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 <scsi/scsi_cmnd.h>
44 #include <linux/debugfs.h>
47 #include <linux/ide.h>
50 #define DEFAULT_COUNT 10
51 #define REC_NUM_DEFAULT 10
74 UNALIGNED_LOAD_STORE_WRITE,
79 static char* cp_name[] = {
91 static char* cp_type[] = {
98 "UNALIGNED_LOAD_STORE_WRITE",
99 "OVERWRITE_ALLOCATION",
103 static struct jprobe lkdtm;
105 static int lkdtm_parse_commandline(void);
106 static void lkdtm_handler(void);
108 static char* cpoint_name;
109 static char* cpoint_type;
110 static int cpoint_count = DEFAULT_COUNT;
111 static int recur_count = REC_NUM_DEFAULT;
113 static enum cname cpoint = INVALID;
114 static enum ctype cptype = NONE;
115 static int count = DEFAULT_COUNT;
117 module_param(recur_count, int, 0644);
118 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
120 module_param(cpoint_name, charp, 0644);
121 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
122 module_param(cpoint_type, charp, 0644);
123 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
124 "hitting the crash point");
125 module_param(cpoint_count, int, 0644);
126 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
127 "crash point is to be hit to trigger action");
129 static unsigned int jp_do_irq(unsigned int irq)
136 static irqreturn_t jp_handle_irq_event(unsigned int irq,
137 struct irqaction *action)
144 static void jp_tasklet_action(struct softirq_action *a)
150 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
158 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
160 struct scan_control *sc)
167 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
168 const enum hrtimer_mode mode)
175 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
183 int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
184 struct block_device *bdev, unsigned int cmd,
193 /* Return the crashpoint number or NONE if the name is invalid */
194 static enum ctype parse_cp_type(const char *what, size_t count)
198 for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
199 if (!strcmp(what, cp_type[i]))
206 static const char *cp_type_to_str(enum ctype type)
208 if (type == NONE || type < 0 || type > ARRAY_SIZE(cp_type))
211 return cp_type[type - 1];
214 static const char *cp_name_to_str(enum cname name)
216 if (name == INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
219 return cp_name[name - 1];
223 static int lkdtm_parse_commandline(void)
227 if (cpoint_count < 1 || recur_count < 1)
230 count = cpoint_count;
232 /* No special parameters */
233 if (!cpoint_type && !cpoint_name)
236 /* Neither or both of these need to be set */
237 if (!cpoint_type || !cpoint_name)
240 cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
244 for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
245 if (!strcmp(cpoint_name, cp_name[i])) {
251 /* Could not find a valid crash point */
255 static int recursive_loop(int a)
259 memset(buf,0xFF,1024);
264 return recursive_loop(a);
267 static void lkdtm_do_action(enum ctype which)
284 (void) recursive_loop(0);
286 case CORRUPT_STACK: {
287 volatile u32 data[8];
288 volatile u32 *p = data;
293 case UNALIGNED_LOAD_STORE_WRITE: {
294 static u8 data[5] __attribute__((aligned(4))) = {1, 2,
297 u32 val = 0x12345678;
299 p = (u32 *)(data + 1);
305 case OVERWRITE_ALLOCATION: {
307 u32 *data = kmalloc(len, GFP_KERNEL);
309 data[1024 / sizeof(u32)] = 0x12345678;
313 case WRITE_AFTER_FREE: {
315 u32 *data = kmalloc(len, GFP_KERNEL);
319 memset(data, 0x78, len);
329 static void lkdtm_handler(void)
332 printk(KERN_INFO "lkdtm: Crash point %s of type %s hit, trigger in %d rounds\n",
333 cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
336 lkdtm_do_action(cptype);
337 count = cpoint_count;
341 static int lkdtm_register_cpoint(enum cname which)
346 if (lkdtm.entry != NULL)
347 unregister_jprobe(&lkdtm);
351 lkdtm_do_action(cptype);
353 case INT_HARDWARE_ENTRY:
354 lkdtm.kp.symbol_name = "do_IRQ";
355 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
358 lkdtm.kp.symbol_name = "handle_IRQ_event";
359 lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
361 case INT_TASKLET_ENTRY:
362 lkdtm.kp.symbol_name = "tasklet_action";
363 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
366 lkdtm.kp.symbol_name = "ll_rw_block";
367 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
370 lkdtm.kp.symbol_name = "shrink_inactive_list";
371 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
374 lkdtm.kp.symbol_name = "hrtimer_start";
375 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
377 case SCSI_DISPATCH_CMD:
378 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
379 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
383 lkdtm.kp.symbol_name = "generic_ide_ioctl";
384 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
386 printk(KERN_INFO "lkdtm: Crash point not available\n");
391 printk(KERN_INFO "lkdtm: Invalid Crash Point\n");
396 if ((ret = register_jprobe(&lkdtm)) < 0) {
397 printk(KERN_INFO "lkdtm: Couldn't register jprobe\n");
404 static ssize_t do_register_entry(enum cname which, struct file *f,
405 const char __user *user_buf, size_t count, loff_t *off)
410 if (count >= PAGE_SIZE)
413 buf = (char *)__get_free_page(GFP_KERNEL);
416 if (copy_from_user(buf, user_buf, count)) {
417 free_page((unsigned long) buf);
420 /* NULL-terminate and remove enter */
424 cptype = parse_cp_type(buf, count);
425 free_page((unsigned long) buf);
430 err = lkdtm_register_cpoint(which);
439 /* Generic read callback that just prints out the available crash types */
440 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
441 size_t count, loff_t *off)
446 buf = (char *)__get_free_page(GFP_KERNEL);
448 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
449 for (i = 0; i < ARRAY_SIZE(cp_type); i++)
450 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
453 out = simple_read_from_buffer(user_buf, count, off,
455 free_page((unsigned long) buf);
460 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
466 static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
467 size_t count, loff_t *off)
469 return do_register_entry(INT_HARDWARE_ENTRY, f, buf, count, off);
472 static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
473 size_t count, loff_t *off)
475 return do_register_entry(INT_HW_IRQ_EN, f, buf, count, off);
478 static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
479 size_t count, loff_t *off)
481 return do_register_entry(INT_TASKLET_ENTRY, f, buf, count, off);
484 static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
485 size_t count, loff_t *off)
487 return do_register_entry(FS_DEVRW, f, buf, count, off);
490 static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
491 size_t count, loff_t *off)
493 return do_register_entry(MEM_SWAPOUT, f, buf, count, off);
496 static ssize_t timeradd_entry(struct file *f, const char __user *buf,
497 size_t count, loff_t *off)
499 return do_register_entry(TIMERADD, f, buf, count, off);
502 static ssize_t scsi_dispatch_cmd_entry(struct file *f,
503 const char __user *buf, size_t count, loff_t *off)
505 return do_register_entry(SCSI_DISPATCH_CMD, f, buf, count, off);
508 static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
509 size_t count, loff_t *off)
511 return do_register_entry(IDE_CORE_CP, f, buf, count, off);
514 /* Special entry to just crash directly. Available without KPROBEs */
515 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
516 size_t count, loff_t *off)
521 if (count >= PAGE_SIZE)
526 buf = (char *)__get_free_page(GFP_KERNEL);
529 if (copy_from_user(buf, user_buf, count)) {
530 free_page((unsigned long) buf);
533 /* NULL-terminate and remove enter */
537 type = parse_cp_type(buf, count);
538 free_page((unsigned long) buf);
542 printk(KERN_INFO "lkdtm: Performing direct entry %s\n",
543 cp_type_to_str(type));
544 lkdtm_do_action(type);
552 const struct file_operations fops;
555 static const struct crash_entry crash_entries[] = {
556 {"DIRECT", {.read = lkdtm_debugfs_read,
557 .open = lkdtm_debugfs_open,
558 .write = direct_entry} },
559 {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
560 .open = lkdtm_debugfs_open,
561 .write = int_hardware_entry} },
562 {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
563 .open = lkdtm_debugfs_open,
564 .write = int_hw_irq_en} },
565 {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
566 .open = lkdtm_debugfs_open,
567 .write = int_tasklet_entry} },
568 {"FS_DEVRW", {.read = lkdtm_debugfs_read,
569 .open = lkdtm_debugfs_open,
570 .write = fs_devrw_entry} },
571 {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
572 .open = lkdtm_debugfs_open,
573 .write = mem_swapout_entry} },
574 {"TIMERADD", {.read = lkdtm_debugfs_read,
575 .open = lkdtm_debugfs_open,
576 .write = timeradd_entry} },
577 {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
578 .open = lkdtm_debugfs_open,
579 .write = scsi_dispatch_cmd_entry} },
580 {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
581 .open = lkdtm_debugfs_open,
582 .write = ide_core_cp_entry} },
585 static struct dentry *lkdtm_debugfs_root;
587 static int __init lkdtm_module_init(void)
590 int n_debugfs_entries = 1; /* Assume only the direct entry */
593 /* Register debugfs interface */
594 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
595 if (!lkdtm_debugfs_root) {
596 printk(KERN_ERR "lkdtm: creating root dir failed\n");
600 #ifdef CONFIG_KPROBES
601 n_debugfs_entries = ARRAY_SIZE(crash_entries);
604 for (i = 0; i < n_debugfs_entries; i++) {
605 const struct crash_entry *cur = &crash_entries[i];
608 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
611 printk(KERN_ERR "lkdtm: could not create %s\n",
617 if (lkdtm_parse_commandline() == -EINVAL) {
618 printk(KERN_INFO "lkdtm: Invalid command\n");
622 if (cpoint != INVALID && cptype != NONE) {
623 ret = lkdtm_register_cpoint(cpoint);
625 printk(KERN_INFO "lkdtm: Invalid crash point %d\n",
629 printk(KERN_INFO "lkdtm: Crash point %s of type %s registered\n",
630 cpoint_name, cpoint_type);
632 printk(KERN_INFO "lkdtm: No crash points registered, enable through debugfs\n");
638 debugfs_remove_recursive(lkdtm_debugfs_root);
642 static void __exit lkdtm_module_exit(void)
644 debugfs_remove_recursive(lkdtm_debugfs_root);
646 unregister_jprobe(&lkdtm);
647 printk(KERN_INFO "lkdtm: Crash point unregistered\n");
650 module_init(lkdtm_module_init);
651 module_exit(lkdtm_module_exit);
653 MODULE_LICENSE("GPL");