Merge tag 'lkdtm-next' of...

Merge tag 'lkdtm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into char-misc-testing

Kees writes:

refactoring for multiple source files and better layout

drivers/misc/Makefile

@@ -59,7 +59,11 @@ obj-$(CONFIG_CXL_BASE)		+= cxl/
 obj-$(CONFIG_PANEL)             += panel.o
 
 lkdtm-$(CONFIG_LKDTM)		+= lkdtm_core.o
+lkdtm-$(CONFIG_LKDTM)		+= lkdtm_bugs.o
+lkdtm-$(CONFIG_LKDTM)		+= lkdtm_heap.o
+lkdtm-$(CONFIG_LKDTM)		+= lkdtm_perms.o
 lkdtm-$(CONFIG_LKDTM)		+= lkdtm_rodata_objcopy.o
+lkdtm-$(CONFIG_LKDTM)		+= lkdtm_usercopy.o
 
 OBJCOPYFLAGS :=
 OBJCOPYFLAGS_lkdtm_rodata_objcopy.o := \

drivers/misc/lkdtm.h

 #ifndef __LKDTM_H
 #define __LKDTM_H
 
+/* lkdtm_bugs.c */
+void __init lkdtm_bugs_init(int *recur_param);
+void lkdtm_PANIC(void);
+void lkdtm_BUG(void);
+void lkdtm_WARNING(void);
+void lkdtm_EXCEPTION(void);
+void lkdtm_LOOP(void);
+void lkdtm_OVERFLOW(void);
+void lkdtm_CORRUPT_STACK(void);
+void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void);
+void lkdtm_SOFTLOCKUP(void);
+void lkdtm_HARDLOCKUP(void);
+void lkdtm_SPINLOCKUP(void);
+void lkdtm_HUNG_TASK(void);
+void lkdtm_ATOMIC_UNDERFLOW(void);
+void lkdtm_ATOMIC_OVERFLOW(void);
+
+/* lkdtm_heap.c */
+void lkdtm_OVERWRITE_ALLOCATION(void);
+void lkdtm_WRITE_AFTER_FREE(void);
+void lkdtm_READ_AFTER_FREE(void);
+void lkdtm_WRITE_BUDDY_AFTER_FREE(void);
+void lkdtm_READ_BUDDY_AFTER_FREE(void);
+
+/* lkdtm_perms.c */
+void __init lkdtm_perms_init(void);
+void lkdtm_WRITE_RO(void);
+void lkdtm_WRITE_RO_AFTER_INIT(void);
+void lkdtm_WRITE_KERN(void);
+void lkdtm_EXEC_DATA(void);
+void lkdtm_EXEC_STACK(void);
+void lkdtm_EXEC_KMALLOC(void);
+void lkdtm_EXEC_VMALLOC(void);
+void lkdtm_EXEC_RODATA(void);
+void lkdtm_EXEC_USERSPACE(void);
+void lkdtm_ACCESS_USERSPACE(void);
+
+/* lkdtm_rodata.c */
 void lkdtm_rodata_do_nothing(void);
 
+/* lkdtm_usercopy.c */
+void __init lkdtm_usercopy_init(void);
+void __exit lkdtm_usercopy_exit(void);
+void lkdtm_USERCOPY_HEAP_SIZE_TO(void);
+void lkdtm_USERCOPY_HEAP_SIZE_FROM(void);
+void lkdtm_USERCOPY_HEAP_FLAG_TO(void);
+void lkdtm_USERCOPY_HEAP_FLAG_FROM(void);
+void lkdtm_USERCOPY_STACK_FRAME_TO(void);
+void lkdtm_USERCOPY_STACK_FRAME_FROM(void);
+void lkdtm_USERCOPY_STACK_BEYOND(void);
+void lkdtm_USERCOPY_KERNEL(void);
+
+
 #endif

drivers/misc/lkdtm_bugs.c

+/*
+ * This is for all the tests related to logic bugs (e.g. bad dereferences,
+ * bad alignment, bad loops, bad locking, bad scheduling, deep stacks, and
+ * lockups) along with other things that don't fit well into existing LKDTM
+ * test source files.
+ */
+#define pr_fmt(fmt) "lkdtm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+#include "lkdtm.h"
+
+/*
+ * 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)
+
+static int recur_count = REC_NUM_DEFAULT;
+
+static DEFINE_SPINLOCK(lock_me_up);
+
+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);
+}
+
+/* If the depth is negative, use the default, otherwise keep parameter. */
+void __init lkdtm_bugs_init(int *recur_param)
+{
+	if (*recur_param < 0)
+		*recur_param = recur_count;
+	else
+		recur_count = *recur_param;
+}
+
+void lkdtm_PANIC(void)
+{
+	panic("dumptest");
+}
+
+void lkdtm_BUG(void)
+{
+	BUG();
+}
+
+void lkdtm_WARNING(void)
+{
+	WARN_ON(1);
+}
+
+void lkdtm_EXCEPTION(void)
+{
+	*((int *) 0) = 0;
+}
+
+void lkdtm_LOOP(void)
+{
+	for (;;)
+		;
+}
+
+void lkdtm_OVERFLOW(void)
+{
+	(void) recursive_loop(recur_count);
+}
+
+noinline void lkdtm_CORRUPT_STACK(void)
+{
+	/* Use default char array length that triggers stack protection. */
+	char data[8];
+
+	memset((void *)data, 0, 64);
+}
+
+void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
+{
+	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;
+}
+
+void lkdtm_SOFTLOCKUP(void)
+{
+	preempt_disable();
+	for (;;)
+		cpu_relax();
+}
+
+void lkdtm_HARDLOCKUP(void)
+{
+	local_irq_disable();
+	for (;;)
+		cpu_relax();
+}
+
+void lkdtm_SPINLOCKUP(void)
+{
+	/* 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);
+}
+
+void lkdtm_HUNG_TASK(void)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule();
+}
+
+void lkdtm_ATOMIC_UNDERFLOW(void)
+{
+	atomic_t under = ATOMIC_INIT(INT_MIN);
+
+	pr_info("attempting good atomic increment\n");
+	atomic_inc(&under);
+	atomic_dec(&under);
+
+	pr_info("attempting bad atomic underflow\n");
+	atomic_dec(&under);
+}
+
+void lkdtm_ATOMIC_OVERFLOW(void)
+{
+	atomic_t over = ATOMIC_INIT(INT_MAX);
+
+	pr_info("attempting good atomic decrement\n");
+	atomic_dec(&over);
+	atomic_inc(&over);
+
+	pr_info("attempting bad atomic overflow\n");
+	atomic_inc(&over);
+}

drivers/misc/lkdtm_core.c

@@ -44,9 +44,6 @@
 #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>
@@ -54,164 +51,20 @@
 
 #include "lkdtm.h"
 
-/*
- * 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_RODATA,
-	CT_EXEC_USERSPACE,
-	CT_ACCESS_USERSPACE,
-	CT_WRITE_RO,
-	CT_WRITE_RO_AFTER_INIT,
-	CT_WRITE_KERN,
-	CT_ATOMIC_UNDERFLOW,
-	CT_ATOMIC_OVERFLOW,
-	CT_USERCOPY_HEAP_SIZE_TO,
-	CT_USERCOPY_HEAP_SIZE_FROM,
-	CT_USERCOPY_HEAP_FLAG_TO,
-	CT_USERCOPY_HEAP_FLAG_FROM,
-	CT_USERCOPY_STACK_FRAME_TO,
-	CT_USERCOPY_STACK_FRAME_FROM,
-	CT_USERCOPY_STACK_BEYOND,
-};
-
-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_RODATA",
-	"EXEC_USERSPACE",
-	"ACCESS_USERSPACE",
-	"WRITE_RO",
-	"WRITE_RO_AFTER_INIT",
-	"WRITE_KERN",
-	"ATOMIC_UNDERFLOW",
-	"ATOMIC_OVERFLOW",
-	"USERCOPY_HEAP_SIZE_TO",
-	"USERCOPY_HEAP_SIZE_FROM",
-	"USERCOPY_HEAP_FLAG_TO",
-	"USERCOPY_HEAP_FLAG_FROM",
-	"USERCOPY_STACK_FRAME_TO",
-	"USERCOPY_STACK_FRAME_FROM",
-	"USERCOPY_STACK_BEYOND",
-};
-
-static struct jprobe lkdtm;
-
-static int lkdtm_parse_commandline(void);
 static void lkdtm_handler(void);
+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);
+static ssize_t lkdtm_debugfs_entry(struct file *f,
+				   const char __user *user_buf,
+				   size_t count, loff_t *off);
 
-static char* cpoint_name;
-static char* cpoint_type;
-static int cpoint_count = DEFAULT_COUNT;
-static int recur_count = REC_NUM_DEFAULT;
-static int alloc_size = 1024;
-static size_t cache_size;
-
-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 struct kmem_cache *bad_cache;
-
-static const unsigned char test_text[] = "This is a test.\n";
-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");
-module_param(alloc_size, int, 0644);
-MODULE_PARM_DESC(alloc_size, " Size of allocation for user copy tests "\
-			     "(from 1 to PAGE_SIZE)");
 
+/* jprobe entry point handlers. */
 static unsigned int jp_do_irq(unsigned int irq)
 {
 	lkdtm_handler();
@@ -276,780 +129,220 @@ static int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
 }
 #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;
-}
+/* Crash points */
+struct crashpoint {
+	const char *name;
+	const struct file_operations fops;
+	struct jprobe jprobe;
+};
 
-static noinline void corrupt_stack(void)
-{
-	/* Use default char array length that triggers stack protection. */
-	char data[8];
+#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
+};
 
-	memset((void *)data, 0, 64);
-}
 
-static noinline void execute_location(void *dst, bool write)
-{
-	void (*func)(void) = dst;
+/* Crash types. */
+struct crashtype {
+	const char *name;
+	void (*func)(void);
+};
 
-	pr_info("attempting ok execution at %p\n", do_nothing);
-	do_nothing();
+#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),
+};
 
-	if (write) {
-		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;
+/* Global jprobe entry and crashtype. */
+static struct jprobe *lkdtm_jprobe;
+struct crashpoint *lkdtm_crashpoint;
+struct crashtype *lkdtm_crashtype;
 
-	pr_info("attempting ok execution at %p\n", do_nothing);
-	do_nothing();
+/* Global crash counter and spinlock. */
+static int crash_count = DEFAULT_COUNT;
+static DEFINE_SPINLOCK(crash_count_lock);
 
-	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();
-}
+/* 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");
 
-/*
- * Instead of adding -Wno-return-local-addr, just pass the stack address
- * through a function to obfuscate it from the compiler.
- */
-static noinline unsigned char *trick_compiler(unsigned char *stack)
-{
-	return stack + 0;
-}
+static char* cpoint_name;
+module_param(cpoint_name, charp, 0444);
+MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
 
-static noinline unsigned char *do_usercopy_stack_callee(int value)
-{
-	unsigned char buf[32];
-	int i;
+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");
 
-	/* Exercise stack to avoid everything living in registers. */
-	for (i = 0; i < sizeof(buf); i++) {
-		buf[i] = value & 0xff;
-	}
+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 trick_compiler(buf);
-}
 
-static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
+/* Return the crashtype number or NULL if the name is invalid */
+static struct crashtype *find_crashtype(const char *name)
 {
-	unsigned long user_addr;
-	unsigned char good_stack[32];
-	unsigned char *bad_stack;
 	int i;
 
-	/* Exercise stack to avoid everything living in registers. */
-	for (i = 0; i < sizeof(good_stack); i++)
-		good_stack[i] = test_text[i % sizeof(test_text)];
-
-	/* This is a pointer to outside our current stack frame. */
-	if (bad_frame) {
-		bad_stack = do_usercopy_stack_callee(alloc_size);
-	} else {
-		/* Put start address just inside stack. */
-		bad_stack = task_stack_page(current) + THREAD_SIZE;
-		bad_stack -= sizeof(unsigned long);
-	}
-
-	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 (to_user) {
-		pr_info("attempting good copy_to_user of local stack\n");
-		if (copy_to_user((void __user *)user_addr, good_stack,
-				 sizeof(good_stack))) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user of distant stack\n");
-		if (copy_to_user((void __user *)user_addr, bad_stack,
-				 sizeof(good_stack))) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		/*
-		 * There isn't a safe way to not be protected by usercopy
-		 * if we're going to write to another thread's stack.
-		 */
-		if (!bad_frame)
-			goto free_user;
-
-		pr_info("attempting good copy_from_user of local stack\n");
-		if (copy_from_user(good_stack, (void __user *)user_addr,
-				   sizeof(good_stack))) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_from_user of distant stack\n");
-		if (copy_from_user(bad_stack, (void __user *)user_addr,
-				   sizeof(good_stack))) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-}
-
-static void do_usercopy_heap_size(bool to_user)
-{
-	unsigned long user_addr;
-	unsigned char *one, *two;
-	size_t size = clamp_t(int, alloc_size, 1, PAGE_SIZE);
-
-	one = kmalloc(size, GFP_KERNEL);
-	two = kmalloc(size, GFP_KERNEL);
-	if (!one || !two) {
-		pr_warn("Failed to allocate kernel memory\n");
-		goto free_kernel;
-	}
-
-	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");
-		goto free_kernel;
-	}
-
-	memset(one, 'A', size);
-	memset(two, 'B', size);
-
-	if (to_user) {
-		pr_info("attempting good copy_to_user of correct size\n");
-		if (copy_to_user((void __user *)user_addr, one, size)) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user of too large size\n");
-		if (copy_to_user((void __user *)user_addr, one, 2 * size)) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		pr_info("attempting good copy_from_user of correct size\n");
-		if (copy_from_user(one, (void __user *)user_addr,
-				   size)) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
+	for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
+		if (!strcmp(name, crashtypes[i].name))
+			return &crashtypes[i];
 	}
 
-		pr_info("attempting bad copy_from_user of too large size\n");
-		if (copy_from_user(one, (void __user *)user_addr, 2 * size)) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-free_kernel:
-	kfree(one);
-	kfree(two);
+	return NULL;
 }
 
-static void do_usercopy_heap_flag(bool to_user)
-{
-	unsigned long user_addr;
-	unsigned char *good_buf = NULL;
-	unsigned char *bad_buf = NULL;
-
-	/* Make sure cache was prepared. */
-	if (!bad_cache) {
-		pr_warn("Failed to allocate kernel cache\n");
-		return;
-	}
-
-	/*
-	 * Allocate one buffer from each cache (kmalloc will have the
-	 * SLAB_USERCOPY flag already, but "bad_cache" won't).
+/*
+ * This is forced noinline just so it distinctly shows up in the stackdump
+ * which makes validation of expected lkdtm crashes easier.
  */
-	good_buf = kmalloc(cache_size, GFP_KERNEL);
-	bad_buf = kmem_cache_alloc(bad_cache, GFP_KERNEL);
-	if (!good_buf || !bad_buf) {
-		pr_warn("Failed to allocate buffers from caches\n");
-		goto free_alloc;
-	}
-
-	/* Allocate user memory we'll poke at. */
-	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");
-		goto free_alloc;
-	}
-
-	memset(good_buf, 'A', cache_size);
-	memset(bad_buf, 'B', cache_size);
-
-	if (to_user) {
-		pr_info("attempting good copy_to_user with SLAB_USERCOPY\n");
-		if (copy_to_user((void __user *)user_addr, good_buf,
-				 cache_size)) {
-			pr_warn("copy_to_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_to_user w/o SLAB_USERCOPY\n");
-		if (copy_to_user((void __user *)user_addr, bad_buf,
-				 cache_size)) {
-			pr_warn("copy_to_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	} else {
-		pr_info("attempting good copy_from_user with SLAB_USERCOPY\n");
-		if (copy_from_user(good_buf, (void __user *)user_addr,
-				   cache_size)) {
-			pr_warn("copy_from_user failed unexpectedly?!\n");
-			goto free_user;
-		}
-
-		pr_info("attempting bad copy_from_user w/o SLAB_USERCOPY\n");
-		if (copy_from_user(bad_buf, (void __user *)user_addr,
-				   cache_size)) {
-			pr_warn("copy_from_user failed, but lacked Oops\n");
-			goto free_user;
-		}
-	}
-
-free_user:
-	vm_munmap(user_addr, PAGE_SIZE);
-free_alloc:
-	if (bad_buf)
-		kmem_cache_free(bad_cache, bad_buf);
-	kfree(good_buf);
-}
-
-static void lkdtm_do_action(enum ctype which)
+static noinline void lkdtm_do_action(struct crashtype *crashtype)
 {
-	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, true);
-		break;
-	case CT_EXEC_STACK: {
-		u8 stack_area[EXEC_SIZE];
-		execute_location(stack_area, true);
-		break;
-	}
-	case CT_EXEC_KMALLOC: {
-		u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
-		execute_location(kmalloc_area, true);
-		kfree(kmalloc_area);
-		break;
-	}
-	case CT_EXEC_VMALLOC: {
-		u32 *vmalloc_area = vmalloc(EXEC_SIZE);
-		execute_location(vmalloc_area, true);
-		vfree(vmalloc_area);
-		break;
-	}
-	case CT_EXEC_RODATA:
-		execute_location(lkdtm_rodata_do_nothing, false);
-		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_ATOMIC_UNDERFLOW: {
-		atomic_t under = ATOMIC_INIT(INT_MIN);
-
-		pr_info("attempting good atomic increment\n");
-		atomic_inc(&under);
-		atomic_dec(&under);
-
-		pr_info("attempting bad atomic underflow\n");
-		atomic_dec(&under);
-		break;
-	}
-	case CT_ATOMIC_OVERFLOW: {
-		atomic_t over = ATOMIC_INIT(INT_MAX);
-
-		pr_info("attempting good atomic decrement\n");
-		atomic_dec(&over);
-		atomic_inc(&over);
-
-		pr_info("attempting bad atomic overflow\n");
-		atomic_inc(&over);
-
-		return;
-	}
-	case CT_USERCOPY_HEAP_SIZE_TO:
-		do_usercopy_heap_size(true);
-		break;
-	case CT_USERCOPY_HEAP_SIZE_FROM:
-		do_usercopy_heap_size(false);
-		break;
-	case CT_USERCOPY_HEAP_FLAG_TO:
-		do_usercopy_heap_flag(true);
-		break;
-	case CT_USERCOPY_HEAP_FLAG_FROM:
-		do_usercopy_heap_flag(false);
-		break;
-	case CT_USERCOPY_STACK_FRAME_TO:
-		do_usercopy_stack(true, true);
-		break;
-	case CT_USERCOPY_STACK_FRAME_FROM:
-		do_usercopy_stack(false, true);
-		break;
-	case CT_USERCOPY_STACK_BEYOND:
-		do_usercopy_stack(true, false);
-		break;
-	case CT_NONE:
-	default:
-		break;
-	}
-
+	BUG_ON(!crashtype || !crashtype->func);
+	crashtype->func();
 }
 
+/* Called by jprobe entry points. */
 static void lkdtm_handler(void)
 {
 	unsigned long flags;
 	bool do_it = false;
 
-	spin_lock_irqsave(&count_lock, flags);
-	count--;
+	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",
-		cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
+		lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);
 
-	if (count == 0) {
+	if (crash_count == 0) {
 		do_it = true;
-		count = cpoint_count;
+		crash_count = cpoint_count;
 	}
-	spin_unlock_irqrestore(&count_lock, flags);
+	spin_unlock_irqrestore(&crash_count_lock, flags);
 
 	if (do_it)
-		lkdtm_do_action(cptype);
+		lkdtm_do_action(lkdtm_crashtype);
 }
 
-static int lkdtm_register_cpoint(enum cname which)
+static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
+				 struct crashtype *crashtype)
 {
 	int ret;
 
-	cpoint = CN_INVALID;
-	if (lkdtm.entry != NULL)
-		unregister_jprobe(&lkdtm);
-
-	switch (which) {
-	case CN_DIRECT:
-		lkdtm_do_action(cptype);
+	/* If this doesn't have a symbol, just call immediately. */
+	if (!crashpoint->jprobe.kp.symbol_name) {
+		lkdtm_do_action(crashtype);
 		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;
+	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;
 }
 
-static ssize_t do_register_entry(enum cname which, struct file *f,
-		const char __user *user_buf, size_t count, loff_t *off)
+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;
 
@@ -1067,13 +360,13 @@ static ssize_t do_register_entry(enum cname which, struct file *f,
 	buf[count] = '\0';
 	strim(buf);
 
-	cptype = parse_cp_type(buf, count);
-	free_page((unsigned long) buf);
+	crashtype = find_crashtype(buf);
+	free_page((unsigned long)buf);
 
-	if (cptype == CT_NONE)
+	if (!crashtype)
 		return -EINVAL;
 
-	err = lkdtm_register_cpoint(which);
+	err = lkdtm_register_cpoint(crashpoint, crashtype);
 	if (err < 0)
 		return err;
 
@@ -1094,8 +387,10 @@ static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
 		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]);
+	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,
@@ -1110,60 +405,11 @@ 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;
+	struct crashtype *crashtype;
 	char *buf;
 
 	if (count >= PAGE_SIZE)
@@ -1182,77 +428,61 @@ static ssize_t direct_entry(struct file *f, const char __user *user_buf,
 	buf[count] = '\0';
 	strim(buf);
 
-	type = parse_cp_type(buf, count);
+	crashtype = find_crashtype(buf);
 	free_page((unsigned long) buf);
-	if (type == CT_NONE)
+	if (!crashtype)
 		return -EINVAL;
 
-	pr_info("Performing direct entry %s\n", cp_type_to_str(type));
-	lkdtm_do_action(type);
+	pr_info("Performing direct entry %s\n", crashtype->name);
+	lkdtm_do_action(crashtype);
 	*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)
 {
+	struct crashpoint *crashpoint = NULL;
+	struct crashtype *crashtype = NULL;
 	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;
+	/* 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;
+		}
+	}
+
+	/* Set crash count. */
+	crash_count = cpoint_count;
 
-	/* Prepare cache that lacks SLAB_USERCOPY flag. */
-	cache_size = clamp_t(int, alloc_size, 1, PAGE_SIZE);
-	bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0,
-				      0, NULL);
+	/* 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);
@@ -1261,35 +491,28 @@ static int __init lkdtm_module_init(void)
 		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];
+	/* 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,
-				NULL, &cur->fops);
+					 cur, &cur->fops);
 		if (de == NULL) {
-			pr_err("could not create %s\n", cur->name);
+			pr_err("could not create crashpoint %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);
+	/* Install crashpoint if one was selected. */
+	if (crashpoint) {
+		ret = lkdtm_register_cpoint(crashpoint, crashtype);
 		if (ret < 0) {
-			pr_info("Invalid crash point %d\n", cpoint);
+			pr_info("Invalid crashpoint %s\n", crashpoint->name);
 			goto out_err;
 		}
 		pr_info("Crash point %s of type %s registered\n",
-			cpoint_name, cpoint_type);
+			crashpoint->name, cpoint_type);
 	} else {
 		pr_info("No crash points registered, enable through debugfs\n");
 	}
@@ -1305,9 +528,10 @@ static void __exit lkdtm_module_exit(void)
 {
 	debugfs_remove_recursive(lkdtm_debugfs_root);
 
-	kmem_cache_destroy(bad_cache);
+	/* Handle test-specific clean-up. */
+	lkdtm_usercopy_exit();
 
-	unregister_jprobe(&lkdtm);
+	unregister_jprobe(lkdtm_jprobe);
 	pr_info("Crash point unregistered\n");
 }
 
@@ -1315,4 +539,4 @@ module_init(lkdtm_module_init);
 module_exit(lkdtm_module_exit);
 
 MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Kprobe module for testing crash dumps");
+MODULE_DESCRIPTION("Kernel crash testing module");

drivers/misc/lkdtm_heap.c

+/*
+ * This is for all the tests relating directly to heap memory, including
+ * page allocation and slab allocations.
+ */
+#define pr_fmt(fmt) "lkdtm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "lkdtm.h"
+
+/*
+ * This tries to stay within the next largest power-of-2 kmalloc cache
+ * to avoid actually overwriting anything important if it's not detected
+ * correctly.
+ */
+void lkdtm_OVERWRITE_ALLOCATION(void)
+{
+	size_t len = 1020;
+	u32 *data = kmalloc(len, GFP_KERNEL);
+
+	data[1024 / sizeof(u32)] = 0x12345678;
+	kfree(data);
+}
+
+void lkdtm_WRITE_AFTER_FREE(void)
+{
+	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");
+}
+
+void lkdtm_READ_AFTER_FREE(void)
+{
+	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) {
+		pr_info("Unable to allocate base memory.\n");
+		return;
+	}
+
+	val = kmalloc(len, GFP_KERNEL);
+	if (!val) {
+		pr_info("Unable to allocate val memory.\n");
+		kfree(base);
+		return;
+	}
+
+	*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);
+}
+
+void lkdtm_WRITE_BUDDY_AFTER_FREE(void)
+{
+	unsigned long p = __get_free_page(GFP_KERNEL);
+	if (!p) {
+		pr_info("Unable to allocate free page\n");
+		return;
+	}
+
+	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();
+}
+
+void lkdtm_READ_BUDDY_AFTER_FREE(void)
+{
+	unsigned long p = __get_free_page(GFP_KERNEL);
+	int saw, *val;
+	int *base;
+
+	if (!p) {
+		pr_info("Unable to allocate free page\n");
+		return;
+	}
+
+	val = kmalloc(1024, GFP_KERNEL);
+	if (!val) {
+		pr_info("Unable to allocate val memory.\n");
+		free_page(p);
+		return;
+	}
+
+	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);
+}

drivers/misc/lkdtm_perms.c

+/*
+ * This is for all the tests related to validating kernel memory
+ * permissions: non-executable regions, non-writable regions, and
+ * even non-readable regions.
+ */
+#define pr_fmt(fmt) "lkdtm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mman.h>
+#include <linux/uaccess.h>
+#include <asm/cacheflush.h>
+
+#include "lkdtm.h"
+
+/* Whether or not to fill the target memory area with do_nothing(). */
+#define CODE_WRITE	true
+#define CODE_AS_IS	false
+
+/* How many bytes to copy to be sure we've copied enough of do_nothing(). */
+#define EXEC_SIZE 64
+
+/* This is non-const, so it will end up in the .data section. */
+static u8 data_area[EXEC_SIZE];
+
+/* This is cost, so it will end up in the .rodata section. */
+static const unsigned long rodata = 0xAA55AA55;
+
+/* This is marked __ro_after_init, so it should ultimately be .rodata. */
+static unsigned long ro_after_init __ro_after_init = 0x55AA5500;
+
+/*
+ * This just returns to the caller. It is designed to be copied into
+ * non-executable memory regions.
+ */
+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 execute_location(void *dst, bool write)
+{
+	void (*func)(void) = dst;
+
+	pr_info("attempting ok execution at %p\n", do_nothing);
+	do_nothing();
+
+	if (write == CODE_WRITE) {
+		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();
+}
+
+void lkdtm_WRITE_RO(void)
+{
+	/* 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;
+}
+
+void lkdtm_WRITE_RO_AFTER_INIT(void)
+{
+	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);
+		return;
+	}
+
+	pr_info("attempting bad ro_after_init write at %p\n", ptr);
+	*ptr ^= 0xabcd1234;
+}
+
+void lkdtm_WRITE_KERN(void)
+{
+	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();
+}
+
+void lkdtm_EXEC_DATA(void)
+{
+	execute_location(data_area, CODE_WRITE);
+}
+
+void lkdtm_EXEC_STACK(void)
+{
+	u8 stack_area[EXEC_SIZE];
+	execute_location(stack_area, CODE_WRITE);
+}
+
+void lkdtm_EXEC_KMALLOC(void)
+{
+	u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
+	execute_location(kmalloc_area, CODE_WRITE);
+	kfree(kmalloc_area);
+}
+
+void lkdtm_EXEC_VMALLOC(void)
+{
+	u32 *vmalloc_area = vmalloc(EXEC_SIZE);
+	execute_location(vmalloc_area, CODE_WRITE);
+	vfree(vmalloc_area);
+}
+
+void lkdtm_EXEC_RODATA(void)
+{
+	execute_location(lkdtm_rodata_do_nothing, CODE_AS_IS);
+}
+
+void lkdtm_EXEC_USERSPACE(void)
+{
+	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);
+}
+
+void lkdtm_ACCESS_USERSPACE(void)
+{
+	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);
+}
+
+void __init lkdtm_perms_init(void)
+{
+	/* Make sure we can write to __ro_after_init values during __init */
+	ro_after_init |= 0xAA;
+
+}

drivers/misc/lkdtm_usercopy.c

+/*
+ * This is for all the tests related to copy_to_user() and copy_from_user()
+ * hardening.
+ */
+#define pr_fmt(fmt) "lkdtm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mman.h>
+#include <linux/uaccess.h>
+#include <asm/cacheflush.h>
+
+static size_t cache_size = 1024;
+static struct kmem_cache *bad_cache;
+
+static const unsigned char test_text[] = "This is a test.\n";
+
+/*
+ * Instead of adding -Wno-return-local-addr, just pass the stack address
+ * through a function to obfuscate it from the compiler.
+ */
+static noinline unsigned char *trick_compiler(unsigned char *stack)
+{
+	return stack + 0;
+}
+
+static noinline unsigned char *do_usercopy_stack_callee(int value)
+{
+	unsigned char buf[32];
+	int i;
+
+	/* Exercise stack to avoid everything living in registers. */
+	for (i = 0; i < sizeof(buf); i++) {
+		buf[i] = value & 0xff;
+	}
+
+	return trick_compiler(buf);
+}
+
+static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
+{
+	unsigned long user_addr;
+	unsigned char good_stack[32];
+	unsigned char *bad_stack;
+	int i;
+
+	/* Exercise stack to avoid everything living in registers. */
+	for (i = 0; i < sizeof(good_stack); i++)
+		good_stack[i] = test_text[i % sizeof(test_text)];
+
+	/* This is a pointer to outside our current stack frame. */
+	if (bad_frame) {
+		bad_stack = do_usercopy_stack_callee((uintptr_t)bad_stack);
+	} else {
+		/* Put start address just inside stack. */
+		bad_stack = task_stack_page(current) + THREAD_SIZE;
+		bad_stack -= sizeof(unsigned long);
+	}
+
+	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 (to_user) {
+		pr_info("attempting good copy_to_user of local stack\n");
+		if (copy_to_user((void __user *)user_addr, good_stack,
+				 sizeof(good_stack))) {
+			pr_warn("copy_to_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_to_user of distant stack\n");
+		if (copy_to_user((void __user *)user_addr, bad_stack,
+				 sizeof(good_stack))) {
+			pr_warn("copy_to_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	} else {
+		/*
+		 * There isn't a safe way to not be protected by usercopy
+		 * if we're going to write to another thread's stack.
+		 */
+		if (!bad_frame)
+			goto free_user;
+
+		pr_info("attempting good copy_from_user of local stack\n");
+		if (copy_from_user(good_stack, (void __user *)user_addr,
+				   sizeof(good_stack))) {
+			pr_warn("copy_from_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_from_user of distant stack\n");
+		if (copy_from_user(bad_stack, (void __user *)user_addr,
+				   sizeof(good_stack))) {
+			pr_warn("copy_from_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	}
+
+free_user:
+	vm_munmap(user_addr, PAGE_SIZE);
+}
+
+static void do_usercopy_heap_size(bool to_user)
+{
+	unsigned long user_addr;
+	unsigned char *one, *two;
+	const size_t size = 1024;
+
+	one = kmalloc(size, GFP_KERNEL);
+	two = kmalloc(size, GFP_KERNEL);
+	if (!one || !two) {
+		pr_warn("Failed to allocate kernel memory\n");
+		goto free_kernel;
+	}
+
+	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");
+		goto free_kernel;
+	}
+
+	memset(one, 'A', size);
+	memset(two, 'B', size);
+
+	if (to_user) {
+		pr_info("attempting good copy_to_user of correct size\n");
+		if (copy_to_user((void __user *)user_addr, one, size)) {
+			pr_warn("copy_to_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_to_user of too large size\n");
+		if (copy_to_user((void __user *)user_addr, one, 2 * size)) {
+			pr_warn("copy_to_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	} else {
+		pr_info("attempting good copy_from_user of correct size\n");
+		if (copy_from_user(one, (void __user *)user_addr, size)) {
+			pr_warn("copy_from_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_from_user of too large size\n");
+		if (copy_from_user(one, (void __user *)user_addr, 2 * size)) {
+			pr_warn("copy_from_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	}
+
+free_user:
+	vm_munmap(user_addr, PAGE_SIZE);
+free_kernel:
+	kfree(one);
+	kfree(two);
+}
+
+static void do_usercopy_heap_flag(bool to_user)
+{
+	unsigned long user_addr;
+	unsigned char *good_buf = NULL;
+	unsigned char *bad_buf = NULL;
+
+	/* Make sure cache was prepared. */
+	if (!bad_cache) {
+		pr_warn("Failed to allocate kernel cache\n");
+		return;
+	}
+
+	/*
+	 * Allocate one buffer from each cache (kmalloc will have the
+	 * SLAB_USERCOPY flag already, but "bad_cache" won't).
+	 */
+	good_buf = kmalloc(cache_size, GFP_KERNEL);
+	bad_buf = kmem_cache_alloc(bad_cache, GFP_KERNEL);
+	if (!good_buf || !bad_buf) {
+		pr_warn("Failed to allocate buffers from caches\n");
+		goto free_alloc;
+	}
+
+	/* Allocate user memory we'll poke at. */
+	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");
+		goto free_alloc;
+	}
+
+	memset(good_buf, 'A', cache_size);
+	memset(bad_buf, 'B', cache_size);
+
+	if (to_user) {
+		pr_info("attempting good copy_to_user with SLAB_USERCOPY\n");
+		if (copy_to_user((void __user *)user_addr, good_buf,
+				 cache_size)) {
+			pr_warn("copy_to_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_to_user w/o SLAB_USERCOPY\n");
+		if (copy_to_user((void __user *)user_addr, bad_buf,
+				 cache_size)) {
+			pr_warn("copy_to_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	} else {
+		pr_info("attempting good copy_from_user with SLAB_USERCOPY\n");
+		if (copy_from_user(good_buf, (void __user *)user_addr,
+				   cache_size)) {
+			pr_warn("copy_from_user failed unexpectedly?!\n");
+			goto free_user;
+		}
+
+		pr_info("attempting bad copy_from_user w/o SLAB_USERCOPY\n");
+		if (copy_from_user(bad_buf, (void __user *)user_addr,
+				   cache_size)) {
+			pr_warn("copy_from_user failed, but lacked Oops\n");
+			goto free_user;
+		}
+	}
+
+free_user:
+	vm_munmap(user_addr, PAGE_SIZE);
+free_alloc:
+	if (bad_buf)
+		kmem_cache_free(bad_cache, bad_buf);
+	kfree(good_buf);
+}
+
+/* Callable tests. */
+void lkdtm_USERCOPY_HEAP_SIZE_TO(void)
+{
+	do_usercopy_heap_size(true);
+}
+
+void lkdtm_USERCOPY_HEAP_SIZE_FROM(void)
+{
+	do_usercopy_heap_size(false);
+}
+
+void lkdtm_USERCOPY_HEAP_FLAG_TO(void)
+{
+	do_usercopy_heap_flag(true);
+}
+
+void lkdtm_USERCOPY_HEAP_FLAG_FROM(void)
+{
+	do_usercopy_heap_flag(false);
+}
+
+void lkdtm_USERCOPY_STACK_FRAME_TO(void)
+{
+	do_usercopy_stack(true, true);
+}
+
+void lkdtm_USERCOPY_STACK_FRAME_FROM(void)
+{
+	do_usercopy_stack(false, true);
+}
+
+void lkdtm_USERCOPY_STACK_BEYOND(void)
+{
+	do_usercopy_stack(true, false);
+}
+
+void lkdtm_USERCOPY_KERNEL(void)
+{
+	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;
+	}
+
+	pr_info("attempting good copy_to_user from kernel rodata\n");
+	if (copy_to_user((void __user *)user_addr, test_text,
+			 sizeof(test_text))) {
+		pr_warn("copy_to_user failed unexpectedly?!\n");
+		goto free_user;
+	}
+
+	pr_info("attempting bad copy_to_user from kernel text\n");
+	if (copy_to_user((void __user *)user_addr, vm_mmap, PAGE_SIZE)) {
+		pr_warn("copy_to_user failed, but lacked Oops\n");
+		goto free_user;
+	}
+
+free_user:
+	vm_munmap(user_addr, PAGE_SIZE);
+}
+
+void __init lkdtm_usercopy_init(void)
+{
+	/* Prepare cache that lacks SLAB_USERCOPY flag. */
+	bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0,
+				      0, NULL);
+}
+
+void __exit lkdtm_usercopy_exit(void)
+{
+	kmem_cache_destroy(bad_cache);
+}