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
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
34 #include <linux/kernel.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>
48 #include <linux/ide.h>
51 #define DEFAULT_COUNT 10
52 #define REC_NUM_DEFAULT 10
75 UNALIGNED_LOAD_STORE_WRITE,
80 static char* cp_name[] = {
92 static char* cp_type[] = {
99 "UNALIGNED_LOAD_STORE_WRITE",
100 "OVERWRITE_ALLOCATION",
104 static struct jprobe lkdtm;
106 static int lkdtm_parse_commandline(void);
107 static void lkdtm_handler(void);
109 static char* cpoint_name;
110 static char* cpoint_type;
111 static int cpoint_count = DEFAULT_COUNT;
112 static int recur_count = REC_NUM_DEFAULT;
114 static enum cname cpoint = INVALID;
115 static enum ctype cptype = NONE;
116 static int count = DEFAULT_COUNT;
118 module_param(recur_count, int, 0644);
119 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
121 module_param(cpoint_name, charp, 0644);
122 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
123 module_param(cpoint_type, charp, 0644);
124 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
125 "hitting the crash point");
126 module_param(cpoint_count, int, 0644);
127 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
128 "crash point is to be hit to trigger action");
130 static unsigned int jp_do_irq(unsigned int irq)
137 static irqreturn_t jp_handle_irq_event(unsigned int irq,
138 struct irqaction *action)
145 static void jp_tasklet_action(struct softirq_action *a)
151 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
159 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
161 struct scan_control *sc)
168 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
169 const enum hrtimer_mode mode)
176 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
184 int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
185 struct block_device *bdev, unsigned int cmd,
194 /* Return the crashpoint number or NONE if the name is invalid */
195 static enum ctype parse_cp_type(const char *what, size_t count)
199 for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
200 if (!strcmp(what, cp_type[i]))
207 static const char *cp_type_to_str(enum ctype type)
209 if (type == NONE || type < 0 || type > ARRAY_SIZE(cp_type))
212 return cp_type[type - 1];
215 static const char *cp_name_to_str(enum cname name)
217 if (name == INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
220 return cp_name[name - 1];
224 static int lkdtm_parse_commandline(void)
228 if (cpoint_count < 1 || recur_count < 1)
231 count = cpoint_count;
233 /* No special parameters */
234 if (!cpoint_type && !cpoint_name)
237 /* Neither or both of these need to be set */
238 if (!cpoint_type || !cpoint_name)
241 cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
245 for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
246 if (!strcmp(cpoint_name, cp_name[i])) {
252 /* Could not find a valid crash point */
256 static int recursive_loop(int a)
260 memset(buf,0xFF,1024);
265 return recursive_loop(a);
268 static void lkdtm_do_action(enum ctype which)
285 (void) recursive_loop(0);
287 case CORRUPT_STACK: {
288 volatile u32 data[8];
289 volatile u32 *p = data;
294 case UNALIGNED_LOAD_STORE_WRITE: {
295 static u8 data[5] __attribute__((aligned(4))) = {1, 2,
298 u32 val = 0x12345678;
300 p = (u32 *)(data + 1);
306 case OVERWRITE_ALLOCATION: {
308 u32 *data = kmalloc(len, GFP_KERNEL);
310 data[1024 / sizeof(u32)] = 0x12345678;
314 case WRITE_AFTER_FREE: {
316 u32 *data = kmalloc(len, GFP_KERNEL);
320 memset(data, 0x78, len);
330 static void lkdtm_handler(void)
333 printk(KERN_INFO "lkdtm: Crash point %s of type %s hit, trigger in %d rounds\n",
334 cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
337 lkdtm_do_action(cptype);
338 count = cpoint_count;
342 static int lkdtm_register_cpoint(enum cname which)
347 if (lkdtm.entry != NULL)
348 unregister_jprobe(&lkdtm);
352 lkdtm_do_action(cptype);
354 case INT_HARDWARE_ENTRY:
355 lkdtm.kp.symbol_name = "do_IRQ";
356 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
359 lkdtm.kp.symbol_name = "handle_IRQ_event";
360 lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
362 case INT_TASKLET_ENTRY:
363 lkdtm.kp.symbol_name = "tasklet_action";
364 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
367 lkdtm.kp.symbol_name = "ll_rw_block";
368 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
371 lkdtm.kp.symbol_name = "shrink_inactive_list";
372 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
375 lkdtm.kp.symbol_name = "hrtimer_start";
376 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
378 case SCSI_DISPATCH_CMD:
379 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
380 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
384 lkdtm.kp.symbol_name = "generic_ide_ioctl";
385 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
387 printk(KERN_INFO "lkdtm: Crash point not available\n");
392 printk(KERN_INFO "lkdtm: Invalid Crash Point\n");
397 if ((ret = register_jprobe(&lkdtm)) < 0) {
398 printk(KERN_INFO "lkdtm: Couldn't register jprobe\n");
405 static ssize_t do_register_entry(enum cname which, struct file *f,
406 const char __user *user_buf, size_t count, loff_t *off)
411 if (count >= PAGE_SIZE)
414 buf = (char *)__get_free_page(GFP_KERNEL);
417 if (copy_from_user(buf, user_buf, count)) {
418 free_page((unsigned long) buf);
421 /* NULL-terminate and remove enter */
425 cptype = parse_cp_type(buf, count);
426 free_page((unsigned long) buf);
431 err = lkdtm_register_cpoint(which);
440 /* Generic read callback that just prints out the available crash types */
441 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
442 size_t count, loff_t *off)
447 buf = (char *)__get_free_page(GFP_KERNEL);
449 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
450 for (i = 0; i < ARRAY_SIZE(cp_type); i++)
451 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
454 out = simple_read_from_buffer(user_buf, count, off,
456 free_page((unsigned long) buf);
461 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
467 static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
468 size_t count, loff_t *off)
470 return do_register_entry(INT_HARDWARE_ENTRY, f, buf, count, off);
473 static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
474 size_t count, loff_t *off)
476 return do_register_entry(INT_HW_IRQ_EN, f, buf, count, off);
479 static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
480 size_t count, loff_t *off)
482 return do_register_entry(INT_TASKLET_ENTRY, f, buf, count, off);
485 static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
486 size_t count, loff_t *off)
488 return do_register_entry(FS_DEVRW, f, buf, count, off);
491 static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
492 size_t count, loff_t *off)
494 return do_register_entry(MEM_SWAPOUT, f, buf, count, off);
497 static ssize_t timeradd_entry(struct file *f, const char __user *buf,
498 size_t count, loff_t *off)
500 return do_register_entry(TIMERADD, f, buf, count, off);
503 static ssize_t scsi_dispatch_cmd_entry(struct file *f,
504 const char __user *buf, size_t count, loff_t *off)
506 return do_register_entry(SCSI_DISPATCH_CMD, f, buf, count, off);
509 static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
510 size_t count, loff_t *off)
512 return do_register_entry(IDE_CORE_CP, f, buf, count, off);
515 /* Special entry to just crash directly. Available without KPROBEs */
516 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
517 size_t count, loff_t *off)
522 if (count >= PAGE_SIZE)
527 buf = (char *)__get_free_page(GFP_KERNEL);
530 if (copy_from_user(buf, user_buf, count)) {
531 free_page((unsigned long) buf);
534 /* NULL-terminate and remove enter */
538 type = parse_cp_type(buf, count);
539 free_page((unsigned long) buf);
543 printk(KERN_INFO "lkdtm: Performing direct entry %s\n",
544 cp_type_to_str(type));
545 lkdtm_do_action(type);
553 const struct file_operations fops;
556 static const struct crash_entry crash_entries[] = {
557 {"DIRECT", {.read = lkdtm_debugfs_read,
558 .open = lkdtm_debugfs_open,
559 .write = direct_entry} },
560 {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
561 .open = lkdtm_debugfs_open,
562 .write = int_hardware_entry} },
563 {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
564 .open = lkdtm_debugfs_open,
565 .write = int_hw_irq_en} },
566 {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
567 .open = lkdtm_debugfs_open,
568 .write = int_tasklet_entry} },
569 {"FS_DEVRW", {.read = lkdtm_debugfs_read,
570 .open = lkdtm_debugfs_open,
571 .write = fs_devrw_entry} },
572 {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
573 .open = lkdtm_debugfs_open,
574 .write = mem_swapout_entry} },
575 {"TIMERADD", {.read = lkdtm_debugfs_read,
576 .open = lkdtm_debugfs_open,
577 .write = timeradd_entry} },
578 {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
579 .open = lkdtm_debugfs_open,
580 .write = scsi_dispatch_cmd_entry} },
581 {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
582 .open = lkdtm_debugfs_open,
583 .write = ide_core_cp_entry} },
586 static struct dentry *lkdtm_debugfs_root;
588 static int __init lkdtm_module_init(void)
591 int n_debugfs_entries = 1; /* Assume only the direct entry */
594 /* Register debugfs interface */
595 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
596 if (!lkdtm_debugfs_root) {
597 printk(KERN_ERR "lkdtm: creating root dir failed\n");
601 #ifdef CONFIG_KPROBES
602 n_debugfs_entries = ARRAY_SIZE(crash_entries);
605 for (i = 0; i < n_debugfs_entries; i++) {
606 const struct crash_entry *cur = &crash_entries[i];
609 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
612 printk(KERN_ERR "lkdtm: could not create %s\n",
618 if (lkdtm_parse_commandline() == -EINVAL) {
619 printk(KERN_INFO "lkdtm: Invalid command\n");
623 if (cpoint != INVALID && cptype != NONE) {
624 ret = lkdtm_register_cpoint(cpoint);
626 printk(KERN_INFO "lkdtm: Invalid crash point %d\n",
630 printk(KERN_INFO "lkdtm: Crash point %s of type %s registered\n",
631 cpoint_name, cpoint_type);
633 printk(KERN_INFO "lkdtm: No crash points registered, enable through debugfs\n");
639 debugfs_remove_recursive(lkdtm_debugfs_root);
643 static void __exit lkdtm_module_exit(void)
645 debugfs_remove_recursive(lkdtm_debugfs_root);
647 unregister_jprobe(&lkdtm);
648 printk(KERN_INFO "lkdtm: Crash point unregistered\n");
651 module_init(lkdtm_module_init);
652 module_exit(lkdtm_module_exit);
654 MODULE_LICENSE("GPL");