This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / misc / lkdtm.c
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
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+/*
+ * 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 = 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, " 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");
+
+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_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)
+{
+       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_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;
+}
+
+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");