[thirdparty/linux.git] / lib / test_stackinit.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Test cases for compiler-based stack variable zeroing via future
 * compiler flags or CONFIG_GCC_PLUGIN_STRUCTLEAK*.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>

/* Exfiltration buffer. */
#define MAX_VAR_SIZE	128
static u8 check_buf[MAX_VAR_SIZE];

/* Character array to trigger stack protector in all functions. */
#define VAR_BUFFER	 32

/* Volatile mask to convince compiler to copy memory with 0xff. */
static volatile u8 forced_mask = 0xff;

/* Location and size tracking to validate fill and test are colocated. */
static void *fill_start, *target_start;
static size_t fill_size, target_size;

static bool range_contains(char *haystack_start, size_t haystack_size,
			   char *needle_start, size_t needle_size)
{
	if (needle_start >= haystack_start &&
	    needle_start + needle_size <= haystack_start + haystack_size)
		return true;
	return false;
}

#define DO_NOTHING_TYPE_SCALAR(var_type)	var_type
#define DO_NOTHING_TYPE_STRING(var_type)	void
#define DO_NOTHING_TYPE_STRUCT(var_type)	void

#define DO_NOTHING_RETURN_SCALAR(ptr)		*(ptr)
#define DO_NOTHING_RETURN_STRING(ptr)		/**/
#define DO_NOTHING_RETURN_STRUCT(ptr)		/**/

#define DO_NOTHING_CALL_SCALAR(var, name)			\
		(var) = do_nothing_ ## name(&(var))
#define DO_NOTHING_CALL_STRING(var, name)			\
		do_nothing_ ## name(var)
#define DO_NOTHING_CALL_STRUCT(var, name)			\
		do_nothing_ ## name(&(var))

#define FETCH_ARG_SCALAR(var)		&var
#define FETCH_ARG_STRING(var)		var
#define FETCH_ARG_STRUCT(var)		&var

#define FILL_SIZE_STRING		16

#define INIT_CLONE_SCALAR		/**/
#define INIT_CLONE_STRING		[FILL_SIZE_STRING]
#define INIT_CLONE_STRUCT		/**/

#define INIT_SCALAR_none		/**/
#define INIT_SCALAR_zero		= 0

#define INIT_STRING_none		[FILL_SIZE_STRING] /**/
#define INIT_STRING_zero		[FILL_SIZE_STRING] = { }

#define INIT_STRUCT_none		/**/
#define INIT_STRUCT_zero		= { }
#define INIT_STRUCT_static_partial	= { .two = 0, }
#define INIT_STRUCT_static_all		= { .one = arg->one,		\
					    .two = arg->two,		\
					    .three = arg->three,	\
					    .four = arg->four,		\
					}
#define INIT_STRUCT_dynamic_partial	= { .two = arg->two, }
#define INIT_STRUCT_dynamic_all		= { .one = arg->one,		\
					    .two = arg->two,		\
					    .three = arg->three,	\
					    .four = arg->four,		\
					}
#define INIT_STRUCT_runtime_partial	;				\
					var.two = 0
#define INIT_STRUCT_runtime_all		;				\
					var.one = 0;			\
					var.two = 0;			\
					var.three = 0;			\
					memset(&var.four, 0,		\
					       sizeof(var.four))

/*
 * @name: unique string name for the test
 * @var_type: type to be tested for zeroing initialization
 * @which: is this a SCALAR, STRING, or STRUCT type?
 * @init_level: what kind of initialization is performed
 */
#define DEFINE_TEST_DRIVER(name, var_type, which)		\
/* Returns 0 on success, 1 on failure. */			\
static noinline __init int test_ ## name (void)			\
{								\
	var_type zero INIT_CLONE_ ## which;			\
	int ignored;						\
	u8 sum = 0, i;						\
								\
	/* Notice when a new test is larger than expected. */	\
	BUILD_BUG_ON(sizeof(zero) > MAX_VAR_SIZE);		\
								\
	/* Fill clone type with zero for per-field init. */	\
	memset(&zero, 0x00, sizeof(zero));			\
	/* Clear entire check buffer for 0xFF overlap test. */	\
	memset(check_buf, 0x00, sizeof(check_buf));		\
	/* Fill stack with 0xFF. */				\
	ignored = leaf_ ##name((unsigned long)&ignored, 1,	\
				FETCH_ARG_ ## which(zero));	\
	/* Verify all bytes overwritten with 0xFF. */		\
	for (sum = 0, i = 0; i < target_size; i++)		\
		sum += (check_buf[i] != 0xFF);			\
	if (sum) {						\
		pr_err(#name ": leaf fill was not 0xFF!?\n");	\
		return 1;					\
	}							\
	/* Clear entire check buffer for later bit tests. */	\
	memset(check_buf, 0x00, sizeof(check_buf));		\
	/* Extract stack-defined variable contents. */		\
	ignored = leaf_ ##name((unsigned long)&ignored, 0,	\
				FETCH_ARG_ ## which(zero));	\
								\
	/* Validate that compiler lined up fill and target. */	\
	if (!range_contains(fill_start, fill_size,		\
			    target_start, target_size)) {	\
		pr_err(#name ": stack fill missed target!?\n");	\
		pr_err(#name ": fill %zu wide\n", fill_size);	\
		pr_err(#name ": target offset by %d\n",	\
			(int)((ssize_t)(uintptr_t)fill_start -	\
			(ssize_t)(uintptr_t)target_start));	\
		return 1;					\
	}							\
								\
	/* Look for any bytes still 0xFF in check region. */	\
	for (sum = 0, i = 0; i < target_size; i++)		\
		sum += (check_buf[i] == 0xFF);			\
								\
	if (sum == 0)						\
		pr_info(#name " ok\n");				\
	else							\
		pr_warn(#name " FAIL (uninit bytes: %d)\n",	\
			sum);					\
								\
	return (sum != 0);					\
}
#define DEFINE_TEST(name, var_type, which, init_level)		\
/* no-op to force compiler into ignoring "uninitialized" vars */\
static noinline __init DO_NOTHING_TYPE_ ## which(var_type)	\
do_nothing_ ## name(var_type *ptr)				\
{								\
	/* Will always be true, but compiler doesn't know. */	\
	if ((unsigned long)ptr > 0x2)				\
		return DO_NOTHING_RETURN_ ## which(ptr);	\
	else							\
		return DO_NOTHING_RETURN_ ## which(ptr + 1);	\
}								\
static noinline __init int leaf_ ## name(unsigned long sp,	\
					 bool fill,		\
					 var_type *arg)		\
{								\
	char buf[VAR_BUFFER];					\
	var_type var INIT_ ## which ## _ ## init_level;		\
								\
	target_start = &var;					\
	target_size = sizeof(var);				\
	/*							\
	 * Keep this buffer around to make sure we've got a	\
	 * stack frame of SOME kind...				\
	 */							\
	memset(buf, (char)(sp & 0xff), sizeof(buf));		\
	/* Fill variable with 0xFF. */				\
	if (fill) {						\
		fill_start = &var;				\
		fill_size = sizeof(var);			\
		memset(fill_start,				\
		       (char)((sp & 0xff) | forced_mask),	\
		       fill_size);				\
	}							\
								\
	/* Silence "never initialized" warnings. */		\
	DO_NOTHING_CALL_ ## which(var, name);			\
								\
	/* Exfiltrate "var". */					\
	memcpy(check_buf, target_start, target_size);		\
								\
	return (int)buf[0] | (int)buf[sizeof(buf) - 1];		\
}								\
DEFINE_TEST_DRIVER(name, var_type, which)

/* Structure with no padding. */
struct test_packed {
	unsigned long one;
	unsigned long two;
	unsigned long three;
	unsigned long four;
};

/* Simple structure with padding likely to be covered by compiler. */
struct test_small_hole {
	size_t one;
	char two;
	/* 3 byte padding hole here. */
	int three;
	unsigned long four;
};

/* Try to trigger unhandled padding in a structure. */
struct test_aligned {
	u32 internal1;
	u64 internal2;
} __aligned(64);

struct test_big_hole {
	u8 one;
	u8 two;
	u8 three;
	/* 61 byte padding hole here. */
	struct test_aligned four;
} __aligned(64);

struct test_trailing_hole {
	char *one;
	char *two;
	char *three;
	char four;
	/* "sizeof(unsigned long) - 1" byte padding hole here. */
};

/* Test if STRUCTLEAK is clearing structs with __user fields. */
struct test_user {
	u8 one;
	unsigned long two;
	char __user *three;
	unsigned long four;
};

#define DEFINE_SCALAR_TEST(name, init)				\
		DEFINE_TEST(name ## _ ## init, name, SCALAR, init)

#define DEFINE_SCALAR_TESTS(init)				\
		DEFINE_SCALAR_TEST(u8, init);			\
		DEFINE_SCALAR_TEST(u16, init);			\
		DEFINE_SCALAR_TEST(u32, init);			\
		DEFINE_SCALAR_TEST(u64, init);			\
		DEFINE_TEST(char_array_ ## init, unsigned char, STRING, init)

#define DEFINE_STRUCT_TEST(name, init)				\
		DEFINE_TEST(name ## _ ## init,			\
			    struct test_ ## name, STRUCT, init)

#define DEFINE_STRUCT_TESTS(init)				\
		DEFINE_STRUCT_TEST(small_hole, init);		\
		DEFINE_STRUCT_TEST(big_hole, init);		\
		DEFINE_STRUCT_TEST(trailing_hole, init);	\
		DEFINE_STRUCT_TEST(packed, init)

/* These should be fully initialized all the time! */
DEFINE_SCALAR_TESTS(zero);
DEFINE_STRUCT_TESTS(zero);
/* Static initialization: padding may be left uninitialized. */
DEFINE_STRUCT_TESTS(static_partial);
DEFINE_STRUCT_TESTS(static_all);
/* Dynamic initialization: padding may be left uninitialized. */
DEFINE_STRUCT_TESTS(dynamic_partial);
DEFINE_STRUCT_TESTS(dynamic_all);
/* Runtime initialization: padding may be left uninitialized. */
DEFINE_STRUCT_TESTS(runtime_partial);
DEFINE_STRUCT_TESTS(runtime_all);
/* No initialization without compiler instrumentation. */
DEFINE_SCALAR_TESTS(none);
DEFINE_STRUCT_TESTS(none);
DEFINE_TEST(user, struct test_user, STRUCT, none);

/*
 * Check two uses through a variable declaration outside either path,
 * which was noticed as a special case in porting earlier stack init
 * compiler logic.
 */
static int noinline __leaf_switch_none(int path, bool fill)
{
	switch (path) {
		uint64_t var;

	case 1:
		target_start = &var;
		target_size = sizeof(var);
		if (fill) {
			fill_start = &var;
			fill_size = sizeof(var);

			memset(fill_start, forced_mask | 0x55, fill_size);
		}
		memcpy(check_buf, target_start, target_size);
		break;
	case 2:
		target_start = &var;
		target_size = sizeof(var);
		if (fill) {
			fill_start = &var;
			fill_size = sizeof(var);

			memset(fill_start, forced_mask | 0xaa, fill_size);
		}
		memcpy(check_buf, target_start, target_size);
		break;
	default:
		var = 5;
		return var & forced_mask;
	}
	return 0;
}

static noinline __init int leaf_switch_1_none(unsigned long sp, bool fill,
					      uint64_t *arg)
{
	return __leaf_switch_none(1, fill);
}

static noinline __init int leaf_switch_2_none(unsigned long sp, bool fill,
					      uint64_t *arg)
{
	return __leaf_switch_none(2, fill);
}

DEFINE_TEST_DRIVER(switch_1_none, uint64_t, SCALAR);
DEFINE_TEST_DRIVER(switch_2_none, uint64_t, SCALAR);

static int __init test_stackinit_init(void)
{
	unsigned int failures = 0;

#define test_scalars(init)	do {				\
		failures += test_u8_ ## init ();		\
		failures += test_u16_ ## init ();		\
		failures += test_u32_ ## init ();		\
		failures += test_u64_ ## init ();		\
		failures += test_char_array_ ## init ();	\
	} while (0)

#define test_structs(init)	do {				\
		failures += test_small_hole_ ## init ();	\
		failures += test_big_hole_ ## init ();		\
		failures += test_trailing_hole_ ## init ();	\
		failures += test_packed_ ## init ();		\
	} while (0)

	/* These are explicitly initialized and should always pass. */
	test_scalars(zero);
	test_structs(zero);
	/* Padding here appears to be accidentally always initialized? */
	test_structs(dynamic_partial);
	/* Padding initialization depends on compiler behaviors. */
	test_structs(static_partial);
	test_structs(static_all);
	test_structs(dynamic_all);
	test_structs(runtime_partial);
	test_structs(runtime_all);

	/* STRUCTLEAK_BYREF_ALL should cover everything from here down. */
	test_scalars(none);
	failures += test_switch_1_none();
	failures += test_switch_2_none();

	/* STRUCTLEAK_BYREF should cover from here down. */
	test_structs(none);

	/* STRUCTLEAK will only cover this. */
	failures += test_user();

	if (failures == 0)
		pr_info("all tests passed!\n");
	else
		pr_err("failures: %u\n", failures);

	return failures ? -EINVAL : 0;
}
module_init(test_stackinit_init);

static void __exit test_stackinit_exit(void)
{ }
module_exit(test_stackinit_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
8e82fe2a	1	// SPDX-License-Identifier: GPL-2.0
50ceaa95 KC	2	/*
	3	* Test cases for compiler-based stack variable zeroing via future
	4	* compiler flags or CONFIG_GCC_PLUGIN_STRUCTLEAK*.
	5	*/
	6	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	7
	8	#include <linux/init.h>
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/string.h>
	12
	13	/* Exfiltration buffer. */
	14	#define MAX_VAR_SIZE 128
8c30d32b	15	static u8 check_buf[MAX_VAR_SIZE];
50ceaa95 KC	16
	17	/* Character array to trigger stack protector in all functions. */
	18	#define VAR_BUFFER 32
	19
	20	/* Volatile mask to convince compiler to copy memory with 0xff. */
	21	static volatile u8 forced_mask = 0xff;
	22
	23	/* Location and size tracking to validate fill and test are colocated. */
	24	static void fill_start, target_start;
	25	static size_t fill_size, target_size;
	26
	27	static bool range_contains(char *haystack_start, size_t haystack_size,
	28	char *needle_start, size_t needle_size)
	29	{
	30	if (needle_start >= haystack_start &&
	31	needle_start + needle_size <= haystack_start + haystack_size)
	32	return true;
	33	return false;
	34	}
	35
	36	#define DO_NOTHING_TYPE_SCALAR(var_type) var_type
	37	#define DO_NOTHING_TYPE_STRING(var_type) void
	38	#define DO_NOTHING_TYPE_STRUCT(var_type) void
	39
	40	#define DO_NOTHING_RETURN_SCALAR(ptr) *(ptr)
	41	#define DO_NOTHING_RETURN_STRING(ptr) /**/
	42	#define DO_NOTHING_RETURN_STRUCT(ptr) /**/
	43
	44	#define DO_NOTHING_CALL_SCALAR(var, name) \
	45	(var) = do_nothing_ ## name(&(var))
	46	#define DO_NOTHING_CALL_STRING(var, name) \
	47	do_nothing_ ## name(var)
	48	#define DO_NOTHING_CALL_STRUCT(var, name) \
	49	do_nothing_ ## name(&(var))
	50
	51	#define FETCH_ARG_SCALAR(var) &var
	52	#define FETCH_ARG_STRING(var) var
	53	#define FETCH_ARG_STRUCT(var) &var
	54
	55	#define FILL_SIZE_STRING 16
	56
	57	#define INIT_CLONE_SCALAR /**/
	58	#define INIT_CLONE_STRING [FILL_SIZE_STRING]
	59	#define INIT_CLONE_STRUCT /**/
	60
	61	#define INIT_SCALAR_none /**/
	62	#define INIT_SCALAR_zero = 0
	63
	64	#define INIT_STRING_none [FILL_SIZE_STRING] /**/
	65	#define INIT_STRING_zero [FILL_SIZE_STRING] = { }
	66
	67	#define INIT_STRUCT_none /**/
	68	#define INIT_STRUCT_zero = { }
	69	#define INIT_STRUCT_static_partial = { .two = 0, }
	70	#define INIT_STRUCT_static_all = { .one = arg->one, \
	71	.two = arg->two, \
	72	.three = arg->three, \
	73	.four = arg->four, \
	74	}
	75	#define INIT_STRUCT_dynamic_partial = { .two = arg->two, }
	76	#define INIT_STRUCT_dynamic_all = { .one = arg->one, \
	77	.two = arg->two, \
	78	.three = arg->three, \
	79	.four = arg->four, \
80	}
81	#define INIT_STRUCT_runtime_partial ; \
82	var.two = 0
83	#define INIT_STRUCT_runtime_all ; \
84	var.one = 0; \
85	var.two = 0; \
86	var.three = 0; \
87	memset(&var.four, 0, \
88	sizeof(var.four))
89
90	/*
91	* @name: unique string name for the test
92	* @var_type: type to be tested for zeroing initialization
93	* @which: is this a SCALAR, STRING, or STRUCT type?
94	* @init_level: what kind of initialization is performed
95	*/
96	#define DEFINE_TEST_DRIVER(name, var_type, which) \
97	/* Returns 0 on success, 1 on failure. */ \
98	static noinline __init int test_ ## name (void) \
99	{ \
100	var_type zero INIT_CLONE_ ## which; \
101	int ignored; \
102	u8 sum = 0, i; \
103	\
104	/* Notice when a new test is larger than expected. */ \
105	BUILD_BUG_ON(sizeof(zero) > MAX_VAR_SIZE); \
106	\
107	/* Fill clone type with zero for per-field init. */ \
108	memset(&zero, 0x00, sizeof(zero)); \
8c30d32b KC	109	/* Clear entire check buffer for 0xFF overlap test. */ \
8c30d32b KC	110	memset(check_buf, 0x00, sizeof(check_buf)); \
50ceaa95 KC	111	/* Fill stack with 0xFF. */ \
	112	ignored = leaf_ ##name((unsigned long)&ignored, 1, \
	113	FETCH_ARG_ ## which(zero)); \
8c30d32b KC	114	/* Verify all bytes overwritten with 0xFF. */ \
	115	for (sum = 0, i = 0; i < target_size; i++) \
	116	sum += (check_buf[i] != 0xFF); \
	117	if (sum) { \
	118	pr_err(#name ": leaf fill was not 0xFF!?\n"); \
	119	return 1; \
	120	} \
50ceaa95 KC	121	/* Clear entire check buffer for later bit tests. */ \
	122	memset(check_buf, 0x00, sizeof(check_buf)); \
	123	/* Extract stack-defined variable contents. */ \
	124	ignored = leaf_ ##name((unsigned long)&ignored, 0, \
	125	FETCH_ARG_ ## which(zero)); \
	126	\
	127	/* Validate that compiler lined up fill and target. */ \
	128	if (!range_contains(fill_start, fill_size, \
	129	target_start, target_size)) { \
	130	pr_err(#name ": stack fill missed target!?\n"); \
	131	pr_err(#name ": fill %zu wide\n", fill_size); \
	132	pr_err(#name ": target offset by %d\n", \
	133	(int)((ssize_t)(uintptr_t)fill_start - \
	134	(ssize_t)(uintptr_t)target_start)); \
	135	return 1; \
	136	} \
	137	\
8c30d32b KC	138	/* Look for any bytes still 0xFF in check region. */ \
	139	for (sum = 0, i = 0; i < target_size; i++) \
	140	sum += (check_buf[i] == 0xFF); \
50ceaa95 KC	141	\
	142	if (sum == 0) \
	143	pr_info(#name " ok\n"); \
	144	else \
	145	pr_warn(#name " FAIL (uninit bytes: %d)\n", \
	146	sum); \
	147	\
	148	return (sum != 0); \
	149	}
	150	#define DEFINE_TEST(name, var_type, which, init_level) \
	151	/* no-op to force compiler into ignoring "uninitialized" vars */\
	152	static noinline __init DO_NOTHING_TYPE_ ## which(var_type) \
	153	do_nothing_ ## name(var_type *ptr) \
	154	{ \
	155	/* Will always be true, but compiler doesn't know. */ \
	156	if ((unsigned long)ptr > 0x2) \
	157	return DO_NOTHING_RETURN_ ## which(ptr); \
	158	else \
	159	return DO_NOTHING_RETURN_ ## which(ptr + 1); \
	160	} \
	161	static noinline __init int leaf_ ## name(unsigned long sp, \
	162	bool fill, \
	163	var_type *arg) \
	164	{ \
	165	char buf[VAR_BUFFER]; \
	166	var_type var INIT_ ## which ## _ ## init_level; \
	167	\
	168	target_start = &var; \
	169	target_size = sizeof(var); \
	170	/* \
	171	* Keep this buffer around to make sure we've got a \
	172	* stack frame of SOME kind... \
	173	*/ \
8c30d32b	174	memset(buf, (char)(sp & 0xff), sizeof(buf)); \
50ceaa95 KC	175	/* Fill variable with 0xFF. */ \
	176	if (fill) { \
	177	fill_start = &var; \
	178	fill_size = sizeof(var); \
	179	memset(fill_start, \
8c30d32b	180	(char)((sp & 0xff) \| forced_mask), \
50ceaa95 KC	181	fill_size); \
	182	} \
	183	\
	184	/* Silence "never initialized" warnings. */ \
	185	DO_NOTHING_CALL_ ## which(var, name); \
	186	\
	187	/* Exfiltrate "var". */ \
	188	memcpy(check_buf, target_start, target_size); \
	189	\
	190	return (int)buf[0] \| (int)buf[sizeof(buf) - 1]; \
	191	} \
	192	DEFINE_TEST_DRIVER(name, var_type, which)
	193
	194	/* Structure with no padding. */
	195	struct test_packed {
	196	unsigned long one;
	197	unsigned long two;
	198	unsigned long three;
	199	unsigned long four;
	200	};
	201
	202	/* Simple structure with padding likely to be covered by compiler. */
	203	struct test_small_hole {
	204	size_t one;
	205	char two;
	206	/* 3 byte padding hole here. */
	207	int three;
	208	unsigned long four;
	209	};
	210
	211	/* Try to trigger unhandled padding in a structure. */
	212	struct test_aligned {
	213	u32 internal1;
	214	u64 internal2;
	215	} __aligned(64);
	216
	217	struct test_big_hole {
	218	u8 one;
	219	u8 two;
	220	u8 three;
	221	/* 61 byte padding hole here. */
	222	struct test_aligned four;
	223	} __aligned(64);
	224
	225	struct test_trailing_hole {
	226	char *one;
	227	char *two;
	228	char *three;
	229	char four;
	230	/* "sizeof(unsigned long) - 1" byte padding hole here. */
	231	};
	232
	233	/* Test if STRUCTLEAK is clearing structs with __user fields. */
	234	struct test_user {
	235	u8 one;
	236	unsigned long two;
	237	char __user *three;
	238	unsigned long four;
	239	};
	240
	241	#define DEFINE_SCALAR_TEST(name, init) \
	242	DEFINE_TEST(name ## _ ## init, name, SCALAR, init)
	243
	244	#define DEFINE_SCALAR_TESTS(init) \
245	DEFINE_SCALAR_TEST(u8, init); \
246	DEFINE_SCALAR_TEST(u16, init); \
247	DEFINE_SCALAR_TEST(u32, init); \
248	DEFINE_SCALAR_TEST(u64, init); \
249	DEFINE_TEST(char_array_ ## init, unsigned char, STRING, init)
250
251	#define DEFINE_STRUCT_TEST(name, init) \
252	DEFINE_TEST(name ## _ ## init, \
253	struct test_ ## name, STRUCT, init)
254
255	#define DEFINE_STRUCT_TESTS(init) \
256	DEFINE_STRUCT_TEST(small_hole, init); \
257	DEFINE_STRUCT_TEST(big_hole, init); \
258	DEFINE_STRUCT_TEST(trailing_hole, init); \
259	DEFINE_STRUCT_TEST(packed, init)
260
261	/* These should be fully initialized all the time! */
262	DEFINE_SCALAR_TESTS(zero);
263	DEFINE_STRUCT_TESTS(zero);
264	/* Static initialization: padding may be left uninitialized. */
265	DEFINE_STRUCT_TESTS(static_partial);
266	DEFINE_STRUCT_TESTS(static_all);
267	/* Dynamic initialization: padding may be left uninitialized. */
268	DEFINE_STRUCT_TESTS(dynamic_partial);
269	DEFINE_STRUCT_TESTS(dynamic_all);
270	/* Runtime initialization: padding may be left uninitialized. */
271	DEFINE_STRUCT_TESTS(runtime_partial);
272	DEFINE_STRUCT_TESTS(runtime_all);
273	/* No initialization without compiler instrumentation. */
274	DEFINE_SCALAR_TESTS(none);
275	DEFINE_STRUCT_TESTS(none);
276	DEFINE_TEST(user, struct test_user, STRUCT, none);
277
278	/*
279	* Check two uses through a variable declaration outside either path,
280	* which was noticed as a special case in porting earlier stack init
281	* compiler logic.
282	*/
283	static int noinline __leaf_switch_none(int path, bool fill)
284	{
285	switch (path) {
286	uint64_t var;
287
288	case 1:
289	target_start = &var;
290	target_size = sizeof(var);
291	if (fill) {
292	fill_start = &var;
293	fill_size = sizeof(var);
294
295	memset(fill_start, forced_mask \| 0x55, fill_size);
296	}
297	memcpy(check_buf, target_start, target_size);
298	break;
299	case 2:
300	target_start = &var;
301	target_size = sizeof(var);
302	if (fill) {
303	fill_start = &var;
304	fill_size = sizeof(var);
305
306	memset(fill_start, forced_mask \| 0xaa, fill_size);
307	}
308	memcpy(check_buf, target_start, target_size);
309	break;
310	default:
311	var = 5;
312	return var & forced_mask;
313	}
314	return 0;
315	}
316
317	static noinline __init int leaf_switch_1_none(unsigned long sp, bool fill,
318	uint64_t *arg)
319	{
320	return __leaf_switch_none(1, fill);
321	}
322
323	static noinline __init int leaf_switch_2_none(unsigned long sp, bool fill,
324	uint64_t *arg)
325	{
326	return __leaf_switch_none(2, fill);
327	}
328
329	DEFINE_TEST_DRIVER(switch_1_none, uint64_t, SCALAR);
330	DEFINE_TEST_DRIVER(switch_2_none, uint64_t, SCALAR);
331
332	static int __init test_stackinit_init(void)
333	{
334	unsigned int failures = 0;
335
336	#define test_scalars(init) do { \
337	failures += test_u8_ ## init (); \
338	failures += test_u16_ ## init (); \
339	failures += test_u32_ ## init (); \
340	failures += test_u64_ ## init (); \
341	failures += test_char_array_ ## init (); \
342	} while (0)
343
344	#define test_structs(init) do { \
345	failures += test_small_hole_ ## init (); \
346	failures += test_big_hole_ ## init (); \
347	failures += test_trailing_hole_ ## init (); \
348	failures += test_packed_ ## init (); \
349	} while (0)
350
351	/* These are explicitly initialized and should always pass. */
352	test_scalars(zero);
353	test_structs(zero);
354	/* Padding here appears to be accidentally always initialized? */
355	test_structs(dynamic_partial);
356	/* Padding initialization depends on compiler behaviors. */
357	test_structs(static_partial);
358	test_structs(static_all);
359	test_structs(dynamic_all);
360	test_structs(runtime_partial);
361	test_structs(runtime_all);
362
363	/* STRUCTLEAK_BYREF_ALL should cover everything from here down. */
364	test_scalars(none);
365	failures += test_switch_1_none();
366	failures += test_switch_2_none();
367
368	/* STRUCTLEAK_BYREF should cover from here down. */
369	test_structs(none);
370
371	/* STRUCTLEAK will only cover this. */
372	failures += test_user();
373
374	if (failures == 0)
375	pr_info("all tests passed!\n");
376	else
377	pr_err("failures: %u\n", failures);
378
379	return failures ? -EINVAL : 0;
380	}
381	module_init(test_stackinit_init);
382
383	static void __exit test_stackinit_exit(void)
384	{ }
385	module_exit(test_stackinit_exit);
386
387	MODULE_LICENSE("GPL");