/* * 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/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 <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; 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 int count = DEFAULT_COUNT; 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_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed"); module_param(cpoint_type, charp, 0644); 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 static int lkdtm_parse_commandline(void) { int i; if (cpoint_name == NULL || cpoint_type == NULL || 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; } } static int __init 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_inactive_list"; lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_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; } static void __exit 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");