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
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 #include <linux/kernel.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>
52 #include <linux/ide.h>
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)
63 #define REC_STACK_SIZE (THREAD_SIZE / 8)
65 #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
67 #define DEFAULT_COUNT 10
72 CN_INT_HARDWARE_ENTRY
,
92 CT_UNALIGNED_LOAD_STORE_WRITE
,
93 CT_OVERWRITE_ALLOCATION
,
96 CT_WRITE_BUDDY_AFTER_FREE
,
97 CT_READ_BUDDY_AFTER_FREE
,
109 CT_WRITE_RO_AFTER_INIT
,
114 static char* cp_name
[] = {
115 "INT_HARDWARE_ENTRY",
126 static char* cp_type
[] = {
134 "UNALIGNED_LOAD_STORE_WRITE",
135 "OVERWRITE_ALLOCATION",
138 "WRITE_BUDDY_AFTER_FREE",
139 "READ_BUDDY_AFTER_FREE",
151 "WRITE_RO_AFTER_INIT",
156 static struct jprobe lkdtm
;
158 static int lkdtm_parse_commandline(void);
159 static void lkdtm_handler(void);
161 static char* cpoint_name
;
162 static char* cpoint_type
;
163 static int cpoint_count
= DEFAULT_COUNT
;
164 static int recur_count
= REC_NUM_DEFAULT
;
166 static enum cname cpoint
= CN_INVALID
;
167 static enum ctype cptype
= CT_NONE
;
168 static int count
= DEFAULT_COUNT
;
169 static DEFINE_SPINLOCK(count_lock
);
170 static DEFINE_SPINLOCK(lock_me_up
);
172 static u8 data_area
[EXEC_SIZE
];
174 static const unsigned long rodata
= 0xAA55AA55;
175 static unsigned long ro_after_init __ro_after_init
= 0x55AA5500;
177 module_param(recur_count
, int, 0644);
178 MODULE_PARM_DESC(recur_count
, " Recursion level for the stack overflow test");
179 module_param(cpoint_name
, charp
, 0444);
180 MODULE_PARM_DESC(cpoint_name
, " Crash Point, where kernel is to be crashed");
181 module_param(cpoint_type
, charp
, 0444);
182 MODULE_PARM_DESC(cpoint_type
, " Crash Point Type, action to be taken on "\
183 "hitting the crash point");
184 module_param(cpoint_count
, int, 0644);
185 MODULE_PARM_DESC(cpoint_count
, " Crash Point Count, number of times the "\
186 "crash point is to be hit to trigger action");
188 static unsigned int jp_do_irq(unsigned int irq
)
195 static irqreturn_t
jp_handle_irq_event(unsigned int irq
,
196 struct irqaction
*action
)
203 static void jp_tasklet_action(struct softirq_action
*a
)
209 static void jp_ll_rw_block(int rw
, int nr
, struct buffer_head
*bhs
[])
217 static unsigned long jp_shrink_inactive_list(unsigned long max_scan
,
219 struct scan_control
*sc
)
226 static int jp_hrtimer_start(struct hrtimer
*timer
, ktime_t tim
,
227 const enum hrtimer_mode mode
)
234 static int jp_scsi_dispatch_cmd(struct scsi_cmnd
*cmd
)
242 static int jp_generic_ide_ioctl(ide_drive_t
*drive
, struct file
*file
,
243 struct block_device
*bdev
, unsigned int cmd
,
252 /* Return the crashpoint number or NONE if the name is invalid */
253 static enum ctype
parse_cp_type(const char *what
, size_t count
)
257 for (i
= 0; i
< ARRAY_SIZE(cp_type
); i
++) {
258 if (!strcmp(what
, cp_type
[i
]))
265 static const char *cp_type_to_str(enum ctype type
)
267 if (type
== CT_NONE
|| type
< 0 || type
> ARRAY_SIZE(cp_type
))
270 return cp_type
[type
- 1];
273 static const char *cp_name_to_str(enum cname name
)
275 if (name
== CN_INVALID
|| name
< 0 || name
> ARRAY_SIZE(cp_name
))
278 return cp_name
[name
- 1];
282 static int lkdtm_parse_commandline(void)
287 if (cpoint_count
< 1 || recur_count
< 1)
290 spin_lock_irqsave(&count_lock
, flags
);
291 count
= cpoint_count
;
292 spin_unlock_irqrestore(&count_lock
, flags
);
294 /* No special parameters */
295 if (!cpoint_type
&& !cpoint_name
)
298 /* Neither or both of these need to be set */
299 if (!cpoint_type
|| !cpoint_name
)
302 cptype
= parse_cp_type(cpoint_type
, strlen(cpoint_type
));
303 if (cptype
== CT_NONE
)
306 for (i
= 0; i
< ARRAY_SIZE(cp_name
); i
++) {
307 if (!strcmp(cpoint_name
, cp_name
[i
])) {
313 /* Could not find a valid crash point */
317 static int recursive_loop(int remaining
)
319 char buf
[REC_STACK_SIZE
];
321 /* Make sure compiler does not optimize this away. */
322 memset(buf
, (remaining
& 0xff) | 0x1, REC_STACK_SIZE
);
326 return recursive_loop(remaining
- 1);
329 static void do_nothing(void)
334 /* Must immediately follow do_nothing for size calculuations to work out. */
335 static void do_overwritten(void)
337 pr_info("do_overwritten wasn't overwritten!\n");
341 static noinline
void corrupt_stack(void)
343 /* Use default char array length that triggers stack protection. */
346 memset((void *)data
, 0, 64);
349 static void noinline
execute_location(void *dst
)
351 void (*func
)(void) = dst
;
353 pr_info("attempting ok execution at %p\n", do_nothing
);
356 memcpy(dst
, do_nothing
, EXEC_SIZE
);
357 flush_icache_range((unsigned long)dst
, (unsigned long)dst
+ EXEC_SIZE
);
358 pr_info("attempting bad execution at %p\n", func
);
362 static void execute_user_location(void *dst
)
364 /* Intentionally crossing kernel/user memory boundary. */
365 void (*func
)(void) = dst
;
367 pr_info("attempting ok execution at %p\n", do_nothing
);
370 if (copy_to_user((void __user
*)dst
, do_nothing
, EXEC_SIZE
))
372 flush_icache_range((unsigned long)dst
, (unsigned long)dst
+ EXEC_SIZE
);
373 pr_info("attempting bad execution at %p\n", func
);
377 static void lkdtm_do_action(enum ctype which
)
397 (void) recursive_loop(recur_count
);
399 case CT_CORRUPT_STACK
:
402 case CT_UNALIGNED_LOAD_STORE_WRITE
: {
403 static u8 data
[5] __attribute__((aligned(4))) = {1, 2,
406 u32 val
= 0x12345678;
408 p
= (u32
*)(data
+ 1);
414 case CT_OVERWRITE_ALLOCATION
: {
416 u32
*data
= kmalloc(len
, GFP_KERNEL
);
418 data
[1024 / sizeof(u32
)] = 0x12345678;
422 case CT_WRITE_AFTER_FREE
: {
426 * The slub allocator uses the first word to store the free
427 * pointer in some configurations. Use the middle of the
428 * allocation to avoid running into the freelist
430 size_t offset
= (len
/ sizeof(*base
)) / 2;
432 base
= kmalloc(len
, GFP_KERNEL
);
433 pr_info("Allocated memory %p-%p\n", base
, &base
[offset
* 2]);
434 pr_info("Attempting bad write to freed memory at %p\n",
437 base
[offset
] = 0x0abcdef0;
438 /* Attempt to notice the overwrite. */
439 again
= kmalloc(len
, GFP_KERNEL
);
442 pr_info("Hmm, didn't get the same memory range.\n");
446 case CT_READ_AFTER_FREE
: {
447 int *base
, *val
, saw
;
450 * The slub allocator uses the first word to store the free
451 * pointer in some configurations. Use the middle of the
452 * allocation to avoid running into the freelist
454 size_t offset
= (len
/ sizeof(*base
)) / 2;
456 base
= kmalloc(len
, GFP_KERNEL
);
460 val
= kmalloc(len
, GFP_KERNEL
);
466 pr_info("Value in memory before free: %x\n", base
[offset
]);
470 pr_info("Attempting bad read from freed memory\n");
473 /* Good! Poisoning happened, so declare a win. */
474 pr_info("Memory correctly poisoned (%x)\n", saw
);
477 pr_info("Memory was not poisoned\n");
482 case CT_WRITE_BUDDY_AFTER_FREE
: {
483 unsigned long p
= __get_free_page(GFP_KERNEL
);
486 pr_info("Writing to the buddy page before free\n");
487 memset((void *)p
, 0x3, PAGE_SIZE
);
490 pr_info("Attempting bad write to the buddy page after free\n");
491 memset((void *)p
, 0x78, PAGE_SIZE
);
492 /* Attempt to notice the overwrite. */
493 p
= __get_free_page(GFP_KERNEL
);
499 case CT_READ_BUDDY_AFTER_FREE
: {
500 unsigned long p
= __get_free_page(GFP_KERNEL
);
501 int saw
, *val
= kmalloc(1024, GFP_KERNEL
);
514 pr_info("Value in memory before free: %x\n", base
[0]);
516 pr_info("Attempting to read from freed memory\n");
519 /* Good! Poisoning happened, so declare a win. */
520 pr_info("Memory correctly poisoned (%x)\n", saw
);
523 pr_info("Buddy page was not poisoned\n");
539 /* Must be called twice to trigger. */
540 spin_lock(&lock_me_up
);
541 /* Let sparse know we intended to exit holding the lock. */
542 __release(&lock_me_up
);
545 set_current_state(TASK_UNINTERRUPTIBLE
);
549 execute_location(data_area
);
551 case CT_EXEC_STACK
: {
552 u8 stack_area
[EXEC_SIZE
];
553 execute_location(stack_area
);
556 case CT_EXEC_KMALLOC
: {
557 u32
*kmalloc_area
= kmalloc(EXEC_SIZE
, GFP_KERNEL
);
558 execute_location(kmalloc_area
);
562 case CT_EXEC_VMALLOC
: {
563 u32
*vmalloc_area
= vmalloc(EXEC_SIZE
);
564 execute_location(vmalloc_area
);
568 case CT_EXEC_USERSPACE
: {
569 unsigned long user_addr
;
571 user_addr
= vm_mmap(NULL
, 0, PAGE_SIZE
,
572 PROT_READ
| PROT_WRITE
| PROT_EXEC
,
573 MAP_ANONYMOUS
| MAP_PRIVATE
, 0);
574 if (user_addr
>= TASK_SIZE
) {
575 pr_warn("Failed to allocate user memory\n");
578 execute_user_location((void *)user_addr
);
579 vm_munmap(user_addr
, PAGE_SIZE
);
582 case CT_ACCESS_USERSPACE
: {
583 unsigned long user_addr
, tmp
= 0;
586 user_addr
= vm_mmap(NULL
, 0, PAGE_SIZE
,
587 PROT_READ
| PROT_WRITE
| PROT_EXEC
,
588 MAP_ANONYMOUS
| MAP_PRIVATE
, 0);
589 if (user_addr
>= TASK_SIZE
) {
590 pr_warn("Failed to allocate user memory\n");
594 if (copy_to_user((void __user
*)user_addr
, &tmp
, sizeof(tmp
))) {
595 pr_warn("copy_to_user failed\n");
596 vm_munmap(user_addr
, PAGE_SIZE
);
600 ptr
= (unsigned long *)user_addr
;
602 pr_info("attempting bad read at %p\n", ptr
);
606 pr_info("attempting bad write at %p\n", ptr
);
609 vm_munmap(user_addr
, PAGE_SIZE
);
614 /* Explicitly cast away "const" for the test. */
615 unsigned long *ptr
= (unsigned long *)&rodata
;
617 pr_info("attempting bad rodata write at %p\n", ptr
);
622 case CT_WRITE_RO_AFTER_INIT
: {
623 unsigned long *ptr
= &ro_after_init
;
626 * Verify we were written to during init. Since an Oops
627 * is considered a "success", a failure is to just skip the
630 if ((*ptr
& 0xAA) != 0xAA) {
631 pr_info("%p was NOT written during init!?\n", ptr
);
635 pr_info("attempting bad ro_after_init write at %p\n", ptr
);
640 case CT_WRITE_KERN
: {
644 size
= (unsigned long)do_overwritten
-
645 (unsigned long)do_nothing
;
646 ptr
= (unsigned char *)do_overwritten
;
648 pr_info("attempting bad %zu byte write at %p\n", size
, ptr
);
649 memcpy(ptr
, (unsigned char *)do_nothing
, size
);
650 flush_icache_range((unsigned long)ptr
,
651 (unsigned long)(ptr
+ size
));
656 case CT_WRAP_ATOMIC
: {
657 atomic_t under
= ATOMIC_INIT(INT_MIN
);
658 atomic_t over
= ATOMIC_INIT(INT_MAX
);
660 pr_info("attempting atomic underflow\n");
662 pr_info("attempting atomic overflow\n");
674 static void lkdtm_handler(void)
679 spin_lock_irqsave(&count_lock
, flags
);
681 pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
682 cp_name_to_str(cpoint
), cp_type_to_str(cptype
), count
);
686 count
= cpoint_count
;
688 spin_unlock_irqrestore(&count_lock
, flags
);
691 lkdtm_do_action(cptype
);
694 static int lkdtm_register_cpoint(enum cname which
)
699 if (lkdtm
.entry
!= NULL
)
700 unregister_jprobe(&lkdtm
);
704 lkdtm_do_action(cptype
);
706 case CN_INT_HARDWARE_ENTRY
:
707 lkdtm
.kp
.symbol_name
= "do_IRQ";
708 lkdtm
.entry
= (kprobe_opcode_t
*) jp_do_irq
;
710 case CN_INT_HW_IRQ_EN
:
711 lkdtm
.kp
.symbol_name
= "handle_IRQ_event";
712 lkdtm
.entry
= (kprobe_opcode_t
*) jp_handle_irq_event
;
714 case CN_INT_TASKLET_ENTRY
:
715 lkdtm
.kp
.symbol_name
= "tasklet_action";
716 lkdtm
.entry
= (kprobe_opcode_t
*) jp_tasklet_action
;
719 lkdtm
.kp
.symbol_name
= "ll_rw_block";
720 lkdtm
.entry
= (kprobe_opcode_t
*) jp_ll_rw_block
;
723 lkdtm
.kp
.symbol_name
= "shrink_inactive_list";
724 lkdtm
.entry
= (kprobe_opcode_t
*) jp_shrink_inactive_list
;
727 lkdtm
.kp
.symbol_name
= "hrtimer_start";
728 lkdtm
.entry
= (kprobe_opcode_t
*) jp_hrtimer_start
;
730 case CN_SCSI_DISPATCH_CMD
:
731 lkdtm
.kp
.symbol_name
= "scsi_dispatch_cmd";
732 lkdtm
.entry
= (kprobe_opcode_t
*) jp_scsi_dispatch_cmd
;
736 lkdtm
.kp
.symbol_name
= "generic_ide_ioctl";
737 lkdtm
.entry
= (kprobe_opcode_t
*) jp_generic_ide_ioctl
;
739 pr_info("Crash point not available\n");
744 pr_info("Invalid Crash Point\n");
749 if ((ret
= register_jprobe(&lkdtm
)) < 0) {
750 pr_info("Couldn't register jprobe\n");
757 static ssize_t
do_register_entry(enum cname which
, struct file
*f
,
758 const char __user
*user_buf
, size_t count
, loff_t
*off
)
763 if (count
>= PAGE_SIZE
)
766 buf
= (char *)__get_free_page(GFP_KERNEL
);
769 if (copy_from_user(buf
, user_buf
, count
)) {
770 free_page((unsigned long) buf
);
773 /* NULL-terminate and remove enter */
777 cptype
= parse_cp_type(buf
, count
);
778 free_page((unsigned long) buf
);
780 if (cptype
== CT_NONE
)
783 err
= lkdtm_register_cpoint(which
);
792 /* Generic read callback that just prints out the available crash types */
793 static ssize_t
lkdtm_debugfs_read(struct file
*f
, char __user
*user_buf
,
794 size_t count
, loff_t
*off
)
799 buf
= (char *)__get_free_page(GFP_KERNEL
);
803 n
= snprintf(buf
, PAGE_SIZE
, "Available crash types:\n");
804 for (i
= 0; i
< ARRAY_SIZE(cp_type
); i
++)
805 n
+= snprintf(buf
+ n
, PAGE_SIZE
- n
, "%s\n", cp_type
[i
]);
808 out
= simple_read_from_buffer(user_buf
, count
, off
,
810 free_page((unsigned long) buf
);
815 static int lkdtm_debugfs_open(struct inode
*inode
, struct file
*file
)
821 static ssize_t
int_hardware_entry(struct file
*f
, const char __user
*buf
,
822 size_t count
, loff_t
*off
)
824 return do_register_entry(CN_INT_HARDWARE_ENTRY
, f
, buf
, count
, off
);
827 static ssize_t
int_hw_irq_en(struct file
*f
, const char __user
*buf
,
828 size_t count
, loff_t
*off
)
830 return do_register_entry(CN_INT_HW_IRQ_EN
, f
, buf
, count
, off
);
833 static ssize_t
int_tasklet_entry(struct file
*f
, const char __user
*buf
,
834 size_t count
, loff_t
*off
)
836 return do_register_entry(CN_INT_TASKLET_ENTRY
, f
, buf
, count
, off
);
839 static ssize_t
fs_devrw_entry(struct file
*f
, const char __user
*buf
,
840 size_t count
, loff_t
*off
)
842 return do_register_entry(CN_FS_DEVRW
, f
, buf
, count
, off
);
845 static ssize_t
mem_swapout_entry(struct file
*f
, const char __user
*buf
,
846 size_t count
, loff_t
*off
)
848 return do_register_entry(CN_MEM_SWAPOUT
, f
, buf
, count
, off
);
851 static ssize_t
timeradd_entry(struct file
*f
, const char __user
*buf
,
852 size_t count
, loff_t
*off
)
854 return do_register_entry(CN_TIMERADD
, f
, buf
, count
, off
);
857 static ssize_t
scsi_dispatch_cmd_entry(struct file
*f
,
858 const char __user
*buf
, size_t count
, loff_t
*off
)
860 return do_register_entry(CN_SCSI_DISPATCH_CMD
, f
, buf
, count
, off
);
863 static ssize_t
ide_core_cp_entry(struct file
*f
, const char __user
*buf
,
864 size_t count
, loff_t
*off
)
866 return do_register_entry(CN_IDE_CORE_CP
, f
, buf
, count
, off
);
869 /* Special entry to just crash directly. Available without KPROBEs */
870 static ssize_t
direct_entry(struct file
*f
, const char __user
*user_buf
,
871 size_t count
, loff_t
*off
)
876 if (count
>= PAGE_SIZE
)
881 buf
= (char *)__get_free_page(GFP_KERNEL
);
884 if (copy_from_user(buf
, user_buf
, count
)) {
885 free_page((unsigned long) buf
);
888 /* NULL-terminate and remove enter */
892 type
= parse_cp_type(buf
, count
);
893 free_page((unsigned long) buf
);
897 pr_info("Performing direct entry %s\n", cp_type_to_str(type
));
898 lkdtm_do_action(type
);
906 const struct file_operations fops
;
909 static const struct crash_entry crash_entries
[] = {
910 {"DIRECT", {.read
= lkdtm_debugfs_read
,
911 .llseek
= generic_file_llseek
,
912 .open
= lkdtm_debugfs_open
,
913 .write
= direct_entry
} },
914 {"INT_HARDWARE_ENTRY", {.read
= lkdtm_debugfs_read
,
915 .llseek
= generic_file_llseek
,
916 .open
= lkdtm_debugfs_open
,
917 .write
= int_hardware_entry
} },
918 {"INT_HW_IRQ_EN", {.read
= lkdtm_debugfs_read
,
919 .llseek
= generic_file_llseek
,
920 .open
= lkdtm_debugfs_open
,
921 .write
= int_hw_irq_en
} },
922 {"INT_TASKLET_ENTRY", {.read
= lkdtm_debugfs_read
,
923 .llseek
= generic_file_llseek
,
924 .open
= lkdtm_debugfs_open
,
925 .write
= int_tasklet_entry
} },
926 {"FS_DEVRW", {.read
= lkdtm_debugfs_read
,
927 .llseek
= generic_file_llseek
,
928 .open
= lkdtm_debugfs_open
,
929 .write
= fs_devrw_entry
} },
930 {"MEM_SWAPOUT", {.read
= lkdtm_debugfs_read
,
931 .llseek
= generic_file_llseek
,
932 .open
= lkdtm_debugfs_open
,
933 .write
= mem_swapout_entry
} },
934 {"TIMERADD", {.read
= lkdtm_debugfs_read
,
935 .llseek
= generic_file_llseek
,
936 .open
= lkdtm_debugfs_open
,
937 .write
= timeradd_entry
} },
938 {"SCSI_DISPATCH_CMD", {.read
= lkdtm_debugfs_read
,
939 .llseek
= generic_file_llseek
,
940 .open
= lkdtm_debugfs_open
,
941 .write
= scsi_dispatch_cmd_entry
} },
942 {"IDE_CORE_CP", {.read
= lkdtm_debugfs_read
,
943 .llseek
= generic_file_llseek
,
944 .open
= lkdtm_debugfs_open
,
945 .write
= ide_core_cp_entry
} },
948 static struct dentry
*lkdtm_debugfs_root
;
950 static int __init
lkdtm_module_init(void)
953 int n_debugfs_entries
= 1; /* Assume only the direct entry */
956 /* Make sure we can write to __ro_after_init values during __init */
957 ro_after_init
|= 0xAA;
959 /* Register debugfs interface */
960 lkdtm_debugfs_root
= debugfs_create_dir("provoke-crash", NULL
);
961 if (!lkdtm_debugfs_root
) {
962 pr_err("creating root dir failed\n");
966 #ifdef CONFIG_KPROBES
967 n_debugfs_entries
= ARRAY_SIZE(crash_entries
);
970 for (i
= 0; i
< n_debugfs_entries
; i
++) {
971 const struct crash_entry
*cur
= &crash_entries
[i
];
974 de
= debugfs_create_file(cur
->name
, 0644, lkdtm_debugfs_root
,
977 pr_err("could not create %s\n", cur
->name
);
982 if (lkdtm_parse_commandline() == -EINVAL
) {
983 pr_info("Invalid command\n");
987 if (cpoint
!= CN_INVALID
&& cptype
!= CT_NONE
) {
988 ret
= lkdtm_register_cpoint(cpoint
);
990 pr_info("Invalid crash point %d\n", cpoint
);
993 pr_info("Crash point %s of type %s registered\n",
994 cpoint_name
, cpoint_type
);
996 pr_info("No crash points registered, enable through debugfs\n");
1002 debugfs_remove_recursive(lkdtm_debugfs_root
);
1006 static void __exit
lkdtm_module_exit(void)
1008 debugfs_remove_recursive(lkdtm_debugfs_root
);
1010 unregister_jprobe(&lkdtm
);
1011 pr_info("Crash point unregistered\n");
1014 module_init(lkdtm_module_init
);
1015 module_exit(lkdtm_module_exit
);
1017 MODULE_LICENSE("GPL");
1018 MODULE_DESCRIPTION("Kprobe module for testing crash dumps");