linux/drivers/misc/lkdtm.c
Frederic Weisbecker a48223f944 lktdm: add support for hardlockup, softlockup and hung task crashes
This adds three new types of kernel "crashes" in the lkdtm driver to
trigger hardlockups, softlockups and task hung states at will.

The first two are useful to test the new generic lockup detector and check
its further regressions.  The latter one is a bonus to check the hung task
detector regressions even though it's not currently in rework.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:54 -07:00

675 lines
15 KiB
C

/*
* 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 {
INVALID,
INT_HARDWARE_ENTRY,
INT_HW_IRQ_EN,
INT_TASKLET_ENTRY,
FS_DEVRW,
MEM_SWAPOUT,
TIMERADD,
SCSI_DISPATCH_CMD,
IDE_CORE_CP,
DIRECT,
};
enum ctype {
NONE,
PANIC,
BUG,
EXCEPTION,
LOOP,
OVERFLOW,
CORRUPT_STACK,
UNALIGNED_LOAD_STORE_WRITE,
OVERWRITE_ALLOCATION,
WRITE_AFTER_FREE,
SOFTLOCKUP,
HARDLOCKUP,
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 = 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
/* 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 NONE;
}
static const char *cp_type_to_str(enum ctype type)
{
if (type == 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 == INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
return "INVALID";
return cp_name[name - 1];
}
static int lkdtm_parse_commandline(void)
{
int i;
if (cpoint_count < 1 || recur_count < 1)
return -EINVAL;
count = cpoint_count;
/* 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 == 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 PANIC:
panic("dumptest");
break;
case BUG:
BUG();
break;
case EXCEPTION:
*((int *) 0) = 0;
break;
case LOOP:
for (;;)
;
break;
case OVERFLOW:
(void) recursive_loop(0);
break;
case CORRUPT_STACK: {
volatile u32 data[8];
volatile u32 *p = data;
p[12] = 0x12345678;
break;
}
case 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 OVERWRITE_ALLOCATION: {
size_t len = 1020;
u32 *data = kmalloc(len, GFP_KERNEL);
data[1024 / sizeof(u32)] = 0x12345678;
kfree(data);
break;
}
case WRITE_AFTER_FREE: {
size_t len = 1024;
u32 *data = kmalloc(len, GFP_KERNEL);
kfree(data);
schedule();
memset(data, 0x78, len);
break;
}
case SOFTLOCKUP:
preempt_disable();
for (;;)
cpu_relax();
break;
case HARDLOCKUP:
local_irq_disable();
for (;;)
cpu_relax();
break;
case HUNG_TASK:
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
break;
case NONE:
default:
break;
}
}
static void lkdtm_handler(void)
{
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) {
lkdtm_do_action(cptype);
count = cpoint_count;
}
}
static int lkdtm_register_cpoint(enum cname which)
{
int ret;
cpoint = INVALID;
if (lkdtm.entry != NULL)
unregister_jprobe(&lkdtm);
switch (which) {
case DIRECT:
lkdtm_do_action(cptype);
return 0;
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");
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 = 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 == 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(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(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(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(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(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(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(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(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 == 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,
.open = lkdtm_debugfs_open,
.write = direct_entry} },
{"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = int_hardware_entry} },
{"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = int_hw_irq_en} },
{"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = int_tasklet_entry} },
{"FS_DEVRW", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = fs_devrw_entry} },
{"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = mem_swapout_entry} },
{"TIMERADD", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = timeradd_entry} },
{"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
.open = lkdtm_debugfs_open,
.write = scsi_dispatch_cmd_entry} },
{"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
.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 != INVALID && cptype != 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");