3 files changed, 358 insertions, 1 deletions

diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 19c2b85249c3..c1bf1fb04c5c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -3,5 +3,6 @@
 #
 obj- := misc.o  # Dummy rule to force built-in.o to be made
 
-obj-$(CONFIG_IBM_ASM)   += ibmasm/
+obj-$(CONFIG_IBM_ASM)           += ibmasm/
 obj-$(CONFIG_HDPU_FEATURES)     += hdpuftrs/
+obj-$(CONFIG_LKDTM)             += lkdtm.o
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
new file mode 100644
index 000000000000..e689ee94ac3d
--- /dev/null
+++ b/drivers/misc/lkdtm.c
@@ -0,0 +1,342 @@
+/*
+ * 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/module.h>
+#include <linux/kprobes.h>
+#include <linux/kallsyms.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.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, "Recurcion 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, 06444);
+MODULE_PARM_DESC(cpoint_type, "Crash Point Type, action to be taken on\
+                                hitting the crash point");
+module_param(cpoint_count, int, 06444);
+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, struct pt_regs *regs)
+{
+        lkdtm_handler();
+        jprobe_return();
+        return 0;
+}
+
+irqreturn_t jp_handle_irq_event(unsigned int irq, struct pt_regs *regs,
+                        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_page_list(struct list_head *page_list,
+                                        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_page_list";
+                lkdtm.entry = (kprobe_opcode_t*) jp_shrink_page_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");
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f9ae75cc0145..756a908c441d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -384,3 +384,17 @@ config RCU_TORTURE_TEST
           at boot time (you probably don't).
           Say M if you want the RCU torture tests to build as a module.
           Say N if you are unsure.
+
+config LKDTM
+        tristate "Linux Kernel Dump Test Tool Module"
+        depends on KPROBES
+        default n
+        help
+        This module enables testing of the different dumping mechanisms by
+        inducing system failures at predefined crash points.
+        If you don't need it: say N
+        Choose M here to compile this code as a module. The module will be
+        called lkdtm.
+
+        Documentation on how to use the module can be found in
+        drivers/misc/lkdtm.c