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authorKees Cook <keescook@chromium.org>2018-03-07 01:58:09 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-07 06:18:55 +0300
commit039a1c42058db54692a6d4497508bd48555f29fb (patch)
tree0fbd5a504e8a3cdf0cffd7e6bd0c41332f3e55d0 /drivers/misc/lkdtm/core.c
parent37b96a4931dba07cebbf07092e55d1562155412b (diff)
downloadlinux-039a1c42058db54692a6d4497508bd48555f29fb.tar.xz
lkdtm: Relocate code to subdirectory
The LKDTM modules keep expanding, and it's getting weird to have each file get a prefix. Instead, move to a subdirectory for cleaner handling. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/lkdtm/core.c')
-rw-r--r--drivers/misc/lkdtm/core.c505
1 files changed, 505 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
new file mode 100644
index 000000000000..2154d1bfd18b
--- /dev/null
+++ b/drivers/misc/lkdtm/core.c
@@ -0,0 +1,505 @@
+/*
+ * 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 <ankita@in.ibm.com>
+ *
+ * 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 "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 int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs);
+static ssize_t lkdtm_debugfs_entry(struct file *f,
+ const char __user *user_buf,
+ size_t count, loff_t *off);
+# define CRASHPOINT_KPROBE(_symbol) \
+ .kprobe = { \
+ .symbol_name = (_symbol), \
+ .pre_handler = lkdtm_kprobe_handler, \
+ },
+# define CRASHPOINT_WRITE(_symbol) \
+ (_symbol) ? lkdtm_debugfs_entry : direct_entry
+#else
+# define CRASHPOINT_KPROBE(_symbol)
+# define CRASHPOINT_WRITE(_symbol) direct_entry
+#endif
+
+/* Crash points */
+struct crashpoint {
+ const char *name;
+ const struct file_operations fops;
+ struct kprobe kprobe;
+};
+
+#define CRASHPOINT(_name, _symbol) \
+ { \
+ .name = _name, \
+ .fops = { \
+ .read = lkdtm_debugfs_read, \
+ .llseek = generic_file_llseek, \
+ .open = lkdtm_debugfs_open, \
+ .write = CRASHPOINT_WRITE(_symbol) \
+ }, \
+ CRASHPOINT_KPROBE(_symbol) \
+ }
+
+/* Define the possible places where we can trigger a crash point. */
+static struct crashpoint crashpoints[] = {
+ CRASHPOINT("DIRECT", NULL),
+#ifdef CONFIG_KPROBES
+ CRASHPOINT("INT_HARDWARE_ENTRY", "do_IRQ"),
+ CRASHPOINT("INT_HW_IRQ_EN", "handle_irq_event"),
+ CRASHPOINT("INT_TASKLET_ENTRY", "tasklet_action"),
+ CRASHPOINT("FS_DEVRW", "ll_rw_block"),
+ CRASHPOINT("MEM_SWAPOUT", "shrink_inactive_list"),
+ CRASHPOINT("TIMERADD", "hrtimer_start"),
+ CRASHPOINT("SCSI_DISPATCH_CMD", "scsi_dispatch_cmd"),
+# ifdef CONFIG_IDE
+ CRASHPOINT("IDE_CORE_CP", "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. */
+static const struct crashtype crashtypes[] = {
+ CRASHTYPE(PANIC),
+ CRASHTYPE(BUG),
+ CRASHTYPE(WARNING),
+ CRASHTYPE(EXCEPTION),
+ CRASHTYPE(LOOP),
+ CRASHTYPE(OVERFLOW),
+ CRASHTYPE(CORRUPT_LIST_ADD),
+ CRASHTYPE(CORRUPT_LIST_DEL),
+ CRASHTYPE(CORRUPT_USER_DS),
+ CRASHTYPE(CORRUPT_STACK),
+ CRASHTYPE(CORRUPT_STACK_STRONG),
+ CRASHTYPE(STACK_GUARD_PAGE_LEADING),
+ CRASHTYPE(STACK_GUARD_PAGE_TRAILING),
+ 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(REFCOUNT_INC_OVERFLOW),
+ CRASHTYPE(REFCOUNT_ADD_OVERFLOW),
+ CRASHTYPE(REFCOUNT_INC_NOT_ZERO_OVERFLOW),
+ CRASHTYPE(REFCOUNT_ADD_NOT_ZERO_OVERFLOW),
+ CRASHTYPE(REFCOUNT_DEC_ZERO),
+ CRASHTYPE(REFCOUNT_DEC_NEGATIVE),
+ CRASHTYPE(REFCOUNT_DEC_AND_TEST_NEGATIVE),
+ CRASHTYPE(REFCOUNT_SUB_AND_TEST_NEGATIVE),
+ CRASHTYPE(REFCOUNT_INC_ZERO),
+ CRASHTYPE(REFCOUNT_ADD_ZERO),
+ CRASHTYPE(REFCOUNT_INC_SATURATED),
+ CRASHTYPE(REFCOUNT_DEC_SATURATED),
+ CRASHTYPE(REFCOUNT_ADD_SATURATED),
+ CRASHTYPE(REFCOUNT_INC_NOT_ZERO_SATURATED),
+ CRASHTYPE(REFCOUNT_ADD_NOT_ZERO_SATURATED),
+ CRASHTYPE(REFCOUNT_DEC_AND_TEST_SATURATED),
+ CRASHTYPE(REFCOUNT_SUB_AND_TEST_SATURATED),
+ CRASHTYPE(REFCOUNT_TIMING),
+ CRASHTYPE(ATOMIC_TIMING),
+ CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
+ CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
+ CRASHTYPE(USERCOPY_HEAP_WHITELIST_TO),
+ CRASHTYPE(USERCOPY_HEAP_WHITELIST_FROM),
+ CRASHTYPE(USERCOPY_STACK_FRAME_TO),
+ CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
+ CRASHTYPE(USERCOPY_STACK_BEYOND),
+ CRASHTYPE(USERCOPY_KERNEL),
+};
+
+
+/* Global kprobe entry and crashtype. */
+static struct kprobe *lkdtm_kprobe;
+static struct crashpoint *lkdtm_crashpoint;
+static const 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 const 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(const struct crashtype *crashtype)
+{
+ if (WARN_ON(!crashtype || !crashtype->func))
+ return;
+ crashtype->func();
+}
+
+static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
+ const struct crashtype *crashtype)
+{
+ int ret;
+
+ /* If this doesn't have a symbol, just call immediately. */
+ if (!crashpoint->kprobe.symbol_name) {
+ lkdtm_do_action(crashtype);
+ return 0;
+ }
+
+ if (lkdtm_kprobe != NULL)
+ unregister_kprobe(lkdtm_kprobe);
+
+ lkdtm_crashpoint = crashpoint;
+ lkdtm_crashtype = crashtype;
+ lkdtm_kprobe = &crashpoint->kprobe;
+ ret = register_kprobe(lkdtm_kprobe);
+ if (ret < 0) {
+ pr_info("Couldn't register kprobe %s\n",
+ crashpoint->kprobe.symbol_name);
+ lkdtm_kprobe = 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 kprobe entry points. */
+static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
+{
+ unsigned long flags;
+ bool do_it = false;
+
+ if (WARN_ON(!lkdtm_crashpoint || !lkdtm_crashtype))
+ return 0;
+
+ 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);
+
+ return 0;
+}
+
+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;
+ const 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)
+{
+ const 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;
+ const 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();
+
+ if (lkdtm_kprobe != NULL)
+ unregister_kprobe(lkdtm_kprobe);
+
+ 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");