dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / misc / lkdtm.c
blob11fdadc68e53e57722b4d58892fdf2c644beba34
1 /*
2 * Kprobe module for testing crash dumps
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright (C) IBM Corporation, 2006
20 * Author: Ankita Garg <ankita@in.ibm.com>
22 * This module induces system failures at predefined crashpoints to
23 * evaluate the reliability of crash dumps obtained using different dumping
24 * solutions.
26 * It is adapted from the Linux Kernel Dump Test Tool by
27 * Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
29 * Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
31 * See Documentation/fault-injection/provoke-crashes.txt for instructions
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 #include <linux/kernel.h>
36 #include <linux/fs.h>
37 #include <linux/module.h>
38 #include <linux/buffer_head.h>
39 #include <linux/kprobes.h>
40 #include <linux/list.h>
41 #include <linux/init.h>
42 #include <linux/interrupt.h>
43 #include <linux/hrtimer.h>
44 #include <linux/slab.h>
45 #include <scsi/scsi_cmnd.h>
46 #include <linux/debugfs.h>
47 #include <linux/vmalloc.h>
48 #include <linux/mman.h>
49 #include <asm/cacheflush.h>
51 #ifdef CONFIG_IDE
52 #include <linux/ide.h>
53 #endif
56 * Make sure our attempts to over run the kernel stack doesn't trigger
57 * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
58 * recurse past the end of THREAD_SIZE by default.
60 #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
61 #define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
62 #else
63 #define REC_STACK_SIZE (THREAD_SIZE / 8)
64 #endif
65 #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
67 #define DEFAULT_COUNT 10
68 #define EXEC_SIZE 64
70 enum cname {
71 CN_INVALID,
72 CN_INT_HARDWARE_ENTRY,
73 CN_INT_HW_IRQ_EN,
74 CN_INT_TASKLET_ENTRY,
75 CN_FS_DEVRW,
76 CN_MEM_SWAPOUT,
77 CN_TIMERADD,
78 CN_SCSI_DISPATCH_CMD,
79 CN_IDE_CORE_CP,
80 CN_DIRECT,
83 enum ctype {
84 CT_NONE,
85 CT_PANIC,
86 CT_BUG,
87 CT_WARNING,
88 CT_EXCEPTION,
89 CT_LOOP,
90 CT_OVERFLOW,
91 CT_CORRUPT_STACK,
92 CT_UNALIGNED_LOAD_STORE_WRITE,
93 CT_OVERWRITE_ALLOCATION,
94 CT_WRITE_AFTER_FREE,
95 CT_SOFTLOCKUP,
96 CT_HARDLOCKUP,
97 CT_SPINLOCKUP,
98 CT_HUNG_TASK,
99 CT_EXEC_DATA,
100 CT_EXEC_STACK,
101 CT_EXEC_KMALLOC,
102 CT_EXEC_VMALLOC,
103 CT_EXEC_USERSPACE,
104 CT_ACCESS_USERSPACE,
105 CT_WRITE_RO,
106 CT_WRITE_KERN,
109 static char* cp_name[] = {
110 "INT_HARDWARE_ENTRY",
111 "INT_HW_IRQ_EN",
112 "INT_TASKLET_ENTRY",
113 "FS_DEVRW",
114 "MEM_SWAPOUT",
115 "TIMERADD",
116 "SCSI_DISPATCH_CMD",
117 "IDE_CORE_CP",
118 "DIRECT",
121 static char* cp_type[] = {
122 "PANIC",
123 "BUG",
124 "WARNING",
125 "EXCEPTION",
126 "LOOP",
127 "OVERFLOW",
128 "CORRUPT_STACK",
129 "UNALIGNED_LOAD_STORE_WRITE",
130 "OVERWRITE_ALLOCATION",
131 "WRITE_AFTER_FREE",
132 "SOFTLOCKUP",
133 "HARDLOCKUP",
134 "SPINLOCKUP",
135 "HUNG_TASK",
136 "EXEC_DATA",
137 "EXEC_STACK",
138 "EXEC_KMALLOC",
139 "EXEC_VMALLOC",
140 "EXEC_USERSPACE",
141 "ACCESS_USERSPACE",
142 "WRITE_RO",
143 "WRITE_KERN",
146 static struct jprobe lkdtm;
148 static int lkdtm_parse_commandline(void);
149 static void lkdtm_handler(void);
151 static char* cpoint_name;
152 static char* cpoint_type;
153 static int cpoint_count = DEFAULT_COUNT;
154 static int recur_count = REC_NUM_DEFAULT;
156 static enum cname cpoint = CN_INVALID;
157 static enum ctype cptype = CT_NONE;
158 static int count = DEFAULT_COUNT;
159 static DEFINE_SPINLOCK(count_lock);
160 static DEFINE_SPINLOCK(lock_me_up);
162 static u8 data_area[EXEC_SIZE];
164 static const unsigned long rodata = 0xAA55AA55;
166 module_param(recur_count, int, 0644);
167 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
168 module_param(cpoint_name, charp, 0444);
169 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
170 module_param(cpoint_type, charp, 0444);
171 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
172 "hitting the crash point");
173 module_param(cpoint_count, int, 0644);
174 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
175 "crash point is to be hit to trigger action");
177 static unsigned int jp_do_irq(unsigned int irq)
179 lkdtm_handler();
180 jprobe_return();
181 return 0;
184 static irqreturn_t jp_handle_irq_event(unsigned int irq,
185 struct irqaction *action)
187 lkdtm_handler();
188 jprobe_return();
189 return 0;
192 static void jp_tasklet_action(struct softirq_action *a)
194 lkdtm_handler();
195 jprobe_return();
198 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
200 lkdtm_handler();
201 jprobe_return();
204 struct scan_control;
206 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
207 struct zone *zone,
208 struct scan_control *sc)
210 lkdtm_handler();
211 jprobe_return();
212 return 0;
215 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
216 const enum hrtimer_mode mode)
218 lkdtm_handler();
219 jprobe_return();
220 return 0;
223 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
225 lkdtm_handler();
226 jprobe_return();
227 return 0;
230 #ifdef CONFIG_IDE
231 static int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
232 struct block_device *bdev, unsigned int cmd,
233 unsigned long arg)
235 lkdtm_handler();
236 jprobe_return();
237 return 0;
239 #endif
241 /* Return the crashpoint number or NONE if the name is invalid */
242 static enum ctype parse_cp_type(const char *what, size_t count)
244 int i;
246 for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
247 if (!strcmp(what, cp_type[i]))
248 return i + 1;
251 return CT_NONE;
254 static const char *cp_type_to_str(enum ctype type)
256 if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
257 return "None";
259 return cp_type[type - 1];
262 static const char *cp_name_to_str(enum cname name)
264 if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
265 return "INVALID";
267 return cp_name[name - 1];
271 static int lkdtm_parse_commandline(void)
273 int i;
274 unsigned long flags;
276 if (cpoint_count < 1 || recur_count < 1)
277 return -EINVAL;
279 spin_lock_irqsave(&count_lock, flags);
280 count = cpoint_count;
281 spin_unlock_irqrestore(&count_lock, flags);
283 /* No special parameters */
284 if (!cpoint_type && !cpoint_name)
285 return 0;
287 /* Neither or both of these need to be set */
288 if (!cpoint_type || !cpoint_name)
289 return -EINVAL;
291 cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
292 if (cptype == CT_NONE)
293 return -EINVAL;
295 for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
296 if (!strcmp(cpoint_name, cp_name[i])) {
297 cpoint = i + 1;
298 return 0;
302 /* Could not find a valid crash point */
303 return -EINVAL;
306 static int recursive_loop(int remaining)
308 char buf[REC_STACK_SIZE];
310 /* Make sure compiler does not optimize this away. */
311 memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
312 if (!remaining)
313 return 0;
314 else
315 return recursive_loop(remaining - 1);
318 static void do_nothing(void)
320 return;
323 /* Must immediately follow do_nothing for size calculuations to work out. */
324 static void do_overwritten(void)
326 pr_info("do_overwritten wasn't overwritten!\n");
327 return;
330 static noinline void corrupt_stack(void)
332 /* Use default char array length that triggers stack protection. */
333 char data[8];
335 memset((void *)data, 0, 64);
338 static void execute_location(void *dst)
340 void (*func)(void) = dst;
342 pr_info("attempting ok execution at %p\n", do_nothing);
343 do_nothing();
345 memcpy(dst, do_nothing, EXEC_SIZE);
346 flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE);
347 pr_info("attempting bad execution at %p\n", func);
348 func();
351 static void execute_user_location(void *dst)
353 /* Intentionally crossing kernel/user memory boundary. */
354 void (*func)(void) = dst;
356 pr_info("attempting ok execution at %p\n", do_nothing);
357 do_nothing();
359 if (copy_to_user((void __user *)dst, do_nothing, EXEC_SIZE))
360 return;
361 flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE);
362 pr_info("attempting bad execution at %p\n", func);
363 func();
366 static void lkdtm_do_action(enum ctype which)
368 switch (which) {
369 case CT_PANIC:
370 panic("dumptest");
371 break;
372 case CT_BUG:
373 BUG();
374 break;
375 case CT_WARNING:
376 WARN_ON(1);
377 break;
378 case CT_EXCEPTION:
379 *((int *) 0) = 0;
380 break;
381 case CT_LOOP:
382 for (;;)
384 break;
385 case CT_OVERFLOW:
386 (void) recursive_loop(recur_count);
387 break;
388 case CT_CORRUPT_STACK:
389 corrupt_stack();
390 break;
391 case CT_UNALIGNED_LOAD_STORE_WRITE: {
392 static u8 data[5] __attribute__((aligned(4))) = {1, 2,
393 3, 4, 5};
394 u32 *p;
395 u32 val = 0x12345678;
397 p = (u32 *)(data + 1);
398 if (*p == 0)
399 val = 0x87654321;
400 *p = val;
401 break;
403 case CT_OVERWRITE_ALLOCATION: {
404 size_t len = 1020;
405 u32 *data = kmalloc(len, GFP_KERNEL);
407 data[1024 / sizeof(u32)] = 0x12345678;
408 kfree(data);
409 break;
411 case CT_WRITE_AFTER_FREE: {
412 size_t len = 1024;
413 u32 *data = kmalloc(len, GFP_KERNEL);
415 kfree(data);
416 schedule();
417 memset(data, 0x78, len);
418 break;
420 case CT_SOFTLOCKUP:
421 preempt_disable();
422 for (;;)
423 cpu_relax();
424 break;
425 case CT_HARDLOCKUP:
426 local_irq_disable();
427 for (;;)
428 cpu_relax();
429 break;
430 case CT_SPINLOCKUP:
431 /* Must be called twice to trigger. */
432 spin_lock(&lock_me_up);
433 /* Let sparse know we intended to exit holding the lock. */
434 __release(&lock_me_up);
435 break;
436 case CT_HUNG_TASK:
437 set_current_state(TASK_UNINTERRUPTIBLE);
438 schedule();
439 break;
440 case CT_EXEC_DATA:
441 execute_location(data_area);
442 break;
443 case CT_EXEC_STACK: {
444 u8 stack_area[EXEC_SIZE];
445 execute_location(stack_area);
446 break;
448 case CT_EXEC_KMALLOC: {
449 u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
450 execute_location(kmalloc_area);
451 kfree(kmalloc_area);
452 break;
454 case CT_EXEC_VMALLOC: {
455 u32 *vmalloc_area = vmalloc(EXEC_SIZE);
456 execute_location(vmalloc_area);
457 vfree(vmalloc_area);
458 break;
460 case CT_EXEC_USERSPACE: {
461 unsigned long user_addr;
463 user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
464 PROT_READ | PROT_WRITE | PROT_EXEC,
465 MAP_ANONYMOUS | MAP_PRIVATE, 0);
466 if (user_addr >= TASK_SIZE) {
467 pr_warn("Failed to allocate user memory\n");
468 return;
470 execute_user_location((void *)user_addr);
471 vm_munmap(user_addr, PAGE_SIZE);
472 break;
474 case CT_ACCESS_USERSPACE: {
475 unsigned long user_addr, tmp = 0;
476 unsigned long *ptr;
478 user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
479 PROT_READ | PROT_WRITE | PROT_EXEC,
480 MAP_ANONYMOUS | MAP_PRIVATE, 0);
481 if (user_addr >= TASK_SIZE) {
482 pr_warn("Failed to allocate user memory\n");
483 return;
486 if (copy_to_user((void __user *)user_addr, &tmp, sizeof(tmp))) {
487 pr_warn("copy_to_user failed\n");
488 vm_munmap(user_addr, PAGE_SIZE);
489 return;
492 ptr = (unsigned long *)user_addr;
494 pr_info("attempting bad read at %p\n", ptr);
495 tmp = *ptr;
496 tmp += 0xc0dec0de;
498 pr_info("attempting bad write at %p\n", ptr);
499 *ptr = tmp;
501 vm_munmap(user_addr, PAGE_SIZE);
503 break;
505 case CT_WRITE_RO: {
506 unsigned long *ptr;
508 ptr = (unsigned long *)&rodata;
510 pr_info("attempting bad write at %p\n", ptr);
511 *ptr ^= 0xabcd1234;
513 break;
515 case CT_WRITE_KERN: {
516 size_t size;
517 unsigned char *ptr;
519 size = (unsigned long)do_overwritten -
520 (unsigned long)do_nothing;
521 ptr = (unsigned char *)do_overwritten;
523 pr_info("attempting bad %zu byte write at %p\n", size, ptr);
524 memcpy(ptr, (unsigned char *)do_nothing, size);
525 flush_icache_range((unsigned long)ptr,
526 (unsigned long)(ptr + size));
528 do_overwritten();
529 break;
531 case CT_NONE:
532 default:
533 break;
538 static void lkdtm_handler(void)
540 unsigned long flags;
541 bool do_it = false;
543 spin_lock_irqsave(&count_lock, flags);
544 count--;
545 pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
546 cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
548 if (count == 0) {
549 do_it = true;
550 count = cpoint_count;
552 spin_unlock_irqrestore(&count_lock, flags);
554 if (do_it)
555 lkdtm_do_action(cptype);
558 static int lkdtm_register_cpoint(enum cname which)
560 int ret;
562 cpoint = CN_INVALID;
563 if (lkdtm.entry != NULL)
564 unregister_jprobe(&lkdtm);
566 switch (which) {
567 case CN_DIRECT:
568 lkdtm_do_action(cptype);
569 return 0;
570 case CN_INT_HARDWARE_ENTRY:
571 lkdtm.kp.symbol_name = "do_IRQ";
572 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
573 break;
574 case CN_INT_HW_IRQ_EN:
575 lkdtm.kp.symbol_name = "handle_IRQ_event";
576 lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
577 break;
578 case CN_INT_TASKLET_ENTRY:
579 lkdtm.kp.symbol_name = "tasklet_action";
580 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
581 break;
582 case CN_FS_DEVRW:
583 lkdtm.kp.symbol_name = "ll_rw_block";
584 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
585 break;
586 case CN_MEM_SWAPOUT:
587 lkdtm.kp.symbol_name = "shrink_inactive_list";
588 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
589 break;
590 case CN_TIMERADD:
591 lkdtm.kp.symbol_name = "hrtimer_start";
592 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
593 break;
594 case CN_SCSI_DISPATCH_CMD:
595 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
596 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
597 break;
598 case CN_IDE_CORE_CP:
599 #ifdef CONFIG_IDE
600 lkdtm.kp.symbol_name = "generic_ide_ioctl";
601 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
602 #else
603 pr_info("Crash point not available\n");
604 return -EINVAL;
605 #endif
606 break;
607 default:
608 pr_info("Invalid Crash Point\n");
609 return -EINVAL;
612 cpoint = which;
613 if ((ret = register_jprobe(&lkdtm)) < 0) {
614 pr_info("Couldn't register jprobe\n");
615 cpoint = CN_INVALID;
618 return ret;
621 static ssize_t do_register_entry(enum cname which, struct file *f,
622 const char __user *user_buf, size_t count, loff_t *off)
624 char *buf;
625 int err;
627 if (count >= PAGE_SIZE)
628 return -EINVAL;
630 buf = (char *)__get_free_page(GFP_KERNEL);
631 if (!buf)
632 return -ENOMEM;
633 if (copy_from_user(buf, user_buf, count)) {
634 free_page((unsigned long) buf);
635 return -EFAULT;
637 /* NULL-terminate and remove enter */
638 buf[count] = '\0';
639 strim(buf);
641 cptype = parse_cp_type(buf, count);
642 free_page((unsigned long) buf);
644 if (cptype == CT_NONE)
645 return -EINVAL;
647 err = lkdtm_register_cpoint(which);
648 if (err < 0)
649 return err;
651 *off += count;
653 return count;
656 /* Generic read callback that just prints out the available crash types */
657 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
658 size_t count, loff_t *off)
660 char *buf;
661 int i, n, out;
663 buf = (char *)__get_free_page(GFP_KERNEL);
664 if (buf == NULL)
665 return -ENOMEM;
667 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
668 for (i = 0; i < ARRAY_SIZE(cp_type); i++)
669 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
670 buf[n] = '\0';
672 out = simple_read_from_buffer(user_buf, count, off,
673 buf, n);
674 free_page((unsigned long) buf);
676 return out;
679 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
681 return 0;
685 static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
686 size_t count, loff_t *off)
688 return do_register_entry(CN_INT_HARDWARE_ENTRY, f, buf, count, off);
691 static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
692 size_t count, loff_t *off)
694 return do_register_entry(CN_INT_HW_IRQ_EN, f, buf, count, off);
697 static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
698 size_t count, loff_t *off)
700 return do_register_entry(CN_INT_TASKLET_ENTRY, f, buf, count, off);
703 static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
704 size_t count, loff_t *off)
706 return do_register_entry(CN_FS_DEVRW, f, buf, count, off);
709 static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
710 size_t count, loff_t *off)
712 return do_register_entry(CN_MEM_SWAPOUT, f, buf, count, off);
715 static ssize_t timeradd_entry(struct file *f, const char __user *buf,
716 size_t count, loff_t *off)
718 return do_register_entry(CN_TIMERADD, f, buf, count, off);
721 static ssize_t scsi_dispatch_cmd_entry(struct file *f,
722 const char __user *buf, size_t count, loff_t *off)
724 return do_register_entry(CN_SCSI_DISPATCH_CMD, f, buf, count, off);
727 static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
728 size_t count, loff_t *off)
730 return do_register_entry(CN_IDE_CORE_CP, f, buf, count, off);
733 /* Special entry to just crash directly. Available without KPROBEs */
734 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
735 size_t count, loff_t *off)
737 enum ctype type;
738 char *buf;
740 if (count >= PAGE_SIZE)
741 return -EINVAL;
742 if (count < 1)
743 return -EINVAL;
745 buf = (char *)__get_free_page(GFP_KERNEL);
746 if (!buf)
747 return -ENOMEM;
748 if (copy_from_user(buf, user_buf, count)) {
749 free_page((unsigned long) buf);
750 return -EFAULT;
752 /* NULL-terminate and remove enter */
753 buf[count] = '\0';
754 strim(buf);
756 type = parse_cp_type(buf, count);
757 free_page((unsigned long) buf);
758 if (type == CT_NONE)
759 return -EINVAL;
761 pr_info("Performing direct entry %s\n", cp_type_to_str(type));
762 lkdtm_do_action(type);
763 *off += count;
765 return count;
768 struct crash_entry {
769 const char *name;
770 const struct file_operations fops;
773 static const struct crash_entry crash_entries[] = {
774 {"DIRECT", {.read = lkdtm_debugfs_read,
775 .llseek = generic_file_llseek,
776 .open = lkdtm_debugfs_open,
777 .write = direct_entry} },
778 {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
779 .llseek = generic_file_llseek,
780 .open = lkdtm_debugfs_open,
781 .write = int_hardware_entry} },
782 {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
783 .llseek = generic_file_llseek,
784 .open = lkdtm_debugfs_open,
785 .write = int_hw_irq_en} },
786 {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
787 .llseek = generic_file_llseek,
788 .open = lkdtm_debugfs_open,
789 .write = int_tasklet_entry} },
790 {"FS_DEVRW", {.read = lkdtm_debugfs_read,
791 .llseek = generic_file_llseek,
792 .open = lkdtm_debugfs_open,
793 .write = fs_devrw_entry} },
794 {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
795 .llseek = generic_file_llseek,
796 .open = lkdtm_debugfs_open,
797 .write = mem_swapout_entry} },
798 {"TIMERADD", {.read = lkdtm_debugfs_read,
799 .llseek = generic_file_llseek,
800 .open = lkdtm_debugfs_open,
801 .write = timeradd_entry} },
802 {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
803 .llseek = generic_file_llseek,
804 .open = lkdtm_debugfs_open,
805 .write = scsi_dispatch_cmd_entry} },
806 {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
807 .llseek = generic_file_llseek,
808 .open = lkdtm_debugfs_open,
809 .write = ide_core_cp_entry} },
812 static struct dentry *lkdtm_debugfs_root;
814 static int __init lkdtm_module_init(void)
816 int ret = -EINVAL;
817 int n_debugfs_entries = 1; /* Assume only the direct entry */
818 int i;
820 /* Register debugfs interface */
821 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
822 if (!lkdtm_debugfs_root) {
823 pr_err("creating root dir failed\n");
824 return -ENODEV;
827 #ifdef CONFIG_KPROBES
828 n_debugfs_entries = ARRAY_SIZE(crash_entries);
829 #endif
831 for (i = 0; i < n_debugfs_entries; i++) {
832 const struct crash_entry *cur = &crash_entries[i];
833 struct dentry *de;
835 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
836 NULL, &cur->fops);
837 if (de == NULL) {
838 pr_err("could not create %s\n", cur->name);
839 goto out_err;
843 if (lkdtm_parse_commandline() == -EINVAL) {
844 pr_info("Invalid command\n");
845 goto out_err;
848 if (cpoint != CN_INVALID && cptype != CT_NONE) {
849 ret = lkdtm_register_cpoint(cpoint);
850 if (ret < 0) {
851 pr_info("Invalid crash point %d\n", cpoint);
852 goto out_err;
854 pr_info("Crash point %s of type %s registered\n",
855 cpoint_name, cpoint_type);
856 } else {
857 pr_info("No crash points registered, enable through debugfs\n");
860 return 0;
862 out_err:
863 debugfs_remove_recursive(lkdtm_debugfs_root);
864 return ret;
867 static void __exit lkdtm_module_exit(void)
869 debugfs_remove_recursive(lkdtm_debugfs_root);
871 unregister_jprobe(&lkdtm);
872 pr_info("Crash point unregistered\n");
875 module_init(lkdtm_module_init);
876 module_exit(lkdtm_module_exit);
878 MODULE_LICENSE("GPL");
879 MODULE_DESCRIPTION("Kprobe module for testing crash dumps");