diff options
Diffstat (limited to 'drivers/misc/lkdtm_core.c')
| -rw-r--r-- | drivers/misc/lkdtm_core.c | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c new file mode 100644 index 000000000000..f9154b8d67f6 --- /dev/null +++ b/drivers/misc/lkdtm_core.c @@ -0,0 +1,544 @@ +/* + * Linux Kernel Dump Test Module for testing kernel crashes conditions: + * induces system failures at predefined crashpoints and under predefined + * operational conditions in order to evaluate the reliability of kernel + * sanity checking and crash dumps obtained using different dumping + * solutions. + * + * 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 <[email protected]> + * + * 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 <[email protected]> + * + * See Documentation/fault-injection/provoke-crashes.txt for instructions + */ +#include "lkdtm.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 + +static int lkdtm_debugfs_open(struct inode *inode, struct file *file); +static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf, + size_t count, loff_t *off); +static ssize_t direct_entry(struct file *f, const char __user *user_buf, + size_t count, loff_t *off); + +#ifdef CONFIG_KPROBES +static void lkdtm_handler(void); +static ssize_t lkdtm_debugfs_entry(struct file *f, + const char __user *user_buf, + size_t count, loff_t *off); + + +/* jprobe entry point handlers. */ +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 +static 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 +#endif + +/* Crash points */ +struct crashpoint { + const char *name; + const struct file_operations fops; + struct jprobe jprobe; +}; + +#define CRASHPOINT(_name, _write, _symbol, _entry) \ + { \ + .name = _name, \ + .fops = { \ + .read = lkdtm_debugfs_read, \ + .llseek = generic_file_llseek, \ + .open = lkdtm_debugfs_open, \ + .write = _write, \ + }, \ + .jprobe = { \ + .kp.symbol_name = _symbol, \ + .entry = (kprobe_opcode_t *)_entry, \ + }, \ + } + +/* Define the possible places where we can trigger a crash point. */ +struct crashpoint crashpoints[] = { + CRASHPOINT("DIRECT", direct_entry, + NULL, NULL), +#ifdef CONFIG_KPROBES + CRASHPOINT("INT_HARDWARE_ENTRY", lkdtm_debugfs_entry, + "do_IRQ", jp_do_irq), + CRASHPOINT("INT_HW_IRQ_EN", lkdtm_debugfs_entry, + "handle_IRQ_event", jp_handle_irq_event), + CRASHPOINT("INT_TASKLET_ENTRY", lkdtm_debugfs_entry, + "tasklet_action", jp_tasklet_action), + CRASHPOINT("FS_DEVRW", lkdtm_debugfs_entry, + "ll_rw_block", jp_ll_rw_block), + CRASHPOINT("MEM_SWAPOUT", lkdtm_debugfs_entry, + "shrink_inactive_list", jp_shrink_inactive_list), + CRASHPOINT("TIMERADD", lkdtm_debugfs_entry, + "hrtimer_start", jp_hrtimer_start), + CRASHPOINT("SCSI_DISPATCH_CMD", lkdtm_debugfs_entry, + "scsi_dispatch_cmd", jp_scsi_dispatch_cmd), +# ifdef CONFIG_IDE + CRASHPOINT("IDE_CORE_CP", lkdtm_debugfs_entry, + "generic_ide_ioctl", jp_generic_ide_ioctl), +# endif +#endif +}; + + +/* Crash types. */ +struct crashtype { + const char *name; + void (*func)(void); +}; + +#define CRASHTYPE(_name) \ + { \ + .name = __stringify(_name), \ + .func = lkdtm_ ## _name, \ + } + +/* Define the possible types of crashes that can be triggered. */ +struct crashtype crashtypes[] = { + CRASHTYPE(PANIC), + CRASHTYPE(BUG), + CRASHTYPE(WARNING), + CRASHTYPE(EXCEPTION), + CRASHTYPE(LOOP), + CRASHTYPE(OVERFLOW), + CRASHTYPE(CORRUPT_STACK), + CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE), + CRASHTYPE(OVERWRITE_ALLOCATION), + CRASHTYPE(WRITE_AFTER_FREE), + CRASHTYPE(READ_AFTER_FREE), + CRASHTYPE(WRITE_BUDDY_AFTER_FREE), + CRASHTYPE(READ_BUDDY_AFTER_FREE), + CRASHTYPE(SOFTLOCKUP), + CRASHTYPE(HARDLOCKUP), + CRASHTYPE(SPINLOCKUP), + CRASHTYPE(HUNG_TASK), + CRASHTYPE(EXEC_DATA), + CRASHTYPE(EXEC_STACK), + CRASHTYPE(EXEC_KMALLOC), + CRASHTYPE(EXEC_VMALLOC), + CRASHTYPE(EXEC_RODATA), + CRASHTYPE(EXEC_USERSPACE), + CRASHTYPE(ACCESS_USERSPACE), + CRASHTYPE(WRITE_RO), + CRASHTYPE(WRITE_RO_AFTER_INIT), + CRASHTYPE(WRITE_KERN), + CRASHTYPE(ATOMIC_UNDERFLOW), + CRASHTYPE(ATOMIC_OVERFLOW), + CRASHTYPE(USERCOPY_HEAP_SIZE_TO), + CRASHTYPE(USERCOPY_HEAP_SIZE_FROM), + CRASHTYPE(USERCOPY_HEAP_FLAG_TO), + CRASHTYPE(USERCOPY_HEAP_FLAG_FROM), + CRASHTYPE(USERCOPY_STACK_FRAME_TO), + CRASHTYPE(USERCOPY_STACK_FRAME_FROM), + CRASHTYPE(USERCOPY_STACK_BEYOND), + CRASHTYPE(USERCOPY_KERNEL), +}; + + +/* Global jprobe entry and crashtype. */ +static struct jprobe *lkdtm_jprobe; +struct crashpoint *lkdtm_crashpoint; +struct crashtype *lkdtm_crashtype; + +/* Module parameters */ +static int recur_count = -1; +module_param(recur_count, int, 0644); +MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test"); + +static char* cpoint_name; +module_param(cpoint_name, charp, 0444); +MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed"); + +static char* cpoint_type; +module_param(cpoint_type, charp, 0444); +MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\ + "hitting the crash point"); + +static int cpoint_count = DEFAULT_COUNT; +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"); + + +/* Return the crashtype number or NULL if the name is invalid */ +static struct crashtype *find_crashtype(const char *name) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(crashtypes); i++) { + if (!strcmp(name, crashtypes[i].name)) + return &crashtypes[i]; + } + + return NULL; +} + +/* + * This is forced noinline just so it distinctly shows up in the stackdump + * which makes validation of expected lkdtm crashes easier. + */ +static noinline void lkdtm_do_action(struct crashtype *crashtype) +{ + BUG_ON(!crashtype || !crashtype->func); + crashtype->func(); +} + +static int lkdtm_register_cpoint(struct crashpoint *crashpoint, + struct crashtype *crashtype) +{ + int ret; + + /* If this doesn't have a symbol, just call immediately. */ + if (!crashpoint->jprobe.kp.symbol_name) { + lkdtm_do_action(crashtype); + return 0; + } + + if (lkdtm_jprobe != NULL) + unregister_jprobe(lkdtm_jprobe); + + lkdtm_crashpoint = crashpoint; + lkdtm_crashtype = crashtype; + lkdtm_jprobe = &crashpoint->jprobe; + ret = register_jprobe(lkdtm_jprobe); + if (ret < 0) { + pr_info("Couldn't register jprobe %s\n", + crashpoint->jprobe.kp.symbol_name); + lkdtm_jprobe = NULL; + lkdtm_crashpoint = NULL; + lkdtm_crashtype = NULL; + } + + return ret; +} + +#ifdef CONFIG_KPROBES +/* Global crash counter and spinlock. */ +static int crash_count = DEFAULT_COUNT; +static DEFINE_SPINLOCK(crash_count_lock); + +/* Called by jprobe entry points. */ +static void lkdtm_handler(void) +{ + unsigned long flags; + bool do_it = false; + + BUG_ON(!lkdtm_crashpoint || !lkdtm_crashtype); + + spin_lock_irqsave(&crash_count_lock, flags); + crash_count--; + pr_info("Crash point %s of type %s hit, trigger in %d rounds\n", + lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count); + + if (crash_count == 0) { + do_it = true; + crash_count = cpoint_count; + } + spin_unlock_irqrestore(&crash_count_lock, flags); + + if (do_it) + lkdtm_do_action(lkdtm_crashtype); +} + +static ssize_t lkdtm_debugfs_entry(struct file *f, + const char __user *user_buf, + size_t count, loff_t *off) +{ + struct crashpoint *crashpoint = file_inode(f)->i_private; + struct crashtype *crashtype = NULL; + 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); + + crashtype = find_crashtype(buf); + free_page((unsigned long)buf); + + if (!crashtype) + return -EINVAL; + + err = lkdtm_register_cpoint(crashpoint, crashtype); + if (err < 0) + return err; + + *off += count; + + return count; +} +#endif + +/* 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(crashtypes); i++) { + n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", + crashtypes[i].name); + } + 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; +} + +/* 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) +{ + struct crashtype *crashtype; + 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); + + crashtype = find_crashtype(buf); + free_page((unsigned long) buf); + if (!crashtype) + return -EINVAL; + + pr_info("Performing direct entry %s\n", crashtype->name); + lkdtm_do_action(crashtype); + *off += count; + + return count; +} + +static struct dentry *lkdtm_debugfs_root; + +static int __init lkdtm_module_init(void) +{ + struct crashpoint *crashpoint = NULL; + struct crashtype *crashtype = NULL; + int ret = -EINVAL; + int i; + + /* Neither or both of these need to be set */ + if ((cpoint_type || cpoint_name) && !(cpoint_type && cpoint_name)) { + pr_err("Need both cpoint_type and cpoint_name or neither\n"); + return -EINVAL; + } + + if (cpoint_type) { + crashtype = find_crashtype(cpoint_type); + if (!crashtype) { + pr_err("Unknown crashtype '%s'\n", cpoint_type); + return -EINVAL; + } + } + + if (cpoint_name) { + for (i = 0; i < ARRAY_SIZE(crashpoints); i++) { + if (!strcmp(cpoint_name, crashpoints[i].name)) + crashpoint = &crashpoints[i]; + } + + /* Refuse unknown crashpoints. */ + if (!crashpoint) { + pr_err("Invalid crashpoint %s\n", cpoint_name); + return -EINVAL; + } + } + +#ifdef CONFIG_KPROBES + /* Set crash count. */ + crash_count = cpoint_count; +#endif + + /* Handle test-specific initialization. */ + lkdtm_bugs_init(&recur_count); + lkdtm_perms_init(); + lkdtm_usercopy_init(); + + /* Register debugfs interface */ + lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL); + if (!lkdtm_debugfs_root) { + pr_err("creating root dir failed\n"); + return -ENODEV; + } + + /* Install debugfs trigger files. */ + for (i = 0; i < ARRAY_SIZE(crashpoints); i++) { + struct crashpoint *cur = &crashpoints[i]; + struct dentry *de; + + de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root, + cur, &cur->fops); + if (de == NULL) { + pr_err("could not create crashpoint %s\n", cur->name); + goto out_err; + } + } + + /* Install crashpoint if one was selected. */ + if (crashpoint) { + ret = lkdtm_register_cpoint(crashpoint, crashtype); + if (ret < 0) { + pr_info("Invalid crashpoint %s\n", crashpoint->name); + goto out_err; + } + pr_info("Crash point %s of type %s registered\n", + crashpoint->name, cpoint_type); + } else { + pr_info("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); + + /* Handle test-specific clean-up. */ + lkdtm_usercopy_exit(); + + unregister_jprobe(lkdtm_jprobe); + pr_info("Crash point unregistered\n"); +} + +module_init(lkdtm_module_init); +module_exit(lkdtm_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Kernel crash testing module"); |