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authorKees Cook <keescook@chromium.org>2016-02-22 14:05:44 -0800
committerKees Cook <keescook@chromium.org>2016-06-10 15:57:48 -0700
commit9e197e2f894c0270ffabd314d73c7730b09ac63c (patch)
tree5f5b14a533d9b472121152d796a7dc856a9f7372 /drivers/misc/lkdtm_core.c
parent3d0f0b6a5520878305589411b8d434fe088e4f21 (diff)
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lkdtm: split build into multiple source files
Kbuild lacks a way to do in-place objcopy or other modifications of built targets, so in order to move functions into non-text sections without renaming the kernel module, the build of lkdtm must be split into separate source files. This renames lkdtm.c to lkdtm_core.c in preparation for adding the source file for the .rodata section. Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'drivers/misc/lkdtm_core.c')
-rw-r--r--drivers/misc/lkdtm_core.c1023
1 files changed, 1023 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
new file mode 100644
index 000000000000..0a5cbbe12452
--- /dev/null
+++ b/drivers/misc/lkdtm_core.c
@@ -0,0 +1,1023 @@
+/*
+ * 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");