/*
* Kprobe module for testing crash dumps
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2006
*
* Author: Ankita Garg <ankita@in.ibm.com>
*
* This module induces system failures at predefined crashpoints to
* evaluate the reliability of crash dumps obtained using different dumping
* solutions.
*
* It is adapted from the Linux Kernel Dump Test Tool by
* Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
*
* Usage : insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
* [cpoint_count={>0}]
*
* recur_count : Recursion level for the stack overflow test. Default is 10.
*
* cpoint_name : Crash point where the kernel is to be crashed. It can be
* one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
* FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
* IDE_CORE_CP
*
* cpoint_type : Indicates the action to be taken on hitting the crash point.
* It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW
*
* cpoint_count : Indicates the number of times the crash point is to be hit
* to trigger an action. The default is 10.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <scsi/scsi_cmnd.h>
#ifdef CONFIG_IDE
#include <linux/ide.h>
#endif
#define NUM_CPOINTS 8
#define NUM_CPOINT_TYPES 5
#define DEFAULT_COUNT 10
#define REC_NUM_DEFAULT 10
enum cname {
INVALID,
INT_HARDWARE_ENTRY,
INT_HW_IRQ_EN,
INT_TASKLET_ENTRY,
FS_DEVRW,
MEM_SWAPOUT,
TIMERADD,
SCSI_DISPATCH_CMD,
IDE_CORE_CP
};
enum ctype {
NONE,
PANIC,
BUG,
EXCEPTION,
LOOP,
OVERFLOW
};
static char* cp_name[] = {
"INT_HARDWARE_ENTRY",
"INT_HW_IRQ_EN",
"INT_TASKLET_ENTRY",
"FS_DEVRW",
"MEM_SWAPOUT",
"TIMERADD",
"SCSI_DISPATCH_CMD",
"IDE_CORE_CP"
};
static char* cp_type[] = {
"PANIC",
"BUG",
"EXCEPTION",
"LOOP",
"OVERFLOW"
};
static struct jprobe lkdtm;
static int lkdtm_parse_commandline(void);
static void lkdtm_handler(void);
static char* cpoint_name = INVALID;
static char* cpoint_type = NONE;
static int cpoint_count = DEFAULT_COUNT;
static int recur_count = REC_NUM_DEFAULT;
static enum cname cpoint = INVALID;
static enum ctype cptype = NONE;
static int count = DEFAULT_COUNT;
module_param(recur_count, int, 0644);
MODULE_PARM_DESC(recur_count, "Recurcion level for the stack overflow test,\
default is 10");
module_param(cpoint_name, charp, 0644);
MODULE_PARM_DESC(cpoint_name, "Crash Point, where kernel is to be crashed");
module_param(cpoint_type, charp, 06444);
MODULE_PARM_DESC(cpoint_type, "Crash Point Type, action to be taken on\
hitting the crash point");
module_param(cpoint_count, int, 06444);
MODULE_PARM_DESC(cpoint_count, "Crash Point Count, number of times the \
crash point is to be hit to trigger action");
unsigned int jp_do_irq(unsigned int irq)
{
lkdtm_handler();
jprobe_return();
return 0;
}
irqreturn_t jp_handle_irq_event(unsigned int irq, struct irqaction *action)
{
lkdtm_handler();
jprobe_return();
return 0;
}
void jp_tasklet_action(struct softirq_action *a)
{
lkdtm_handler();
jprobe_return();
}
void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
{
lkdtm_handler();
jprobe_return();
}
struct scan_control;
unsigned long jp_shrink_page_list(struct list_head *page_list,
struct scan_control *sc)
{
lkdtm_handler();
jprobe_return();
return 0;
}
int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
const enum hrtimer_mode mode)
{
lkdtm_handler();
jprobe_return();
return 0;
}
int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
{
lkdtm_handler();
jprobe_return();
return 0;
}
#ifdef CONFIG_IDE
int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
struct block_device *bdev, unsigned int cmd,
unsigned long arg)
{
lkdtm_handler();
jprobe_return();
return 0;
}
#endif
static int lkdtm_parse_commandline(void)
{
int i;
if (cpoint_name == INVALID || cpoint_type == NONE ||
cpoint_count < 1 || recur_count < 1)
return -EINVAL;
for (i = 0; i < NUM_CPOINTS; ++i) {
if (!strcmp(cpoint_name, cp_name[i])) {
cpoint = i + 1;
break;
}
}
for (i = 0; i < NUM_CPOINT_TYPES; ++i) {
if (!strcmp(cpoint_type, cp_type[i])) {
cptype = i + 1;
break;
}
}
if (cpoint == INVALID || cptype == NONE)
return -EINVAL;
count = cpoint_count;
return 0;
}
static int recursive_loop(int a)
{
char buf[1024];
memset(buf,0xFF,1024);
recur_count--;
if (!recur_count)
return 0;
else
return recursive_loop(a);
}
void lkdtm_handler(void)
{
printk(KERN_INFO "lkdtm : Crash point %s of type %s hit\n",
cpoint_name, cpoint_type);
--count;
if (count == 0) {
switch (cptype) {
case NONE:
break;
case PANIC:
printk(KERN_INFO "lkdtm : PANIC\n");
panic("dumptest");
break;
case BUG:
printk(KERN_INFO "lkdtm : BUG\n");
BUG();
break;
case EXCEPTION:
printk(KERN_INFO "lkdtm : EXCEPTION\n");
*((int *) 0) = 0;
break;
case LOOP:
printk(KERN_INFO "lkdtm : LOOP\n");
for (;;);
break;
case OVERFLOW:
printk(KERN_INFO "lkdtm : OVERFLOW\n");
(void) recursive_loop(0);
break;
default:
break;
}
count = cpoint_count;
}
}
int lkdtm_module_init(void)
{
int ret;
if (lkdtm_parse_commandline() == -EINVAL) {
printk(KERN_INFO "lkdtm : Invalid command\n");
return -EINVAL;
}
switch (cpoint) {
case INT_HARDWARE_ENTRY:
lkdtm.kp.symbol_name = "__do_IRQ";
lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
break;
case INT_HW_IRQ_EN:
lkdtm.kp.symbol_name = "handle_IRQ_event";
lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
break;
case INT_TASKLET_ENTRY:
lkdtm.kp.symbol_name = "tasklet_action";
lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
break;
case FS_DEVRW:
lkdtm.kp.symbol_name = "ll_rw_block";
lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
break;
case MEM_SWAPOUT:
lkdtm.kp.symbol_name = "shrink_page_list";
lkdtm.entry = (kprobe_opcode_t*) jp_shrink_page_list;
break;
case TIMERADD:
lkdtm.kp.symbol_name = "hrtimer_start";
lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
break;
case SCSI_DISPATCH_CMD:
lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
break;
case IDE_CORE_CP:
#ifdef CONFIG_IDE
lkdtm.kp.symbol_name = "generic_ide_ioctl";
lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
#else
printk(KERN_INFO "lkdtm : Crash point not available\n");
#endif
break;
default:
printk(KERN_INFO "lkdtm : Invalid Crash Point\n");
break;
}
if ((ret = register_jprobe(&lkdtm)) < 0) {
printk(KERN_INFO "lkdtm : Couldn't register jprobe\n");
return ret;
}
printk(KERN_INFO "lkdtm : Crash point %s of type %s registered\n",
cpoint_name, cpoint_type);
return 0;
}
void lkdtm_module_exit(void)
{
unregister_jprobe(&lkdtm);
printk(KERN_INFO "lkdtm : Crash point unregistered\n");
}
module_init(lkdtm_module_init);
module_exit(lkdtm_module_exit);
MODULE_LICENSE("GPL");
