| /* |
| * 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> |
| * |
| * Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net> |
| * |
| * See Documentation/fault-injection/provoke-crashes.txt for instructions |
| */ |
| |
| #include <linux/kernel.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 |
| #define REC_NUM_DEFAULT 10 |
| |
| enum cname { |
| 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 { |
| 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[] = { |
| "INT_HARDWARE_ENTRY", |
| "INT_HW_IRQ_EN", |
| "INT_TASKLET_ENTRY", |
| "FS_DEVRW", |
| "MEM_SWAPOUT", |
| "TIMERADD", |
| "SCSI_DISPATCH_CMD", |
| "IDE_CORE_CP", |
| "DIRECT", |
| }; |
| |
| static char* cp_type[] = { |
| "PANIC", |
| "BUG", |
| "EXCEPTION", |
| "LOOP", |
| "OVERFLOW", |
| "CORRUPT_STACK", |
| "UNALIGNED_LOAD_STORE_WRITE", |
| "OVERWRITE_ALLOCATION", |
| "WRITE_AFTER_FREE", |
| "SOFTLOCKUP", |
| "HARDLOCKUP", |
| "HUNG_TASK", |
| }; |
| |
| static struct jprobe lkdtm; |
| |
| static int lkdtm_parse_commandline(void); |
| static void lkdtm_handler(void); |
| |
| 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 = 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, 0444); |
| MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed"); |
| 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"); |
| |
| 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 |
| 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 |
| |
| /* 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_count < 1 || recur_count < 1) |
| return -EINVAL; |
| |
| 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; |
| return 0; |
| } |
| } |
| |
| /* Could not find a valid crash point */ |
| return -EINVAL; |
| } |
| |
| 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); |
| } |
| |
| 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: { |
| /* Make sure the compiler creates and uses an 8 char array. */ |
| volatile char data[8]; |
| |
| memset((void *)data, 0, 64); |
| 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) |
| { |
| 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) { |
| do_it = true; |
| count = cpoint_count; |
| } |
| spin_unlock_irqrestore(&count_lock, flags); |
| |
| if (do_it) |
| lkdtm_do_action(cptype); |
| } |
| |
| static int lkdtm_register_cpoint(enum cname which) |
| { |
| int ret; |
| |
| cpoint = CN_INVALID; |
| if (lkdtm.entry != NULL) |
| unregister_jprobe(&lkdtm); |
| |
| 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 CN_INT_HW_IRQ_EN: |
| lkdtm.kp.symbol_name = "handle_IRQ_event"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event; |
| break; |
| case CN_INT_TASKLET_ENTRY: |
| lkdtm.kp.symbol_name = "tasklet_action"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action; |
| break; |
| case CN_FS_DEVRW: |
| lkdtm.kp.symbol_name = "ll_rw_block"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block; |
| break; |
| case CN_MEM_SWAPOUT: |
| lkdtm.kp.symbol_name = "shrink_inactive_list"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list; |
| break; |
| case CN_TIMERADD: |
| lkdtm.kp.symbol_name = "hrtimer_start"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start; |
| break; |
| case CN_SCSI_DISPATCH_CMD: |
| lkdtm.kp.symbol_name = "scsi_dispatch_cmd"; |
| lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd; |
| break; |
| 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"); |
| return -EINVAL; |
| #endif |
| break; |
| default: |
| 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"); |
| 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); |
| if (buf == NULL) |
| return -ENOMEM; |
| |
| 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"); |
| } |
| |
| 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); |
| |
| unregister_jprobe(&lkdtm); |
| printk(KERN_INFO "lkdtm: Crash point unregistered\n"); |
| } |
| |
| module_init(lkdtm_module_init); |
| module_exit(lkdtm_module_exit); |
| |
| MODULE_LICENSE("GPL"); |