2 * Linux Kernel Dump Test Module for testing kernel crashes conditions:
3 * induces system failures at predefined crashpoints and under predefined
4 * operational conditions in order to evaluate the reliability of kernel
5 * sanity checking and crash dumps obtained using different dumping
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 * Copyright (C) IBM Corporation, 2006
24 * Author: Ankita Garg <ankita@in.ibm.com>
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
35 #include <linux/module.h>
36 #include <linux/buffer_head.h>
37 #include <linux/kprobes.h>
38 #include <linux/list.h>
39 #include <linux/init.h>
40 #include <linux/interrupt.h>
41 #include <linux/hrtimer.h>
42 #include <linux/slab.h>
43 #include <scsi/scsi_cmnd.h>
44 #include <linux/debugfs.h>
47 #include <linux/ide.h>
50 #define DEFAULT_COUNT 10
52 static int lkdtm_debugfs_open(struct inode *inode, struct file *file);
53 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
54 size_t count, loff_t *off);
55 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
56 size_t count, loff_t *off);
59 static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs);
60 static ssize_t lkdtm_debugfs_entry(struct file *f,
61 const char __user *user_buf,
62 size_t count, loff_t *off);
63 # define CRASHPOINT_KPROBE(_symbol) \
65 .symbol_name = (_symbol), \
66 .pre_handler = lkdtm_kprobe_handler, \
68 # define CRASHPOINT_WRITE(_symbol) \
69 (_symbol) ? lkdtm_debugfs_entry : direct_entry
71 # define CRASHPOINT_KPROBE(_symbol)
72 # define CRASHPOINT_WRITE(_symbol) direct_entry
78 const struct file_operations fops;
82 #define CRASHPOINT(_name, _symbol) \
86 .read = lkdtm_debugfs_read, \
87 .llseek = generic_file_llseek, \
88 .open = lkdtm_debugfs_open, \
89 .write = CRASHPOINT_WRITE(_symbol) \
91 CRASHPOINT_KPROBE(_symbol) \
94 /* Define the possible places where we can trigger a crash point. */
95 static struct crashpoint crashpoints[] = {
96 CRASHPOINT("DIRECT", NULL),
98 CRASHPOINT("INT_HARDWARE_ENTRY", "do_IRQ"),
99 CRASHPOINT("INT_HW_IRQ_EN", "handle_IRQ_event"),
100 CRASHPOINT("INT_TASKLET_ENTRY", "tasklet_action"),
101 CRASHPOINT("FS_DEVRW", "ll_rw_block"),
102 CRASHPOINT("MEM_SWAPOUT", "shrink_inactive_list"),
103 CRASHPOINT("TIMERADD", "hrtimer_start"),
104 CRASHPOINT("SCSI_DISPATCH_CMD", "scsi_dispatch_cmd"),
106 CRASHPOINT("IDE_CORE_CP", "generic_ide_ioctl"),
118 #define CRASHTYPE(_name) \
120 .name = __stringify(_name), \
121 .func = lkdtm_ ## _name, \
124 /* Define the possible types of crashes that can be triggered. */
125 static const struct crashtype crashtypes[] = {
129 CRASHTYPE(EXCEPTION),
132 CRASHTYPE(CORRUPT_LIST_ADD),
133 CRASHTYPE(CORRUPT_LIST_DEL),
134 CRASHTYPE(CORRUPT_USER_DS),
135 CRASHTYPE(CORRUPT_STACK),
136 CRASHTYPE(CORRUPT_STACK_STRONG),
137 CRASHTYPE(STACK_GUARD_PAGE_LEADING),
138 CRASHTYPE(STACK_GUARD_PAGE_TRAILING),
139 CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
140 CRASHTYPE(OVERWRITE_ALLOCATION),
141 CRASHTYPE(WRITE_AFTER_FREE),
142 CRASHTYPE(READ_AFTER_FREE),
143 CRASHTYPE(WRITE_BUDDY_AFTER_FREE),
144 CRASHTYPE(READ_BUDDY_AFTER_FREE),
145 CRASHTYPE(SOFTLOCKUP),
146 CRASHTYPE(HARDLOCKUP),
147 CRASHTYPE(SPINLOCKUP),
148 CRASHTYPE(HUNG_TASK),
149 CRASHTYPE(EXEC_DATA),
150 CRASHTYPE(EXEC_STACK),
151 CRASHTYPE(EXEC_KMALLOC),
152 CRASHTYPE(EXEC_VMALLOC),
153 CRASHTYPE(EXEC_RODATA),
154 CRASHTYPE(EXEC_USERSPACE),
155 CRASHTYPE(ACCESS_USERSPACE),
157 CRASHTYPE(WRITE_RO_AFTER_INIT),
158 CRASHTYPE(WRITE_KERN),
159 CRASHTYPE(REFCOUNT_INC_OVERFLOW),
160 CRASHTYPE(REFCOUNT_ADD_OVERFLOW),
161 CRASHTYPE(REFCOUNT_INC_NOT_ZERO_OVERFLOW),
162 CRASHTYPE(REFCOUNT_ADD_NOT_ZERO_OVERFLOW),
163 CRASHTYPE(REFCOUNT_DEC_ZERO),
164 CRASHTYPE(REFCOUNT_DEC_NEGATIVE),
165 CRASHTYPE(REFCOUNT_DEC_AND_TEST_NEGATIVE),
166 CRASHTYPE(REFCOUNT_SUB_AND_TEST_NEGATIVE),
167 CRASHTYPE(REFCOUNT_INC_ZERO),
168 CRASHTYPE(REFCOUNT_ADD_ZERO),
169 CRASHTYPE(REFCOUNT_INC_SATURATED),
170 CRASHTYPE(REFCOUNT_DEC_SATURATED),
171 CRASHTYPE(REFCOUNT_ADD_SATURATED),
172 CRASHTYPE(REFCOUNT_INC_NOT_ZERO_SATURATED),
173 CRASHTYPE(REFCOUNT_ADD_NOT_ZERO_SATURATED),
174 CRASHTYPE(REFCOUNT_DEC_AND_TEST_SATURATED),
175 CRASHTYPE(REFCOUNT_SUB_AND_TEST_SATURATED),
176 CRASHTYPE(REFCOUNT_TIMING),
177 CRASHTYPE(ATOMIC_TIMING),
178 CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
179 CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
180 CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
181 CRASHTYPE(USERCOPY_HEAP_FLAG_FROM),
182 CRASHTYPE(USERCOPY_STACK_FRAME_TO),
183 CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
184 CRASHTYPE(USERCOPY_STACK_BEYOND),
185 CRASHTYPE(USERCOPY_KERNEL),
189 /* Global kprobe entry and crashtype. */
190 static struct kprobe *lkdtm_kprobe;
191 static struct crashpoint *lkdtm_crashpoint;
192 static const struct crashtype *lkdtm_crashtype;
194 /* Module parameters */
195 static int recur_count = -1;
196 module_param(recur_count, int, 0644);
197 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
199 static char* cpoint_name;
200 module_param(cpoint_name, charp, 0444);
201 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
203 static char* cpoint_type;
204 module_param(cpoint_type, charp, 0444);
205 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
206 "hitting the crash point");
208 static int cpoint_count = DEFAULT_COUNT;
209 module_param(cpoint_count, int, 0644);
210 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
211 "crash point is to be hit to trigger action");
214 /* Return the crashtype number or NULL if the name is invalid */
215 static const struct crashtype *find_crashtype(const char *name)
219 for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
220 if (!strcmp(name, crashtypes[i].name))
221 return &crashtypes[i];
228 * This is forced noinline just so it distinctly shows up in the stackdump
229 * which makes validation of expected lkdtm crashes easier.
231 static noinline void lkdtm_do_action(const struct crashtype *crashtype)
233 if (WARN_ON(!crashtype || !crashtype->func))
238 static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
239 const struct crashtype *crashtype)
243 /* If this doesn't have a symbol, just call immediately. */
244 if (!crashpoint->kprobe.symbol_name) {
245 lkdtm_do_action(crashtype);
249 if (lkdtm_kprobe != NULL)
250 unregister_kprobe(lkdtm_kprobe);
252 lkdtm_crashpoint = crashpoint;
253 lkdtm_crashtype = crashtype;
254 lkdtm_kprobe = &crashpoint->kprobe;
255 ret = register_kprobe(lkdtm_kprobe);
257 pr_info("Couldn't register kprobe %s\n",
258 crashpoint->kprobe.symbol_name);
260 lkdtm_crashpoint = NULL;
261 lkdtm_crashtype = NULL;
267 #ifdef CONFIG_KPROBES
268 /* Global crash counter and spinlock. */
269 static int crash_count = DEFAULT_COUNT;
270 static DEFINE_SPINLOCK(crash_count_lock);
272 /* Called by kprobe entry points. */
273 static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
278 if (WARN_ON(!lkdtm_crashpoint || !lkdtm_crashtype))
281 spin_lock_irqsave(&crash_count_lock, flags);
283 pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
284 lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);
286 if (crash_count == 0) {
288 crash_count = cpoint_count;
290 spin_unlock_irqrestore(&crash_count_lock, flags);
293 lkdtm_do_action(lkdtm_crashtype);
298 static ssize_t lkdtm_debugfs_entry(struct file *f,
299 const char __user *user_buf,
300 size_t count, loff_t *off)
302 struct crashpoint *crashpoint = file_inode(f)->i_private;
303 const struct crashtype *crashtype = NULL;
307 if (count >= PAGE_SIZE)
310 buf = (char *)__get_free_page(GFP_KERNEL);
313 if (copy_from_user(buf, user_buf, count)) {
314 free_page((unsigned long) buf);
317 /* NULL-terminate and remove enter */
321 crashtype = find_crashtype(buf);
322 free_page((unsigned long)buf);
327 err = lkdtm_register_cpoint(crashpoint, crashtype);
337 /* Generic read callback that just prints out the available crash types */
338 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
339 size_t count, loff_t *off)
344 buf = (char *)__get_free_page(GFP_KERNEL);
348 n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
349 for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
350 n += snprintf(buf + n, PAGE_SIZE - n, "%s\n",
355 out = simple_read_from_buffer(user_buf, count, off,
357 free_page((unsigned long) buf);
362 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
367 /* Special entry to just crash directly. Available without KPROBEs */
368 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
369 size_t count, loff_t *off)
371 const struct crashtype *crashtype;
374 if (count >= PAGE_SIZE)
379 buf = (char *)__get_free_page(GFP_KERNEL);
382 if (copy_from_user(buf, user_buf, count)) {
383 free_page((unsigned long) buf);
386 /* NULL-terminate and remove enter */
390 crashtype = find_crashtype(buf);
391 free_page((unsigned long) buf);
395 pr_info("Performing direct entry %s\n", crashtype->name);
396 lkdtm_do_action(crashtype);
402 static struct dentry *lkdtm_debugfs_root;
404 static int __init lkdtm_module_init(void)
406 struct crashpoint *crashpoint = NULL;
407 const struct crashtype *crashtype = NULL;
411 /* Neither or both of these need to be set */
412 if ((cpoint_type || cpoint_name) && !(cpoint_type && cpoint_name)) {
413 pr_err("Need both cpoint_type and cpoint_name or neither\n");
418 crashtype = find_crashtype(cpoint_type);
420 pr_err("Unknown crashtype '%s'\n", cpoint_type);
426 for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
427 if (!strcmp(cpoint_name, crashpoints[i].name))
428 crashpoint = &crashpoints[i];
431 /* Refuse unknown crashpoints. */
433 pr_err("Invalid crashpoint %s\n", cpoint_name);
438 #ifdef CONFIG_KPROBES
439 /* Set crash count. */
440 crash_count = cpoint_count;
443 /* Handle test-specific initialization. */
444 lkdtm_bugs_init(&recur_count);
446 lkdtm_usercopy_init();
448 /* Register debugfs interface */
449 lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
450 if (!lkdtm_debugfs_root) {
451 pr_err("creating root dir failed\n");
455 /* Install debugfs trigger files. */
456 for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
457 struct crashpoint *cur = &crashpoints[i];
460 de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
463 pr_err("could not create crashpoint %s\n", cur->name);
468 /* Install crashpoint if one was selected. */
470 ret = lkdtm_register_cpoint(crashpoint, crashtype);
472 pr_info("Invalid crashpoint %s\n", crashpoint->name);
475 pr_info("Crash point %s of type %s registered\n",
476 crashpoint->name, cpoint_type);
478 pr_info("No crash points registered, enable through debugfs\n");
484 debugfs_remove_recursive(lkdtm_debugfs_root);
488 static void __exit lkdtm_module_exit(void)
490 debugfs_remove_recursive(lkdtm_debugfs_root);
492 /* Handle test-specific clean-up. */
493 lkdtm_usercopy_exit();
495 if (lkdtm_kprobe != NULL)
496 unregister_kprobe(lkdtm_kprobe);
498 pr_info("Crash point unregistered\n");
501 module_init(lkdtm_module_init);
502 module_exit(lkdtm_module_exit);
504 MODULE_LICENSE("GPL");
505 MODULE_DESCRIPTION("Kernel crash testing module");