diff options
Diffstat (limited to 'drivers/misc/lkdtm.c')
| -rw-r--r-- | drivers/misc/lkdtm.c | 1023 |
1 files changed, 0 insertions, 1023 deletions
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c deleted file mode 100644 index 0a5cbbe12..000000000 --- a/drivers/misc/lkdtm.c +++ /dev/null @@ -1,1023 +0,0 @@ -/* - * 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 - */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#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> -#include <linux/vmalloc.h> -#include <linux/mman.h> -#include <asm/cacheflush.h> - -#ifdef CONFIG_IDE -#include <linux/ide.h> -#endif - -/* - * Make sure our attempts to over run the kernel stack doesn't trigger - * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we - * recurse past the end of THREAD_SIZE by default. - */ -#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0) -#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2) -#else -#define REC_STACK_SIZE (THREAD_SIZE / 8) -#endif -#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2) - -#define DEFAULT_COUNT 10 -#define EXEC_SIZE 64 - -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_WARNING, - CT_EXCEPTION, - CT_LOOP, - CT_OVERFLOW, - CT_CORRUPT_STACK, - CT_UNALIGNED_LOAD_STORE_WRITE, - CT_OVERWRITE_ALLOCATION, - CT_WRITE_AFTER_FREE, - CT_READ_AFTER_FREE, - CT_WRITE_BUDDY_AFTER_FREE, - CT_READ_BUDDY_AFTER_FREE, - CT_SOFTLOCKUP, - CT_HARDLOCKUP, - CT_SPINLOCKUP, - CT_HUNG_TASK, - CT_EXEC_DATA, - CT_EXEC_STACK, - CT_EXEC_KMALLOC, - CT_EXEC_VMALLOC, - CT_EXEC_USERSPACE, - CT_ACCESS_USERSPACE, - CT_WRITE_RO, - CT_WRITE_RO_AFTER_INIT, - CT_WRITE_KERN, - CT_WRAP_ATOMIC -}; - -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", - "WARNING", - "EXCEPTION", - "LOOP", - "OVERFLOW", - "CORRUPT_STACK", - "UNALIGNED_LOAD_STORE_WRITE", - "OVERWRITE_ALLOCATION", - "WRITE_AFTER_FREE", - "READ_AFTER_FREE", - "WRITE_BUDDY_AFTER_FREE", - "READ_BUDDY_AFTER_FREE", - "SOFTLOCKUP", - "HARDLOCKUP", - "SPINLOCKUP", - "HUNG_TASK", - "EXEC_DATA", - "EXEC_STACK", - "EXEC_KMALLOC", - "EXEC_VMALLOC", - "EXEC_USERSPACE", - "ACCESS_USERSPACE", - "WRITE_RO", - "WRITE_RO_AFTER_INIT", - "WRITE_KERN", - "WRAP_ATOMIC" -}; - -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); -static DEFINE_SPINLOCK(lock_me_up); - -static u8 data_area[EXEC_SIZE]; - -static const unsigned long rodata = 0xAA55AA55; -static unsigned long ro_after_init __ro_after_init = 0x55AA5500; - -module_param(recur_count, int, 0644); -MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test"); -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 -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 - -/* 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 remaining) -{ - char buf[REC_STACK_SIZE]; - - /* Make sure compiler does not optimize this away. */ - memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE); - if (!remaining) - return 0; - else - return recursive_loop(remaining - 1); -} - -static void do_nothing(void) -{ - return; -} - -/* Must immediately follow do_nothing for size calculuations to work out. */ -static void do_overwritten(void) -{ - pr_info("do_overwritten wasn't overwritten!\n"); - return; -} - -static noinline void corrupt_stack(void) -{ - /* Use default char array length that triggers stack protection. */ - char data[8]; - - memset((void *)data, 0, 64); -} - -static void noinline execute_location(void *dst) -{ - void (*func)(void) = dst; - - pr_info("attempting ok execution at %p\n", do_nothing); - do_nothing(); - - memcpy(dst, do_nothing, EXEC_SIZE); - flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE); - pr_info("attempting bad execution at %p\n", func); - func(); -} - -static void execute_user_location(void *dst) -{ - /* Intentionally crossing kernel/user memory boundary. */ - void (*func)(void) = dst; - - pr_info("attempting ok execution at %p\n", do_nothing); - do_nothing(); - - if (copy_to_user((void __user *)dst, do_nothing, EXEC_SIZE)) - return; - flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE); - pr_info("attempting bad execution at %p\n", func); - func(); -} - -static void lkdtm_do_action(enum ctype which) -{ - switch (which) { - case CT_PANIC: - panic("dumptest"); - break; - case CT_BUG: - BUG(); - break; - case CT_WARNING: - WARN_ON(1); - break; - case CT_EXCEPTION: - *((int *) 0) = 0; - break; - case CT_LOOP: - for (;;) - ; - break; - case CT_OVERFLOW: - (void) recursive_loop(recur_count); - break; - case CT_CORRUPT_STACK: - corrupt_stack(); - 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: { - int *base, *again; - size_t len = 1024; - /* - * The slub allocator uses the first word to store the free - * pointer in some configurations. Use the middle of the - * allocation to avoid running into the freelist - */ - size_t offset = (len / sizeof(*base)) / 2; - - base = kmalloc(len, GFP_KERNEL); - pr_info("Allocated memory %p-%p\n", base, &base[offset * 2]); - pr_info("Attempting bad write to freed memory at %p\n", - &base[offset]); - kfree(base); - base[offset] = 0x0abcdef0; - /* Attempt to notice the overwrite. */ - again = kmalloc(len, GFP_KERNEL); - kfree(again); - if (again != base) - pr_info("Hmm, didn't get the same memory range.\n"); - - break; - } - case CT_READ_AFTER_FREE: { - int *base, *val, saw; - size_t len = 1024; - /* - * The slub allocator uses the first word to store the free - * pointer in some configurations. Use the middle of the - * allocation to avoid running into the freelist - */ - size_t offset = (len / sizeof(*base)) / 2; - - base = kmalloc(len, GFP_KERNEL); - if (!base) - break; - - val = kmalloc(len, GFP_KERNEL); - if (!val) { - kfree(base); - break; - } - - *val = 0x12345678; - base[offset] = *val; - pr_info("Value in memory before free: %x\n", base[offset]); - - kfree(base); - - pr_info("Attempting bad read from freed memory\n"); - saw = base[offset]; - if (saw != *val) { - /* Good! Poisoning happened, so declare a win. */ - pr_info("Memory correctly poisoned (%x)\n", saw); - BUG(); - } - pr_info("Memory was not poisoned\n"); - - kfree(val); - break; - } - case CT_WRITE_BUDDY_AFTER_FREE: { - unsigned long p = __get_free_page(GFP_KERNEL); - if (!p) - break; - pr_info("Writing to the buddy page before free\n"); - memset((void *)p, 0x3, PAGE_SIZE); - free_page(p); - schedule(); - pr_info("Attempting bad write to the buddy page after free\n"); - memset((void *)p, 0x78, PAGE_SIZE); - /* Attempt to notice the overwrite. */ - p = __get_free_page(GFP_KERNEL); - free_page(p); - schedule(); - - break; - } - case CT_READ_BUDDY_AFTER_FREE: { - unsigned long p = __get_free_page(GFP_KERNEL); - int saw, *val; - int *base; - - if (!p) - break; - - val = kmalloc(1024, GFP_KERNEL); - if (!val) { - free_page(p); - break; - } - - base = (int *)p; - - *val = 0x12345678; - base[0] = *val; - pr_info("Value in memory before free: %x\n", base[0]); - free_page(p); - pr_info("Attempting to read from freed memory\n"); - saw = base[0]; - if (saw != *val) { - /* Good! Poisoning happened, so declare a win. */ - pr_info("Memory correctly poisoned (%x)\n", saw); - BUG(); - } - pr_info("Buddy page was not poisoned\n"); - - kfree(val); - break; - } - case CT_SOFTLOCKUP: - preempt_disable(); - for (;;) - cpu_relax(); - break; - case CT_HARDLOCKUP: - local_irq_disable(); - for (;;) - cpu_relax(); - break; - case CT_SPINLOCKUP: - /* Must be called twice to trigger. */ - spin_lock(&lock_me_up); - /* Let sparse know we intended to exit holding the lock. */ - __release(&lock_me_up); - break; - case CT_HUNG_TASK: - set_current_state(TASK_UNINTERRUPTIBLE); - schedule(); - break; - case CT_EXEC_DATA: - execute_location(data_area); - break; - case CT_EXEC_STACK: { - u8 stack_area[EXEC_SIZE]; - execute_location(stack_area); - break; - } - case CT_EXEC_KMALLOC: { - u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL); - execute_location(kmalloc_area); - kfree(kmalloc_area); - break; - } - case CT_EXEC_VMALLOC: { - u32 *vmalloc_area = vmalloc(EXEC_SIZE); - execute_location(vmalloc_area); - vfree(vmalloc_area); - break; - } - case CT_EXEC_USERSPACE: { - unsigned long user_addr; - - user_addr = vm_mmap(NULL, 0, PAGE_SIZE, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_ANONYMOUS | MAP_PRIVATE, 0); - if (user_addr >= TASK_SIZE) { - pr_warn("Failed to allocate user memory\n"); - return; - } - execute_user_location((void *)user_addr); - vm_munmap(user_addr, PAGE_SIZE); - break; - } - case CT_ACCESS_USERSPACE: { - unsigned long user_addr, tmp = 0; - unsigned long *ptr; - - user_addr = vm_mmap(NULL, 0, PAGE_SIZE, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_ANONYMOUS | MAP_PRIVATE, 0); - if (user_addr >= TASK_SIZE) { - pr_warn("Failed to allocate user memory\n"); - return; - } - - if (copy_to_user((void __user *)user_addr, &tmp, sizeof(tmp))) { - pr_warn("copy_to_user failed\n"); - vm_munmap(user_addr, PAGE_SIZE); - return; - } - - ptr = (unsigned long *)user_addr; - - pr_info("attempting bad read at %p\n", ptr); - tmp = *ptr; - tmp += 0xc0dec0de; - - pr_info("attempting bad write at %p\n", ptr); - *ptr = tmp; - - vm_munmap(user_addr, PAGE_SIZE); - - break; - } - case CT_WRITE_RO: { - /* Explicitly cast away "const" for the test. */ - unsigned long *ptr = (unsigned long *)&rodata; - - pr_info("attempting bad rodata write at %p\n", ptr); - *ptr ^= 0xabcd1234; - - break; - } - case CT_WRITE_RO_AFTER_INIT: { - unsigned long *ptr = &ro_after_init; - - /* - * Verify we were written to during init. Since an Oops - * is considered a "success", a failure is to just skip the - * real test. - */ - if ((*ptr & 0xAA) != 0xAA) { - pr_info("%p was NOT written during init!?\n", ptr); - break; - } - - pr_info("attempting bad ro_after_init write at %p\n", ptr); - *ptr ^= 0xabcd1234; - - break; - } - case CT_WRITE_KERN: { - size_t size; - unsigned char *ptr; - - size = (unsigned long)do_overwritten - - (unsigned long)do_nothing; - ptr = (unsigned char *)do_overwritten; - - pr_info("attempting bad %zu byte write at %p\n", size, ptr); - memcpy(ptr, (unsigned char *)do_nothing, size); - flush_icache_range((unsigned long)ptr, - (unsigned long)(ptr + size)); - - do_overwritten(); - break; - } - case CT_WRAP_ATOMIC: { - atomic_t under = ATOMIC_INIT(INT_MIN); - atomic_t over = ATOMIC_INIT(INT_MAX); - - pr_info("attempting atomic underflow\n"); - atomic_dec(&under); - pr_info("attempting atomic overflow\n"); - atomic_inc(&over); - - return; - } - case CT_NONE: - default: - break; - } - -} - -static void lkdtm_handler(void) -{ - unsigned long flags; - bool do_it = false; - - spin_lock_irqsave(&count_lock, flags); - count--; - pr_info("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 - pr_info("Crash point not available\n"); - return -EINVAL; -#endif - break; - default: - pr_info("Invalid Crash Point\n"); - return -EINVAL; - } - - cpoint = which; - if ((ret = register_jprobe(&lkdtm)) < 0) { - pr_info("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; - - pr_info("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; - - /* Make sure we can write to __ro_after_init values during __init */ - ro_after_init |= 0xAA; - - /* 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; - } - -#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) { - pr_err("could not create %s\n", cur->name); - goto out_err; - } - } - - if (lkdtm_parse_commandline() == -EINVAL) { - pr_info("Invalid command\n"); - goto out_err; - } - - if (cpoint != CN_INVALID && cptype != CT_NONE) { - ret = lkdtm_register_cpoint(cpoint); - if (ret < 0) { - pr_info("Invalid crash point %d\n", cpoint); - goto out_err; - } - pr_info("Crash point %s of type %s registered\n", - cpoint_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); - - unregister_jprobe(&lkdtm); - pr_info("Crash point unregistered\n"); -} - -module_init(lkdtm_module_init); -module_exit(lkdtm_module_exit); - -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("Kprobe module for testing crash dumps"); |