linux/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>
*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#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: {
volatile u32 data[8];
volatile u32 *p = data;
p[12] = 0x12345678;
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");