misc: nct1008: Refactor power rail control
[linux-2.6.git] / drivers / misc / lkdtm.c
index db9d7df..28adefe 100644 (file)
  * 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}]
+ * Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
  *
- * 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.
+ * See Documentation/fault-injection/provoke-crashes.txt for instructions
  */
 
 #include <linux/kernel.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 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
+       CN_INVALID,
+       CN_INT_HARDWARE_ENTRY,
+       CN_INT_HW_IRQ_EN,
+       CN_INT_TASKLET_ENTRY,
+       CN_FS_DEVRW,
+       CN_MEM_SWAPOUT,
+       CN_TIMERADD,
+       CN_SCSI_DISPATCH_CMD,
+       CN_IDE_CORE_CP,
+       CN_DIRECT,
 };
 
 enum ctype {
-       NONE,
-       PANIC,
-       BUG,
-       EXCEPTION,
-       LOOP,
-       OVERFLOW
+       CT_NONE,
+       CT_PANIC,
+       CT_BUG,
+       CT_EXCEPTION,
+       CT_LOOP,
+       CT_OVERFLOW,
+       CT_CORRUPT_STACK,
+       CT_UNALIGNED_LOAD_STORE_WRITE,
+       CT_OVERWRITE_ALLOCATION,
+       CT_WRITE_AFTER_FREE,
+       CT_SOFTLOCKUP,
+       CT_HARDLOCKUP,
+       CT_HUNG_TASK,
 };
 
 static char* cp_name[] = {
@@ -92,7 +88,8 @@ static char* cp_name[] = {
        "MEM_SWAPOUT",
        "TIMERADD",
        "SCSI_DISPATCH_CMD",
-       "IDE_CORE_CP"
+       "IDE_CORE_CP",
+       "DIRECT",
 };
 
 static char* cp_type[] = {
@@ -100,7 +97,14 @@ static char* cp_type[] = {
        "BUG",
        "EXCEPTION",
        "LOOP",
-       "OVERFLOW"
+       "OVERFLOW",
+       "CORRUPT_STACK",
+       "UNALIGNED_LOAD_STORE_WRITE",
+       "OVERWRITE_ALLOCATION",
+       "WRITE_AFTER_FREE",
+       "SOFTLOCKUP",
+       "HARDLOCKUP",
+       "HUNG_TASK",
 };
 
 static struct jprobe lkdtm;
@@ -108,48 +112,50 @@ 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 char* cpoint_name;
+static char* cpoint_type;
 static int cpoint_count = DEFAULT_COUNT;
 static int recur_count = REC_NUM_DEFAULT;
 
-static enum cname cpoint = INVALID;
-static enum ctype cptype = NONE;
+static enum cname cpoint = CN_INVALID;
+static enum ctype cptype = CT_NONE;
 static int count = DEFAULT_COUNT;
+static DEFINE_SPINLOCK(count_lock);
 
 module_param(recur_count, int, 0644);
 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test, "\
                                 "default is 10");
-module_param(cpoint_name, charp, 0644);
+module_param(cpoint_name, charp, 0444);
 MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
-module_param(cpoint_type, charp, 0644);
+module_param(cpoint_type, charp, 0444);
 MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
                                "hitting the crash point");
 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");
 
-unsigned int jp_do_irq(unsigned int irq)
+static 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)
+static 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)
+static 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[])
+static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 {
        lkdtm_handler();
        jprobe_return();
@@ -157,23 +163,24 @@ void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 
 struct scan_control;
 
-unsigned long jp_shrink_inactive_list(unsigned long max_scan,
-                               struct zone *zone, struct scan_control *sc)
+static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
+                                            struct zone *zone,
+                                            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)
+static 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)
+static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 {
        lkdtm_handler();
        jprobe_return();
@@ -191,34 +198,69 @@ int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
 }
 #endif
 
+/* Return the crashpoint number or NONE if the name is invalid */
+static enum ctype parse_cp_type(const char *what, size_t count)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
+               if (!strcmp(what, cp_type[i]))
+                       return i + 1;
+       }
+
+       return CT_NONE;
+}
+
+static const char *cp_type_to_str(enum ctype type)
+{
+       if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
+               return "None";
+
+       return cp_type[type - 1];
+}
+
+static const char *cp_name_to_str(enum cname name)
+{
+       if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
+               return "INVALID";
+
+       return cp_name[name - 1];
+}
+
+
 static int lkdtm_parse_commandline(void)
 {
        int i;
+       unsigned long flags;
 
-       if (cpoint_name == INVALID || cpoint_type == NONE ||
-                                       cpoint_count < 1 || recur_count < 1)
+       if (cpoint_count < 1 || recur_count < 1)
                return -EINVAL;
 
-       for (i = 0; i < NUM_CPOINTS; ++i) {
+       spin_lock_irqsave(&count_lock, flags);
+       count = cpoint_count;
+       spin_unlock_irqrestore(&count_lock, flags);
+
+       /* No special parameters */
+       if (!cpoint_type && !cpoint_name)
+               return 0;
+
+       /* Neither or both of these need to be set */
+       if (!cpoint_type || !cpoint_name)
+               return -EINVAL;
+
+       cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
+       if (cptype == CT_NONE)
+               return -EINVAL;
+
+       for (i = 0; i < ARRAY_SIZE(cp_name); 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;
+                       return 0;
                }
        }
 
-       if (cpoint == INVALID || cptype == NONE)
-                return -EINVAL;
-
-       count = cpoint_count;
-
-       return 0;
+       /* Could not find a valid crash point */
+       return -EINVAL;
 }
 
 static int recursive_loop(int a)
@@ -233,108 +275,418 @@ static int recursive_loop(int a)
                return recursive_loop(a);
 }
 
-void lkdtm_handler(void)
+static void lkdtm_do_action(enum ctype which)
+{
+       switch (which) {
+       case CT_PANIC:
+               panic("dumptest");
+               break;
+       case CT_BUG:
+               BUG();
+               break;
+       case CT_EXCEPTION:
+               *((int *) 0) = 0;
+               break;
+       case CT_LOOP:
+               for (;;)
+                       ;
+               break;
+       case CT_OVERFLOW:
+               (void) recursive_loop(0);
+               break;
+       case CT_CORRUPT_STACK: {
+               volatile u32 data[8];
+               volatile u32 *p = data;
+
+               p[12] = 0x12345678;
+               break;
+       }
+       case CT_UNALIGNED_LOAD_STORE_WRITE: {
+               static u8 data[5] __attribute__((aligned(4))) = {1, 2,
+                               3, 4, 5};
+               u32 *p;
+               u32 val = 0x12345678;
+
+               p = (u32 *)(data + 1);
+               if (*p == 0)
+                       val = 0x87654321;
+               *p = val;
+                break;
+       }
+       case CT_OVERWRITE_ALLOCATION: {
+               size_t len = 1020;
+               u32 *data = kmalloc(len, GFP_KERNEL);
+
+               data[1024 / sizeof(u32)] = 0x12345678;
+               kfree(data);
+               break;
+       }
+       case CT_WRITE_AFTER_FREE: {
+               size_t len = 1024;
+               u32 *data = kmalloc(len, GFP_KERNEL);
+
+               kfree(data);
+               schedule();
+               memset(data, 0x78, len);
+               break;
+       }
+       case CT_SOFTLOCKUP:
+               preempt_disable();
+               for (;;)
+                       cpu_relax();
+               break;
+       case CT_HARDLOCKUP:
+               local_irq_disable();
+               for (;;)
+                       cpu_relax();
+               break;
+       case CT_HUNG_TASK:
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule();
+               break;
+       case CT_NONE:
+       default:
+               break;
+       }
+
+}
+
+static void lkdtm_handler(void)
 {
-       printk(KERN_INFO "lkdtm : Crash point %s of type %s hit\n",
-                                        cpoint_name, cpoint_type);
-       --count;
+       unsigned long flags;
+       bool do_it = false;
+
+       spin_lock_irqsave(&count_lock, flags);
+       count--;
+       printk(KERN_INFO "lkdtm: Crash point %s of type %s hit, trigger in %d rounds\n",
+                       cp_name_to_str(cpoint), cp_type_to_str(cptype), 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;
-               }
+               do_it = true;
                count = cpoint_count;
        }
+       spin_unlock_irqrestore(&count_lock, flags);
+
+       if (do_it)
+               lkdtm_do_action(cptype);
 }
 
-int lkdtm_module_init(void)
+static int lkdtm_register_cpoint(enum cname which)
 {
        int ret;
 
-       if (lkdtm_parse_commandline() == -EINVAL) {
-               printk(KERN_INFO "lkdtm : Invalid command\n");
-               return -EINVAL;
-       }
+       cpoint = CN_INVALID;
+       if (lkdtm.entry != NULL)
+               unregister_jprobe(&lkdtm);
 
-       switch (cpoint) {
-       case INT_HARDWARE_ENTRY:
-               lkdtm.kp.symbol_name = "__do_IRQ";
+       switch (which) {
+       case CN_DIRECT:
+               lkdtm_do_action(cptype);
+               return 0;
+       case CN_INT_HARDWARE_ENTRY:
+               lkdtm.kp.symbol_name = "do_IRQ";
                lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
                break;
-       case INT_HW_IRQ_EN:
+       case CN_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:
+       case CN_INT_TASKLET_ENTRY:
                lkdtm.kp.symbol_name = "tasklet_action";
                lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
                break;
-       case FS_DEVRW:
+       case CN_FS_DEVRW:
                lkdtm.kp.symbol_name = "ll_rw_block";
                lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
                break;
-       case MEM_SWAPOUT:
+       case CN_MEM_SWAPOUT:
                lkdtm.kp.symbol_name = "shrink_inactive_list";
                lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
                break;
-       case TIMERADD:
+       case CN_TIMERADD:
                lkdtm.kp.symbol_name = "hrtimer_start";
                lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
                break;
-       case SCSI_DISPATCH_CMD:
+       case CN_SCSI_DISPATCH_CMD:
                lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
                lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
                break;
-       case IDE_CORE_CP:
+       case CN_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");
+               printk(KERN_INFO "lkdtm: Crash point not available\n");
+               return -EINVAL;
 #endif
                break;
        default:
-               printk(KERN_INFO "lkdtm : Invalid Crash Point\n");
-               break;
+               printk(KERN_INFO "lkdtm: Invalid Crash Point\n");
+               return -EINVAL;
        }
 
+       cpoint = which;
        if ((ret = register_jprobe(&lkdtm)) < 0) {
-                printk(KERN_INFO "lkdtm : Couldn't register jprobe\n");
-                return ret;
+               printk(KERN_INFO "lkdtm: Couldn't register jprobe\n");
+               cpoint = CN_INVALID;
+       }
+
+       return ret;
+}
+
+static ssize_t do_register_entry(enum cname which, struct file *f,
+               const char __user *user_buf, size_t count, loff_t *off)
+{
+       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);
+
+       cptype = parse_cp_type(buf, count);
+       free_page((unsigned long) buf);
+
+       if (cptype == CT_NONE)
+               return -EINVAL;
+
+       err = lkdtm_register_cpoint(which);
+       if (err < 0)
+               return err;
+
+       *off += count;
+
+       return count;
+}
+
+/* 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);
+
+       n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
+       for (i = 0; i < ARRAY_SIZE(cp_type); i++)
+               n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
+       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;
+}
+
+
+static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_INT_HARDWARE_ENTRY, f, buf, count, off);
+}
+
+static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_INT_HW_IRQ_EN, f, buf, count, off);
+}
+
+static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_INT_TASKLET_ENTRY, f, buf, count, off);
+}
+
+static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_FS_DEVRW, f, buf, count, off);
+}
+
+static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_MEM_SWAPOUT, f, buf, count, off);
+}
+
+static ssize_t timeradd_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_TIMERADD, f, buf, count, off);
+}
+
+static ssize_t scsi_dispatch_cmd_entry(struct file *f,
+               const char __user *buf, size_t count, loff_t *off)
+{
+       return do_register_entry(CN_SCSI_DISPATCH_CMD, f, buf, count, off);
+}
+
+static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
+               size_t count, loff_t *off)
+{
+       return do_register_entry(CN_IDE_CORE_CP, f, buf, count, off);
+}
+
+/* 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)
+{
+       enum ctype type;
+       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);
+
+       type = parse_cp_type(buf, count);
+       free_page((unsigned long) buf);
+       if (type == CT_NONE)
+               return -EINVAL;
+
+       printk(KERN_INFO "lkdtm: Performing direct entry %s\n",
+                       cp_type_to_str(type));
+       lkdtm_do_action(type);
+       *off += count;
+
+       return count;
+}
+
+struct crash_entry {
+       const char *name;
+       const struct file_operations fops;
+};
+
+static const struct crash_entry crash_entries[] = {
+       {"DIRECT", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = direct_entry} },
+       {"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = int_hardware_entry} },
+       {"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = int_hw_irq_en} },
+       {"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = int_tasklet_entry} },
+       {"FS_DEVRW", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = fs_devrw_entry} },
+       {"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = mem_swapout_entry} },
+       {"TIMERADD", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = timeradd_entry} },
+       {"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = scsi_dispatch_cmd_entry} },
+       {"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
+                       .llseek = generic_file_llseek,
+                       .open = lkdtm_debugfs_open,
+                       .write = ide_core_cp_entry} },
+};
+
+static struct dentry *lkdtm_debugfs_root;
+
+static int __init lkdtm_module_init(void)
+{
+       int ret = -EINVAL;
+       int n_debugfs_entries = 1; /* Assume only the direct entry */
+       int i;
+
+       /* Register debugfs interface */
+       lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
+       if (!lkdtm_debugfs_root) {
+               printk(KERN_ERR "lkdtm: creating root dir failed\n");
+               return -ENODEV;
+       }
+
+#ifdef CONFIG_KPROBES
+       n_debugfs_entries = ARRAY_SIZE(crash_entries);
+#endif
+
+       for (i = 0; i < n_debugfs_entries; i++) {
+               const struct crash_entry *cur = &crash_entries[i];
+               struct dentry *de;
+
+               de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
+                               NULL, &cur->fops);
+               if (de == NULL) {
+                       printk(KERN_ERR "lkdtm: could not create %s\n",
+                                       cur->name);
+                       goto out_err;
+               }
+       }
+
+       if (lkdtm_parse_commandline() == -EINVAL) {
+               printk(KERN_INFO "lkdtm: Invalid command\n");
+               goto out_err;
+       }
+
+       if (cpoint != CN_INVALID && cptype != CT_NONE) {
+               ret = lkdtm_register_cpoint(cpoint);
+               if (ret < 0) {
+                       printk(KERN_INFO "lkdtm: Invalid crash point %d\n",
+                                       cpoint);
+                       goto out_err;
+               }
+               printk(KERN_INFO "lkdtm: Crash point %s of type %s registered\n",
+                               cpoint_name, cpoint_type);
+       } else {
+               printk(KERN_INFO "lkdtm: No crash points registered, enable through debugfs\n");
        }
 
-       printk(KERN_INFO "lkdtm : Crash point %s of type %s registered\n",
-                                               cpoint_name, cpoint_type);
        return 0;
+
+out_err:
+       debugfs_remove_recursive(lkdtm_debugfs_root);
+       return ret;
 }
 
-void lkdtm_module_exit(void)
+static void __exit lkdtm_module_exit(void)
 {
-        unregister_jprobe(&lkdtm);
-        printk(KERN_INFO "lkdtm : Crash point unregistered\n");
+       debugfs_remove_recursive(lkdtm_debugfs_root);
+
+       unregister_jprobe(&lkdtm);
+       printk(KERN_INFO "lkdtm: Crash point unregistered\n");
 }
 
 module_init(lkdtm_module_init);