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
56 CN_INT_HARDWARE_ENTRY,
75 CT_UNALIGNED_LOAD_STORE_WRITE,
76 CT_OVERWRITE_ALLOCATION,
83 static char* cp_name[] = {
95 static char* cp_type[] = {
102 "UNALIGNED_LOAD_STORE_WRITE",
103 "OVERWRITE_ALLOCATION",
110 static struct jprobe lkdtm;
112 static int lkdtm_parse_commandline(void);
113 static void lkdtm_handler(void);
115 static char* cpoint_name;
116 static char* cpoint_type;
117 static int cpoint_count = DEFAULT_COUNT;
118 static int recur_count = REC_NUM_DEFAULT;
120 static enum cname cpoint = CN_INVALID;
121 static enum ctype cptype = CT_NONE;
122 static int count = DEFAULT_COUNT;
123 static DEFINE_SPINLOCK(count_lock);
125 module_param(recur_count, int, 0644);
126 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
128 module_param(cpoint_name, charp, 0444);
129 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
130 module_param(cpoint_type, charp, 0444);
131 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
132 "hitting the crash point");
133 module_param(cpoint_count, int, 0644);
134 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
135 "crash point is to be hit to trigger action");
137 static unsigned int jp_do_irq(unsigned int irq)
144 static irqreturn_t jp_handle_irq_event(unsigned int irq,
145 struct irqaction *action)
152 static void jp_tasklet_action(struct softirq_action *a)
158 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
166 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
168 struct scan_control *sc)
175 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
176 const enum hrtimer_mode mode)
183 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
191 int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
192 struct block_device *bdev, unsigned int cmd,
201 /* Return the crashpoint number or NONE if the name is invalid */
202 static enum ctype parse_cp_type(const char *what, size_t count)
206 for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
207 if (!strcmp(what, cp_type[i]))
214 static const char *cp_type_to_str(enum ctype type)
216 if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
219 return cp_type[type - 1];
222 static const char *cp_name_to_str(enum cname name)
224 if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
227 return cp_name[name - 1];
231 static int lkdtm_parse_commandline(void)
236 if (cpoint_count < 1 || recur_count < 1)
239 spin_lock_irqsave(&count_lock, flags);
240 count = cpoint_count;
241 spin_unlock_irqrestore(&count_lock, flags);
243 /* No special parameters */
244 if (!cpoint_type && !cpoint_name)
247 /* Neither or both of these need to be set */
248 if (!cpoint_type || !cpoint_name)
251 cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
252 if (cptype == CT_NONE)
255 for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
256 if (!strcmp(cpoint_name, cp_name[i])) {
262 /* Could not find a valid crash point */
266 static int recursive_loop(int a)
270 memset(buf,0xFF,1024);
275 return recursive_loop(a);
278 static void lkdtm_do_action(enum ctype which)
295 (void) recursive_loop(0);
297 case CT_CORRUPT_STACK: {
298 volatile u32 data[8];
299 volatile u32 *p = data;
304 case CT_UNALIGNED_LOAD_STORE_WRITE: {
305 static u8 data[5] __attribute__((aligned(4))) = {1, 2,
308 u32 val = 0x12345678;
310 p = (u32 *)(data + 1);
316 case CT_OVERWRITE_ALLOCATION: {
318 u32 *data = kmalloc(len, GFP_KERNEL);
320 data[1024 / sizeof(u32)] = 0x12345678;
324 case CT_WRITE_AFTER_FREE: {
326 u32 *data = kmalloc(len, GFP_KERNEL);
330 memset(data, 0x78, len);
344 set_current_state(TASK_UNINTERRUPTIBLE);
354 static void lkdtm_handler(void)
359 spin_lock_irqsave(&count_lock, flags);
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);
366 count = cpoint_count;
368 spin_unlock_irqrestore(&count_lock, flags);
371 lkdtm_do_action(cptype);
374 static int lkdtm_register_cpoint(enum cname which)
379 if (lkdtm.entry != NULL)
380 unregister_jprobe(&lkdtm);
384 lkdtm_do_action(cptype);
386 case CN_INT_HARDWARE_ENTRY:
387 lkdtm.kp.symbol_name = "do_IRQ";
388 lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
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;
394 case CN_INT_TASKLET_ENTRY:
395 lkdtm.kp.symbol_name = "tasklet_action";
396 lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
399 lkdtm.kp.symbol_name = "ll_rw_block";
400 lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
403 lkdtm.kp.symbol_name = "shrink_inactive_list";
404 lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
407 lkdtm.kp.symbol_name = "hrtimer_start";
408 lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
410 case CN_SCSI_DISPATCH_CMD:
411 lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
412 lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
416 lkdtm.kp.symbol_name = "generic_ide_ioctl";
417 lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
419 printk(KERN_INFO "lkdtm: Crash point not available\n");
424 printk(KERN_INFO "lkdtm: Invalid Crash Point\n");
429 if ((ret = register_jprobe(&lkdtm)) < 0) {
430 printk(KERN_INFO "lkdtm: Couldn't register jprobe\n");
437 static ssize_t do_register_entry(enum cname which, struct file *f,
438 const char __user *user_buf, size_t count, loff_t *off)
443 if (count >= PAGE_SIZE)
446 buf = (char *)__get_free_page(GFP_KERNEL);
449 if (copy_from_user(buf, user_buf, count)) {
450 free_page((unsigned long) buf);
453 /* NULL-terminate and remove enter */
457 cptype = parse_cp_type(buf, count);
458 free_page((unsigned long) buf);
460 if (cptype == CT_NONE)
463 err = lkdtm_register_cpoint(which);
472 /* Generic read callback that just prints out the available crash types */
473 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
474 size_t count, loff_t *off)
479 buf = (char *)__get_free_page(GFP_KERNEL);
481 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
482 for (i = 0; i < ARRAY_SIZE(cp_type); i++)
483 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
486 out = simple_read_from_buffer(user_buf, count, off,
488 free_page((unsigned long) buf);
493 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
499 static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
500 size_t count, loff_t *off)
502 return do_register_entry(CN_INT_HARDWARE_ENTRY, f, buf, count, off);
505 static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
506 size_t count, loff_t *off)
508 return do_register_entry(CN_INT_HW_IRQ_EN, f, buf, count, off);
511 static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
512 size_t count, loff_t *off)
514 return do_register_entry(CN_INT_TASKLET_ENTRY, f, buf, count, off);
517 static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
518 size_t count, loff_t *off)
520 return do_register_entry(CN_FS_DEVRW, f, buf, count, off);
523 static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
524 size_t count, loff_t *off)
526 return do_register_entry(CN_MEM_SWAPOUT, f, buf, count, off);
529 static ssize_t timeradd_entry(struct file *f, const char __user *buf,
530 size_t count, loff_t *off)
532 return do_register_entry(CN_TIMERADD, f, buf, count, off);
535 static ssize_t scsi_dispatch_cmd_entry(struct file *f,
536 const char __user *buf, size_t count, loff_t *off)
538 return do_register_entry(CN_SCSI_DISPATCH_CMD, f, buf, count, off);
541 static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
542 size_t count, loff_t *off)
544 return do_register_entry(CN_IDE_CORE_CP, f, buf, count, off);
547 /* Special entry to just crash directly. Available without KPROBEs */
548 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
549 size_t count, loff_t *off)
554 if (count >= PAGE_SIZE)
559 buf = (char *)__get_free_page(GFP_KERNEL);
562 if (copy_from_user(buf, user_buf, count)) {
563 free_page((unsigned long) buf);
566 /* NULL-terminate and remove enter */
570 type = parse_cp_type(buf, count);
571 free_page((unsigned long) buf);
575 printk(KERN_INFO "lkdtm: Performing direct entry %s\n",
576 cp_type_to_str(type));
577 lkdtm_do_action(type);
585 const struct file_operations fops;
588 static const struct crash_entry crash_entries[] = {
589 {"DIRECT", {.read = lkdtm_debugfs_read,
590 .llseek = generic_file_llseek,
591 .open = lkdtm_debugfs_open,
592 .write = direct_entry} },
593 {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
594 .llseek = generic_file_llseek,
595 .open = lkdtm_debugfs_open,
596 .write = int_hardware_entry} },
597 {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
598 .llseek = generic_file_llseek,
599 .open = lkdtm_debugfs_open,
600 .write = int_hw_irq_en} },
601 {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
602 .llseek = generic_file_llseek,
603 .open = lkdtm_debugfs_open,
604 .write = int_tasklet_entry} },
605 {"FS_DEVRW", {.read = lkdtm_debugfs_read,
606 .llseek = generic_file_llseek,
607 .open = lkdtm_debugfs_open,
608 .write = fs_devrw_entry} },
609 {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
610 .llseek = generic_file_llseek,
611 .open = lkdtm_debugfs_open,
612 .write = mem_swapout_entry} },
613 {"TIMERADD", {.read = lkdtm_debugfs_read,
614 .llseek = generic_file_llseek,
615 .open = lkdtm_debugfs_open,
616 .write = timeradd_entry} },
617 {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
618 .llseek = generic_file_llseek,
619 .open = lkdtm_debugfs_open,
620 .write = scsi_dispatch_cmd_entry} },
621 {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
622 .llseek = generic_file_llseek,
623 .open = lkdtm_debugfs_open,
624 .write = ide_core_cp_entry} },
627 static struct dentry *lkdtm_debugfs_root;
629 static int __init lkdtm_module_init(void)
632 int n_debugfs_entries = 1; /* Assume only the direct entry */
635 /* Register debugfs interface */
636 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
637 if (!lkdtm_debugfs_root) {
638 printk(KERN_ERR "lkdtm: creating root dir failed\n");
642 #ifdef CONFIG_KPROBES
643 n_debugfs_entries = ARRAY_SIZE(crash_entries);
646 for (i = 0; i < n_debugfs_entries; i++) {
647 const struct crash_entry *cur = &crash_entries[i];
650 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
653 printk(KERN_ERR "lkdtm: could not create %s\n",
659 if (lkdtm_parse_commandline() == -EINVAL) {
660 printk(KERN_INFO "lkdtm: Invalid command\n");
664 if (cpoint != CN_INVALID && cptype != CT_NONE) {
665 ret = lkdtm_register_cpoint(cpoint);
667 printk(KERN_INFO "lkdtm: Invalid crash point %d\n",
671 printk(KERN_INFO "lkdtm: Crash point %s of type %s registered\n",
672 cpoint_name, cpoint_type);
674 printk(KERN_INFO "lkdtm: No crash points registered, enable through debugfs\n");
680 debugfs_remove_recursive(lkdtm_debugfs_root);
684 static void __exit lkdtm_module_exit(void)
686 debugfs_remove_recursive(lkdtm_debugfs_root);
688 unregister_jprobe(&lkdtm);
689 printk(KERN_INFO "lkdtm: Crash point unregistered\n");
692 module_init(lkdtm_module_init);
693 module_exit(lkdtm_module_exit);
695 MODULE_LICENSE("GPL");