 struct scan_control *sc)
169{
170 lkdtm_handler();
171 jprobe_return();
172 return 0;
173}
174
175static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
176 const enum hrtimer_mode mode)
177{
178 lkdtm_handler();
179 jprobe_return();
180 return 0;
181}
182
183static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
184{
185 lkdtm_handler();
186 jprobe_return();
187 return 0;
188}
189
190#ifdef CONFIG_IDE
191int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
192 struct block_device *bdev, unsigned int cmd,
193 unsigned long arg)
194{
195 lkdtm_handler();
196 jprobe_return();
197 return 0;
198}
199#endif
200
201
202static enum ctype parse_cp_type(const char *what, size_t count)
203{
204 int i;
205
206 for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
207 if (!strcmp(what, cp_type[i]))
208 return i + 1;
209 }
210
211 return CT_NONE;
212}
213
214static const char *cp_type_to_str(enum ctype type)
215{
216 if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
217 return "None";
218
219 return cp_type[type - 1];
220}
221
222static const char *cp_name_to_str(enum cname name)
223{
224 if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
225 return "INVALID";
226
227 return cp_name[name - 1];
228}
229
230
231static int lkdtm_parse_commandline(void)
232{
233 int i;
234 unsigned long flags;
235
236 if (cpoint_count < 1 || recur_count < 1)
237 return -EINVAL;
238
239 spin_lock_irqsave(&count_lock, flags);
240 count = cpoint_count;
241 spin_unlock_irqrestore(&count_lock, flags);
242
243
244 if (!cpoint_type && !cpoint_name)
245 return 0;
246
247
248 if (!cpoint_type || !cpoint_name)
249 return -EINVAL;
250
251 cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
252 if (cptype == CT_NONE)
253 return -EINVAL;
254
255 for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
256 if (!strcmp(cpoint_name, cp_name[i])) {
257 cpoint = i + 1;
258 return 0;
259 }
260 }
261
262
263 return -EINVAL;
264}
265
266static int recursive_loop(int a)
267{
268 char buf[1024];
269
270 memset(buf,0xFF,1024);
271 recur_count--;
272 if (!recur_count)
273 return 0;
274 else
275 return recursive_loop(a);
276}
277
278static void lkdtm_do_action(enum ctype which)
279{
280 switch (which) {
281 case CT_PANIC:
282 panic("dumptest");
283 break;
284 case CT_BUG:
285 BUG();
286 break;
287 case CT_EXCEPTION:
288 *((int *) 0) = 0;
289 break;
290 case CT_LOOP:
291 for (;;)
292 ;
293 break;
294 case CT_OVERFLOW:
295 (void) recursive_loop(0);
296 break;
297 case CT_CORRUPT_STACK: {
298 volatile u32 data[8];
299 volatile u32 *p = data;
300
301 p[12] = 0x12345678;
302 break;
303 }
304 case CT_UNALIGNED_LOAD_STORE_WRITE: {
305 static u8 data[5] __attribute__((aligned(4))) = {1, 2,
306 3, 4, 5};
307 u32 *p;
308 u32 val = 0x12345678;
309
310 p = (u32 *)(data + 1);
311 if (*p == 0)
312 val = 0x87654321;
313 *p = val;
314 break;
315 }
316 case CT_OVERWRITE_ALLOCATION: {
317 size_t len = 1020;
318 u32 *data = kmalloc(len, GFP_KERNEL);
319
320 data[1024 / sizeof(u32)] = 0x12345678;
321 kfree(data);
322 break;
323 }
324 case CT_WRITE_AFTER_FREE: {
325 size_t len = 1024;
326 u32 *data = kmalloc(len, GFP_KERNEL);
327
328 kfree(data);
329 schedule();
330 memset(data, 0x78, len);
331 break;
332 }
333 case CT_SOFTLOCKUP:
334 preempt_disable();
335 for (;;)
336 cpu_relax();
337 break;
338 case CT_HARDLOCKUP:
339 local_irq_disable();
340 for (;;)
341 cpu_relax();
342 break;
343 case CT_HUNG_TASK:
344 set_current_state(TASK_UNINTERRUPTIBLE);
345 schedule();
346 break;
347 case CT_NONE:
348 default:
349 break;
350 }
351
352}
353
354static void lkdtm_handler(void)
355{
356 unsigned long flags;
357 bool do_it = false;
358
359 spin_lock_irqsave(&count_lock, flags);
360 count--;
361 printk(KERN_INFO "lkdtm: Crash point %s of type %s hit, trigger in %d rounds\n",
362 cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
363
364 if (count == 0) {
365 do_it = true;
366 count = cpoint_count;
367 }
368 spin_unlock_irqrestore(&count_lock, flags);
369
370 if (do_it)
371 lkdtm_do_action(cptype);
372}
373
374static int lkdtm_register_cpoint(enum cname which)
375{
376 int ret;
377
378 cpoint = CN_INVALID;
379 if (lkdtm.entry != NULL)
380 unregister_jprobe(&lkdtm);
381
382 switch (which) {
383 case CN_DIRECT:
384 lkdtm_do_action(cptype);
385 return 0;
386 case CN_INT_HARDWARE_ENTRY:
387 lkdtm.kp.symbol_name = "do_IRQ";
388 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
389 break;
390 case CN_INT_HW_IRQ_EN:
391 lkdtm.kp.symbol_name = "handle_IRQ_event";
392 lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
393 break;
394 case CN_INT_TASKLET_ENTRY:
395 lkdtm.kp.symbol_name = "tasklet_action";
396 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
397 break;
398 case CN_FS_DEVRW:
399 lkdtm.kp.symbol_name = "ll_rw_block";
400 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
401 break;
402 case CN_MEM_SWAPOUT:
403 lkdtm.kp.symbol_name = "shrink_inactive_list";
404 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
405 break;
406 case CN_TIMERADD:
407 lkdtm.kp.symbol_name = "hrtimer_start";
408 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
409 break;
410 case CN_SCSI_DISPATCH_CMD:
411 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
412 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
413 break;
414 case CN_IDE_CORE_CP:
415#ifdef CONFIG_IDE
416 lkdtm.kp.symbol_name = "generic_ide_ioctl";
417 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
418#else
419 printk(KERN_INFO "lkdtm: Crash point not available\n");
420 return -EINVAL;
421#endif
422 break;
423 default:
424 printk(KERN_INFO "lkdtm: Invalid Crash Point\n");
425 return -EINVAL;
426 }
427
428 cpoint = which;
429 if ((ret = register_jprobe(&lkdtm)) < 0) {
430 printk(KERN_INFO "lkdtm: Couldn't register jprobe\n");
431 cpoint = CN_INVALID;
432 }
433
434 return ret;
435}
436
437static ssize_t do_register_entry(enum cname which, struct file *f,
438 const char __user *user_buf, size_t count, loff_t *off)
439{
440 char *buf;
441 int err;
442
443 if (count >= PAGE_SIZE)
444 return -EINVAL;
445
446 buf = (char *)__get_free_page(GFP_KERNEL);
447 if (!buf)
448 return -ENOMEM;
449 if (copy_from_user(buf, user_buf, count)) {
450 free_page((unsigned long) buf);
451 return -EFAULT;
452 }
453
454 buf[count] = '\0';
455 strim(buf);
456
457 cptype = parse_cp_type(buf, count);
458 free_page((unsigned long) buf);
459
460 if (cptype == CT_NONE)
461 return -EINVAL;
462
463 err = lkdtm_register_cpoint(which);
464 if (err < 0)
465 return err;
466
467 *off += count;
468
469 return count;
470}
471
472
473static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
474 size_t count, loff_t *off)
475{
476 char *buf;
477 int i, n, out;
478
479 buf = (char *)__get_free_page(GFP_KERNEL);
480 if (buf == NULL)
481 return -ENOMEM;
482
483 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
484 for (i = 0; i < ARRAY_SIZE(cp_type); i++)
485 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
486 buf[n] = '\0';
487
488 out = simple_read_from_buffer(user_buf, count, off,
489 buf, n);
490 free_page((unsigned long) buf);
491
492 return out;
493}
494
495static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
496{
497 return 0;
498}
499
500
501static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
502 size_t count, loff_t *off)
503{
504 return do_register_entry(CN_INT_HARDWARE_ENTRY, f, buf, count, off);
505}
506
507static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
508 size_t count, loff_t *off)
509{
510 return do_register_entry(CN_INT_HW_IRQ_EN, f, buf, count, off);
511}
512
513static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
514 size_t count, loff_t *off)
515{
516 return do_register_entry(CN_INT_TASKLET_ENTRY, f, buf, count, off);
517}
518
519static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
520 size_t count, loff_t *off)
521{
522 return do_register_entry(CN_FS_DEVRW, f, buf, count, off);
523}
524
525static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
526 size_t count, loff_t *off)
527{
528 return do_register_entry(CN_MEM_SWAPOUT, f, buf, count, off);
529}
530
531static ssize_t timeradd_entry(struct file *f, const char __user *buf,
532 size_t count, loff_t *off)
533{
534 return do_register_entry(CN_TIMERADD, f, buf, count, off);
535}
536
537static ssize_t scsi_dispatch_cmd_entry(struct file *f,
538 const char __user *buf, size_t count, loff_t *off)
539{
540 return do_register_entry(CN_SCSI_DISPATCH_CMD, f, buf, count, off);
541}
542
543static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
544 size_t count, loff_t *off)
545{
546 return do_register_entry(CN_IDE_CORE_CP, f, buf, count, off);
547}
548
549
550static ssize_t direct_entry(struct file *f, const char __user *user_buf,
551 size_t count, loff_t *off)
552{
553 enum ctype type;
554 char *buf;
555
556 if (count >= PAGE_SIZE)
557 return -EINVAL;
558 if (count < 1)
559 return -EINVAL;
560
561 buf = (char *)__get_free_page(GFP_KERNEL);
562 if (!buf)
563 return -ENOMEM;
564 if (copy_from_user(buf, user_buf, count)) {
565 free_page((unsigned long) buf);
566 return -EFAULT;
567 }
568
569 buf[count] = '\0';
570 strim(buf);
571
572 type = parse_cp_type(buf, count);
573 free_page((unsigned long) buf);
574 if (type == CT_NONE)
575 return -EINVAL;
576
577 printk(KERN_INFO "lkdtm: Performing direct entry %s\n",
578 cp_type_to_str(type));
579 lkdtm_do_action(type);
580 *off += count;
581
582 return count;
583}
584
585struct crash_entry {
586 const char *name;
587 const struct file_operations fops;
588};
589
590static const struct crash_entry crash_entries[] = {
591 {"DIRECT", {.read = lkdtm_debugfs_read,
592 .llseek = generic_file_llseek,
593 .open = lkdtm_debugfs_open,
594 .write = direct_entry} },
595 {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
596 .llseek = generic_file_llseek,
597 .open = lkdtm_debugfs_open,
598 .write = int_hardware_entry} },
599 {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
600 .llseek = generic_file_llseek,
601 .open = lkdtm_debugfs_open,
602 .write = int_hw_irq_en} },
603 {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
604 .llseek = generic_file_llseek,
605 .open = lkdtm_debugfs_open,
606 .write = int_tasklet_entry} },
607 {"FS_DEVRW", {.read = lkdtm_debugfs_read,
608 .llseek = generic_file_llseek,
609 .open = lkdtm_debugfs_open,
610 .write = fs_devrw_entry} },
611 {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
612 .llseek = generic_file_llseek,
613 .open = lkdtm_debugfs_open,
614 .write = mem_swapout_entry} },
615 {"TIMERADD", {.read = lkdtm_debugfs_read,
616 .llseek = generic_file_llseek,
617 .open = lkdtm_debugfs_open,
618 .write = timeradd_entry} },
619 {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
620 .llseek = generic_file_llseek,
621 .open = lkdtm_debugfs_open,
622 .write = scsi_dispatch_cmd_entry} },
623 {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
624 .llseek = generic_file_llseek,
625 .open = lkdtm_debugfs_open,
626 .write = ide_core_cp_entry} },
627};
628
629static struct dentry *lkdtm_debugfs_root;
630
631static int __init lkdtm_module_init(void)
632{
633 int ret = -EINVAL;
634 int n_debugfs_entries = 1;
635 int i;
636
637
638 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
639 if (!lkdtm_debugfs_root) {
640 printk(KERN_ERR "lkdtm: creating root dir failed\n");
641 return -ENODEV;
642 }
643
644#ifdef CONFIG_KPROBES
645 n_debugfs_entries = ARRAY_SIZE(crash_entries);
646#endif
647
648 for (i = 0; i < n_debugfs_entries; i++) {
649 const struct crash_entry *cur = &crash_entries[i];
650 struct dentry *de;
651
652 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
653 NULL, &cur->fops);
654 if (de == NULL) {
655 printk(KERN_ERR "lkdtm: could not create %s\n",
656 cur->name);
657 goto out_err;
658 }
659 }
660
661 if (lkdtm_parse_commandline() == -EINVAL) {
662 printk(KERN_INFO "lkdtm: Invalid command\n");
663 goto out_err;
664 }
665
666 if (cpoint != CN_INVALID && cptype != CT_NONE) {
667 ret = lkdtm_register_cpoint(cpoint);
668 if (ret < 0) {
669 printk(KERN_INFO "lkdtm: Invalid crash point %d\n",
670 cpoint);
671 goto out_err;
672 }
673 printk(KERN_INFO "lkdtm: Crash point %s of type %s registered\n",
674 cpoint_name, cpoint_type);
675 } else {
676 printk(KERN_INFO "lkdtm: No crash points registered, enable through debugfs\n");
677 }
678
679 return 0;
680
681out_err:
682 debugfs_remove_recursive(lkdtm_debugfs_root);
683 return ret;
684}
685
686static void __exit lkdtm_module_exit(void)
687{
688 debugfs_remove_recursive(lkdtm_debugfs_root);
689
690 unregister_jprobe(&lkdtm);
691 printk(KERN_INFO "lkdtm: Crash point unregistered\n");
692}
693
694module_init(lkdtm_module_init);
695module_exit(lkdtm_module_exit);
696
697MODULE_LICENSE("GPL");
698
