drivers/misc/lkdtm_core.c - kernel/msm-5.4 - Gitiles

 /*
  * Linux Kernel Dump Test Module for testing kernel crashes conditions:
  * induces system failures at predefined crashpoints and under predefined
  * operational conditions in order to evaluate the reliability of kernel
  * sanity checking and crash dumps obtained using different dumping
  * solutions.
  *
  * 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>
  *
  * It is adapted from the Linux Kernel Dump Test Tool by
  * Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
  *
  * Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
  *
  * See Documentation/fault-injection/provoke-crashes.txt for instructions
  */
 #include "lkdtm.h"
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/buffer_head.h>
 #include <linux/kprobes.h>
 #include <linux/list.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/hrtimer.h>
 #include <linux/slab.h>
 #include <scsi/scsi_cmnd.h>
 #include <linux/debugfs.h>

 #ifdef CONFIG_IDE
 #include <linux/ide.h>
 #endif

 #define DEFAULT_COUNT 10

 static int lkdtm_debugfs_open(struct inode *inode, struct file *file);
 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
 		size_t count, loff_t *off);
 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
 			    size_t count, loff_t *off);

 #ifdef CONFIG_KPROBES
 static void lkdtm_handler(void);
 static ssize_t lkdtm_debugfs_entry(struct file *f,
 				   const char __user *user_buf,
 				   size_t count, loff_t *off);


 /* jprobe entry point handlers. */
 static unsigned int jp_do_irq(unsigned int irq)
 {
 	lkdtm_handler();
 	jprobe_return();
 	return 0;
 }

 static irqreturn_t jp_handle_irq_event(unsigned int irq,
 				       struct irqaction *action)
 {
 	lkdtm_handler();
 	jprobe_return();
 	return 0;
 }

 static void jp_tasklet_action(struct softirq_action *a)
 {
 	lkdtm_handler();
 	jprobe_return();
 }

 static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 {
 	lkdtm_handler();
 	jprobe_return();
 }

 struct scan_control;

 static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
 					     struct zone *zone,
 					     struct scan_control *sc)
 {
 	lkdtm_handler();
 	jprobe_return();
 	return 0;
 }

 static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
 			    const enum hrtimer_mode mode)
 {
 	lkdtm_handler();
 	jprobe_return();
 	return 0;
 }

 static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 {
 	lkdtm_handler();
 	jprobe_return();
 	return 0;
 }

 # ifdef CONFIG_IDE
 static 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
 #endif

 /* Crash points */
 struct crashpoint {
 	const char *name;
 	const struct file_operations fops;
 	struct jprobe jprobe;
 };

 #define CRASHPOINT(_name, _write, _symbol, _entry)		\
 	{							\
 		.name = _name,					\
 		.fops = {					\
 			.read	= lkdtm_debugfs_read,		\
 			.llseek	= generic_file_llseek,		\
 			.open	= lkdtm_debugfs_open,		\
 			.write	= _write,			\
 		},						\
 		.jprobe = {					\
 			.kp.symbol_name = _symbol,		\
 			.entry = (kprobe_opcode_t *)_entry,	\
 		},						\
 	}

 /* Define the possible places where we can trigger a crash point. */
 struct crashpoint crashpoints[] = {
 	CRASHPOINT("DIRECT",			direct_entry,
 		   NULL,			NULL),
 #ifdef CONFIG_KPROBES
 	CRASHPOINT("INT_HARDWARE_ENTRY",	lkdtm_debugfs_entry,
 		   "do_IRQ",			jp_do_irq),
 	CRASHPOINT("INT_HW_IRQ_EN",		lkdtm_debugfs_entry,
 		   "handle_IRQ_event",		jp_handle_irq_event),
 	CRASHPOINT("INT_TASKLET_ENTRY",		lkdtm_debugfs_entry,
 		   "tasklet_action",		jp_tasklet_action),
 	CRASHPOINT("FS_DEVRW",			lkdtm_debugfs_entry,
 		   "ll_rw_block",		jp_ll_rw_block),
 	CRASHPOINT("MEM_SWAPOUT",		lkdtm_debugfs_entry,
 		   "shrink_inactive_list",	jp_shrink_inactive_list),
 	CRASHPOINT("TIMERADD",			lkdtm_debugfs_entry,
 		   "hrtimer_start",		jp_hrtimer_start),
 	CRASHPOINT("SCSI_DISPATCH_CMD",		lkdtm_debugfs_entry,
 		   "scsi_dispatch_cmd",		jp_scsi_dispatch_cmd),
 # ifdef CONFIG_IDE
 	CRASHPOINT("IDE_CORE_CP",		lkdtm_debugfs_entry,
 		   "generic_ide_ioctl",		jp_generic_ide_ioctl),
 # endif
 #endif
 };


 /* Crash types. */
 struct crashtype {
 	const char *name;
 	void (*func)(void);
 };

 #define CRASHTYPE(_name)			\
 	{					\
 		.name = __stringify(_name),	\
 		.func = lkdtm_ ## _name,	\
 	}

 /* Define the possible types of crashes that can be triggered. */
 struct crashtype crashtypes[] = {
 	CRASHTYPE(PANIC),
 	CRASHTYPE(BUG),
 	CRASHTYPE(WARNING),
 	CRASHTYPE(EXCEPTION),
 	CRASHTYPE(LOOP),
 	CRASHTYPE(OVERFLOW),
 	CRASHTYPE(CORRUPT_LIST_ADD),
 	CRASHTYPE(CORRUPT_LIST_DEL),
 	CRASHTYPE(CORRUPT_USER_DS),
 	CRASHTYPE(CORRUPT_STACK),
 	CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
 	CRASHTYPE(OVERWRITE_ALLOCATION),
 	CRASHTYPE(WRITE_AFTER_FREE),
 	CRASHTYPE(READ_AFTER_FREE),
 	CRASHTYPE(WRITE_BUDDY_AFTER_FREE),
 	CRASHTYPE(READ_BUDDY_AFTER_FREE),
 	CRASHTYPE(SOFTLOCKUP),
 	CRASHTYPE(HARDLOCKUP),
 	CRASHTYPE(SPINLOCKUP),
 	CRASHTYPE(HUNG_TASK),
 	CRASHTYPE(EXEC_DATA),
 	CRASHTYPE(EXEC_STACK),
 	CRASHTYPE(EXEC_KMALLOC),
 	CRASHTYPE(EXEC_VMALLOC),
 	CRASHTYPE(EXEC_RODATA),
 	CRASHTYPE(EXEC_USERSPACE),
 	CRASHTYPE(ACCESS_USERSPACE),
 	CRASHTYPE(WRITE_RO),
 	CRASHTYPE(WRITE_RO_AFTER_INIT),
 	CRASHTYPE(WRITE_KERN),
 	CRASHTYPE(REFCOUNT_SATURATE_INC),
 	CRASHTYPE(REFCOUNT_SATURATE_ADD),
 	CRASHTYPE(REFCOUNT_ZERO_DEC),
 	CRASHTYPE(REFCOUNT_ZERO_INC),
 	CRASHTYPE(REFCOUNT_ZERO_SUB),
 	CRASHTYPE(REFCOUNT_ZERO_ADD),
 	CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
 	CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
 	CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
 	CRASHTYPE(USERCOPY_HEAP_FLAG_FROM),
 	CRASHTYPE(USERCOPY_STACK_FRAME_TO),
 	CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
 	CRASHTYPE(USERCOPY_STACK_BEYOND),
 	CRASHTYPE(USERCOPY_KERNEL),
 };


 /* Global jprobe entry and crashtype. */
 static struct jprobe *lkdtm_jprobe;
 struct crashpoint *lkdtm_crashpoint;
 struct crashtype *lkdtm_crashtype;

 /* Module parameters */
 static int recur_count = -1;
 module_param(recur_count, int, 0644);
 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");

 static char* cpoint_name;
 module_param(cpoint_name, charp, 0444);
 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");

 static char* cpoint_type;
 module_param(cpoint_type, charp, 0444);
 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
 				"hitting the crash point");

 static int cpoint_count = DEFAULT_COUNT;
 module_param(cpoint_count, int, 0644);
 MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
 				"crash point is to be hit to trigger action");


 /* Return the crashtype number or NULL if the name is invalid */
 static struct crashtype *find_crashtype(const char *name)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
 		if (!strcmp(name, crashtypes[i].name))
 			return &crashtypes[i];
 	}

 	return NULL;
 }

 /*
  * This is forced noinline just so it distinctly shows up in the stackdump
  * which makes validation of expected lkdtm crashes easier.
  */
 static noinline void lkdtm_do_action(struct crashtype *crashtype)
 {
 	BUG_ON(!crashtype || !crashtype->func);
 	crashtype->func();
 }

 static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
 				 struct crashtype *crashtype)
 {
 	int ret;

 	/* If this doesn't have a symbol, just call immediately. */
 	if (!crashpoint->jprobe.kp.symbol_name) {
 		lkdtm_do_action(crashtype);
 		return 0;
 	}

 	if (lkdtm_jprobe != NULL)
 		unregister_jprobe(lkdtm_jprobe);

 	lkdtm_crashpoint = crashpoint;
 	lkdtm_crashtype = crashtype;
 	lkdtm_jprobe = &crashpoint->jprobe;
 	ret = register_jprobe(lkdtm_jprobe);
 	if (ret < 0) {
 		pr_info("Couldn't register jprobe %s\n",
 			crashpoint->jprobe.kp.symbol_name);
 		lkdtm_jprobe = NULL;
 		lkdtm_crashpoint = NULL;
 		lkdtm_crashtype = NULL;
 	}

 	return ret;
 }

 #ifdef CONFIG_KPROBES
 /* Global crash counter and spinlock. */
 static int crash_count = DEFAULT_COUNT;
 static DEFINE_SPINLOCK(crash_count_lock);

 /* Called by jprobe entry points. */
 static void lkdtm_handler(void)
 {
 	unsigned long flags;
 	bool do_it = false;

 	BUG_ON(!lkdtm_crashpoint || !lkdtm_crashtype);

 	spin_lock_irqsave(&crash_count_lock, flags);
 	crash_count--;
 	pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
 		lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);

 	if (crash_count == 0) {
 		do_it = true;
 		crash_count = cpoint_count;
 	}
 	spin_unlock_irqrestore(&crash_count_lock, flags);

 	if (do_it)
 		lkdtm_do_action(lkdtm_crashtype);
 }

 static ssize_t lkdtm_debugfs_entry(struct file *f,
 				   const char __user *user_buf,
 				   size_t count, loff_t *off)
 {
 	struct crashpoint *crashpoint = file_inode(f)->i_private;
 	struct crashtype *crashtype = NULL;
 	char *buf;
 	int err;

 	if (count >= PAGE_SIZE)
 		return -EINVAL;

 	buf = (char *)__get_free_page(GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 	if (copy_from_user(buf, user_buf, count)) {
 		free_page((unsigned long) buf);
 		return -EFAULT;
 	}
 	/* NULL-terminate and remove enter */
 	buf[count] = '\0';
 	strim(buf);

 	crashtype = find_crashtype(buf);
 	free_page((unsigned long)buf);

 	if (!crashtype)
 		return -EINVAL;

 	err = lkdtm_register_cpoint(crashpoint, crashtype);
 	if (err < 0)
 		return err;

 	*off += count;

 	return count;
 }
 #endif

 /* Generic read callback that just prints out the available crash types */
 static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
 		size_t count, loff_t *off)
 {
 	char *buf;
 	int i, n, out;

 	buf = (char *)__get_free_page(GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;

 	n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
 	for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
 		n += snprintf(buf + n, PAGE_SIZE - n, "%s\n",
 			      crashtypes[i].name);
 	}
 	buf[n] = '\0';

 	out = simple_read_from_buffer(user_buf, count, off,
 				      buf, n);
 	free_page((unsigned long) buf);

 	return out;
 }

 static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
 {
 	return 0;
 }

 /* Special entry to just crash directly. Available without KPROBEs */
 static ssize_t direct_entry(struct file *f, const char __user *user_buf,
 		size_t count, loff_t *off)
 {
 	struct crashtype *crashtype;
 	char *buf;

 	if (count >= PAGE_SIZE)
 		return -EINVAL;
 	if (count < 1)
 		return -EINVAL;

 	buf = (char *)__get_free_page(GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 	if (copy_from_user(buf, user_buf, count)) {
 		free_page((unsigned long) buf);
 		return -EFAULT;
 	}
 	/* NULL-terminate and remove enter */
 	buf[count] = '\0';
 	strim(buf);

 	crashtype = find_crashtype(buf);
 	free_page((unsigned long) buf);
 	if (!crashtype)
 		return -EINVAL;

 	pr_info("Performing direct entry %s\n", crashtype->name);
 	lkdtm_do_action(crashtype);
 	*off += count;

 	return count;
 }

 static struct dentry *lkdtm_debugfs_root;

 static int __init lkdtm_module_init(void)
 {
 	struct crashpoint *crashpoint = NULL;
 	struct crashtype *crashtype = NULL;
 	int ret = -EINVAL;
 	int i;

 	/* Neither or both of these need to be set */
 	if ((cpoint_type || cpoint_name) && !(cpoint_type && cpoint_name)) {
 		pr_err("Need both cpoint_type and cpoint_name or neither\n");
 		return -EINVAL;
 	}

 	if (cpoint_type) {
 		crashtype = find_crashtype(cpoint_type);
 		if (!crashtype) {
 			pr_err("Unknown crashtype '%s'\n", cpoint_type);
 			return -EINVAL;
 		}
 	}

 	if (cpoint_name) {
 		for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
 			if (!strcmp(cpoint_name, crashpoints[i].name))
 				crashpoint = &crashpoints[i];
 		}

 		/* Refuse unknown crashpoints. */
 		if (!crashpoint) {
 			pr_err("Invalid crashpoint %s\n", cpoint_name);
 			return -EINVAL;
 		}
 	}

 #ifdef CONFIG_KPROBES
 	/* Set crash count. */
 	crash_count = cpoint_count;
 #endif

 	/* Handle test-specific initialization. */
 	lkdtm_bugs_init(&recur_count);
 	lkdtm_perms_init();
 	lkdtm_usercopy_init();

 	/* Register debugfs interface */
 	lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
 	if (!lkdtm_debugfs_root) {
 		pr_err("creating root dir failed\n");
 		return -ENODEV;
 	}

 	/* Install debugfs trigger files. */
 	for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
 		struct crashpoint *cur = &crashpoints[i];
 		struct dentry *de;

 		de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
 					 cur, &cur->fops);
 		if (de == NULL) {
 			pr_err("could not create crashpoint %s\n", cur->name);
 			goto out_err;
 		}
 	}

 	/* Install crashpoint if one was selected. */
 	if (crashpoint) {
 		ret = lkdtm_register_cpoint(crashpoint, crashtype);
 		if (ret < 0) {
 			pr_info("Invalid crashpoint %s\n", crashpoint->name);
 			goto out_err;
 		}
 		pr_info("Crash point %s of type %s registered\n",
 			crashpoint->name, cpoint_type);
 	} else {
 		pr_info("No crash points registered, enable through debugfs\n");
 	}

 	return 0;

 out_err:
 	debugfs_remove_recursive(lkdtm_debugfs_root);
 	return ret;
 }

 static void __exit lkdtm_module_exit(void)
 {
 	debugfs_remove_recursive(lkdtm_debugfs_root);

 	/* Handle test-specific clean-up. */
 	lkdtm_usercopy_exit();

 	if (lkdtm_jprobe != NULL)
 		unregister_jprobe(lkdtm_jprobe);

 	pr_info("Crash point unregistered\n");
 }

 module_init(lkdtm_module_init);
 module_exit(lkdtm_module_exit);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Kernel crash testing module");
	/*
	* Linux Kernel Dump Test Module for testing kernel crashes conditions:
	* induces system failures at predefined crashpoints and under predefined
	* operational conditions in order to evaluate the reliability of kernel
	* sanity checking and crash dumps obtained using different dumping
	* solutions.
	*
	* 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>
	*
	* It is adapted from the Linux Kernel Dump Test Tool by
	* Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
	*
	* Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
	*
	* See Documentation/fault-injection/provoke-crashes.txt for instructions
	*/
	#include "lkdtm.h"
	#include <linux/fs.h>
	#include <linux/module.h>
	#include <linux/buffer_head.h>
	#include <linux/kprobes.h>
	#include <linux/list.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/hrtimer.h>
	#include <linux/slab.h>
	#include <scsi/scsi_cmnd.h>
	#include <linux/debugfs.h>

	#ifdef CONFIG_IDE
	#include <linux/ide.h>
	#endif

	#define DEFAULT_COUNT 10

	static int lkdtm_debugfs_open(struct inode inode, struct file file);
	static ssize_t lkdtm_debugfs_read(struct file f, char __user user_buf,
	size_t count, loff_t *off);
	static ssize_t direct_entry(struct file f, const char __user user_buf,
	size_t count, loff_t *off);

	#ifdef CONFIG_KPROBES
	static void lkdtm_handler(void);
	static ssize_t lkdtm_debugfs_entry(struct file *f,
	const char __user *user_buf,
	size_t count, loff_t *off);


	/* jprobe entry point handlers. */
	static unsigned int jp_do_irq(unsigned int irq)
	{
	lkdtm_handler();
	jprobe_return();
	return 0;
	}

	static irqreturn_t jp_handle_irq_event(unsigned int irq,
	struct irqaction *action)
	{
	lkdtm_handler();
	jprobe_return();
	return 0;
	}

	static void jp_tasklet_action(struct softirq_action *a)
	{
	lkdtm_handler();
	jprobe_return();
	}

	static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
	{
	lkdtm_handler();
	jprobe_return();
	}

	struct scan_control;

	static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
	struct zone *zone,
	struct scan_control *sc)
	{
	lkdtm_handler();
	jprobe_return();
	return 0;
	}

	static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
	const enum hrtimer_mode mode)
	{
	lkdtm_handler();
	jprobe_return();
	return 0;
	}

	static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
	{
	lkdtm_handler();
	jprobe_return();
	return 0;
	}

	# ifdef CONFIG_IDE
	static 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
	#endif

	/* Crash points */
	struct crashpoint {
	const char *name;
	const struct file_operations fops;
	struct jprobe jprobe;
	};

	#define CRASHPOINT(_name, _write, _symbol, _entry) \
	{ \
	.name = _name, \
	.fops = { \
	.read = lkdtm_debugfs_read, \
	.llseek = generic_file_llseek, \
	.open = lkdtm_debugfs_open, \
	.write = _write, \
	}, \
	.jprobe = { \
	.kp.symbol_name = _symbol, \
	.entry = (kprobe_opcode_t *)_entry, \
	}, \
	}

	/* Define the possible places where we can trigger a crash point. */
	struct crashpoint crashpoints[] = {
	CRASHPOINT("DIRECT", direct_entry,
	NULL, NULL),
	#ifdef CONFIG_KPROBES
	CRASHPOINT("INT_HARDWARE_ENTRY", lkdtm_debugfs_entry,
	"do_IRQ", jp_do_irq),
	CRASHPOINT("INT_HW_IRQ_EN", lkdtm_debugfs_entry,
	"handle_IRQ_event", jp_handle_irq_event),
	CRASHPOINT("INT_TASKLET_ENTRY", lkdtm_debugfs_entry,
	"tasklet_action", jp_tasklet_action),
	CRASHPOINT("FS_DEVRW", lkdtm_debugfs_entry,
	"ll_rw_block", jp_ll_rw_block),
	CRASHPOINT("MEM_SWAPOUT", lkdtm_debugfs_entry,
	"shrink_inactive_list", jp_shrink_inactive_list),
	CRASHPOINT("TIMERADD", lkdtm_debugfs_entry,
	"hrtimer_start", jp_hrtimer_start),
	CRASHPOINT("SCSI_DISPATCH_CMD", lkdtm_debugfs_entry,
	"scsi_dispatch_cmd", jp_scsi_dispatch_cmd),
	# ifdef CONFIG_IDE
	CRASHPOINT("IDE_CORE_CP", lkdtm_debugfs_entry,
	"generic_ide_ioctl", jp_generic_ide_ioctl),
	# endif
	#endif
	};


	/* Crash types. */
	struct crashtype {
	const char *name;
	void (*func)(void);
	};

	#define CRASHTYPE(_name) \
	{ \
	.name = __stringify(_name), \
	.func = lkdtm_ ## _name, \
	}

	/* Define the possible types of crashes that can be triggered. */
	struct crashtype crashtypes[] = {
	CRASHTYPE(PANIC),
	CRASHTYPE(BUG),
	CRASHTYPE(WARNING),
	CRASHTYPE(EXCEPTION),
	CRASHTYPE(LOOP),
	CRASHTYPE(OVERFLOW),
	CRASHTYPE(CORRUPT_LIST_ADD),
	CRASHTYPE(CORRUPT_LIST_DEL),
	CRASHTYPE(CORRUPT_USER_DS),
	CRASHTYPE(CORRUPT_STACK),
	CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
	CRASHTYPE(OVERWRITE_ALLOCATION),
	CRASHTYPE(WRITE_AFTER_FREE),
	CRASHTYPE(READ_AFTER_FREE),
	CRASHTYPE(WRITE_BUDDY_AFTER_FREE),
	CRASHTYPE(READ_BUDDY_AFTER_FREE),
	CRASHTYPE(SOFTLOCKUP),
	CRASHTYPE(HARDLOCKUP),
	CRASHTYPE(SPINLOCKUP),
	CRASHTYPE(HUNG_TASK),
	CRASHTYPE(EXEC_DATA),
	CRASHTYPE(EXEC_STACK),
	CRASHTYPE(EXEC_KMALLOC),
	CRASHTYPE(EXEC_VMALLOC),
	CRASHTYPE(EXEC_RODATA),
	CRASHTYPE(EXEC_USERSPACE),
	CRASHTYPE(ACCESS_USERSPACE),
	CRASHTYPE(WRITE_RO),
	CRASHTYPE(WRITE_RO_AFTER_INIT),
	CRASHTYPE(WRITE_KERN),
	CRASHTYPE(REFCOUNT_SATURATE_INC),
	CRASHTYPE(REFCOUNT_SATURATE_ADD),
	CRASHTYPE(REFCOUNT_ZERO_DEC),
	CRASHTYPE(REFCOUNT_ZERO_INC),
	CRASHTYPE(REFCOUNT_ZERO_SUB),
	CRASHTYPE(REFCOUNT_ZERO_ADD),
	CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
	CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
	CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
	CRASHTYPE(USERCOPY_HEAP_FLAG_FROM),
	CRASHTYPE(USERCOPY_STACK_FRAME_TO),
	CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
	CRASHTYPE(USERCOPY_STACK_BEYOND),
	CRASHTYPE(USERCOPY_KERNEL),
	};


	/* Global jprobe entry and crashtype. */
	static struct jprobe *lkdtm_jprobe;
	struct crashpoint *lkdtm_crashpoint;
	struct crashtype *lkdtm_crashtype;

	/* Module parameters */
	static int recur_count = -1;
	module_param(recur_count, int, 0644);
	MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");

	static char* cpoint_name;
	module_param(cpoint_name, charp, 0444);
	MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");

	static char* cpoint_type;
	module_param(cpoint_type, charp, 0444);
	MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
	"hitting the crash point");

	static int cpoint_count = DEFAULT_COUNT;
	module_param(cpoint_count, int, 0644);
	MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
	"crash point is to be hit to trigger action");


	/* Return the crashtype number or NULL if the name is invalid */
	static struct crashtype find_crashtype(const char name)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
	if (!strcmp(name, crashtypes[i].name))
	return &crashtypes[i];
	}

	return NULL;
	}

	/*
	* This is forced noinline just so it distinctly shows up in the stackdump
	* which makes validation of expected lkdtm crashes easier.
	*/
	static noinline void lkdtm_do_action(struct crashtype *crashtype)
	{
	BUG_ON(!crashtype \|\| !crashtype->func);
	crashtype->func();
	}

	static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
	struct crashtype *crashtype)
	{
	int ret;

	/* If this doesn't have a symbol, just call immediately. */
	if (!crashpoint->jprobe.kp.symbol_name) {
	lkdtm_do_action(crashtype);
	return 0;
	}

	if (lkdtm_jprobe != NULL)
	unregister_jprobe(lkdtm_jprobe);

	lkdtm_crashpoint = crashpoint;
	lkdtm_crashtype = crashtype;
	lkdtm_jprobe = &crashpoint->jprobe;
	ret = register_jprobe(lkdtm_jprobe);
	if (ret < 0) {
	pr_info("Couldn't register jprobe %s\n",
	crashpoint->jprobe.kp.symbol_name);
	lkdtm_jprobe = NULL;
	lkdtm_crashpoint = NULL;
	lkdtm_crashtype = NULL;
	}

	return ret;
	}

	#ifdef CONFIG_KPROBES
	/* Global crash counter and spinlock. */
	static int crash_count = DEFAULT_COUNT;
	static DEFINE_SPINLOCK(crash_count_lock);

	/* Called by jprobe entry points. */
	static void lkdtm_handler(void)
	{
	unsigned long flags;
	bool do_it = false;

	BUG_ON(!lkdtm_crashpoint \|\| !lkdtm_crashtype);

	spin_lock_irqsave(&crash_count_lock, flags);
	crash_count--;
	pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
	lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);

	if (crash_count == 0) {
	do_it = true;
	crash_count = cpoint_count;
	}
	spin_unlock_irqrestore(&crash_count_lock, flags);

	if (do_it)
	lkdtm_do_action(lkdtm_crashtype);
	}

	static ssize_t lkdtm_debugfs_entry(struct file *f,
	const char __user *user_buf,
	size_t count, loff_t *off)
	{
	struct crashpoint *crashpoint = file_inode(f)->i_private;
	struct crashtype *crashtype = NULL;
	char *buf;
	int err;

	if (count >= PAGE_SIZE)
	return -EINVAL;

	buf = (char *)__get_free_page(GFP_KERNEL);
	if (!buf)
	return -ENOMEM;
	if (copy_from_user(buf, user_buf, count)) {
	free_page((unsigned long) buf);
	return -EFAULT;
	}
	/* NULL-terminate and remove enter */
	buf[count] = '\0';
	strim(buf);

	crashtype = find_crashtype(buf);
	free_page((unsigned long)buf);

	if (!crashtype)
	return -EINVAL;

	err = lkdtm_register_cpoint(crashpoint, crashtype);
	if (err < 0)
	return err;

	*off += count;

	return count;
	}
	#endif

	/* Generic read callback that just prints out the available crash types */
	static ssize_t lkdtm_debugfs_read(struct file f, char __user user_buf,
	size_t count, loff_t *off)
	{
	char *buf;
	int i, n, out;

	buf = (char *)__get_free_page(GFP_KERNEL);
	if (buf == NULL)
	return -ENOMEM;

	n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
	for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
	n += snprintf(buf + n, PAGE_SIZE - n, "%s\n",
	crashtypes[i].name);
	}
	buf[n] = '\0';

	out = simple_read_from_buffer(user_buf, count, off,
	buf, n);
	free_page((unsigned long) buf);

	return out;
	}

	static int lkdtm_debugfs_open(struct inode inode, struct file file)
	{
	return 0;
	}

	/* Special entry to just crash directly. Available without KPROBEs */
	static ssize_t direct_entry(struct file f, const char __user user_buf,
	size_t count, loff_t *off)
	{
	struct crashtype *crashtype;
	char *buf;

	if (count >= PAGE_SIZE)
	return -EINVAL;
	if (count < 1)
	return -EINVAL;

	buf = (char *)__get_free_page(GFP_KERNEL);
	if (!buf)
	return -ENOMEM;
	if (copy_from_user(buf, user_buf, count)) {
	free_page((unsigned long) buf);
	return -EFAULT;
	}
	/* NULL-terminate and remove enter */
	buf[count] = '\0';
	strim(buf);

	crashtype = find_crashtype(buf);
	free_page((unsigned long) buf);
	if (!crashtype)
	return -EINVAL;

	pr_info("Performing direct entry %s\n", crashtype->name);
	lkdtm_do_action(crashtype);
	*off += count;

	return count;
	}

	static struct dentry *lkdtm_debugfs_root;

	static int __init lkdtm_module_init(void)
	{
	struct crashpoint *crashpoint = NULL;
	struct crashtype *crashtype = NULL;
	int ret = -EINVAL;
	int i;

	/* Neither or both of these need to be set */
	if ((cpoint_type \|\| cpoint_name) && !(cpoint_type && cpoint_name)) {
	pr_err("Need both cpoint_type and cpoint_name or neither\n");
	return -EINVAL;
	}

	if (cpoint_type) {
	crashtype = find_crashtype(cpoint_type);
	if (!crashtype) {
	pr_err("Unknown crashtype '%s'\n", cpoint_type);
	return -EINVAL;
	}
	}

	if (cpoint_name) {
	for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
	if (!strcmp(cpoint_name, crashpoints[i].name))
	crashpoint = &crashpoints[i];
	}

	/* Refuse unknown crashpoints. */
	if (!crashpoint) {
	pr_err("Invalid crashpoint %s\n", cpoint_name);
	return -EINVAL;
	}
	}

	#ifdef CONFIG_KPROBES
	/* Set crash count. */
	crash_count = cpoint_count;
	#endif

	/* Handle test-specific initialization. */
	lkdtm_bugs_init(&recur_count);
	lkdtm_perms_init();
	lkdtm_usercopy_init();

	/* Register debugfs interface */
	lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
	if (!lkdtm_debugfs_root) {
	pr_err("creating root dir failed\n");
	return -ENODEV;
	}

	/* Install debugfs trigger files. */
	for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
	struct crashpoint *cur = &crashpoints[i];
	struct dentry *de;

	de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
	cur, &cur->fops);
	if (de == NULL) {
	pr_err("could not create crashpoint %s\n", cur->name);
	goto out_err;
	}
	}

	/* Install crashpoint if one was selected. */
	if (crashpoint) {
	ret = lkdtm_register_cpoint(crashpoint, crashtype);
	if (ret < 0) {
	pr_info("Invalid crashpoint %s\n", crashpoint->name);
	goto out_err;
	}
	pr_info("Crash point %s of type %s registered\n",
	crashpoint->name, cpoint_type);
	} else {
	pr_info("No crash points registered, enable through debugfs\n");
	}

	return 0;

	out_err:
	debugfs_remove_recursive(lkdtm_debugfs_root);
	return ret;
	}

	static void __exit lkdtm_module_exit(void)
	{
	debugfs_remove_recursive(lkdtm_debugfs_root);

	/* Handle test-specific clean-up. */
	lkdtm_usercopy_exit();

	if (lkdtm_jprobe != NULL)
	unregister_jprobe(lkdtm_jprobe);

	pr_info("Crash point unregistered\n");
	}

	module_init(lkdtm_module_init);
	module_exit(lkdtm_module_exit);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Kernel crash testing module");