[linux-2.6-block.git] / lib / test_meminit.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Test cases for SL[AOU]B/page initialization at alloc/free time.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

#define GARBAGE_INT (0x09A7BA9E)
#define GARBAGE_BYTE (0x9E)

#define REPORT_FAILURES_IN_FN() \
	do {	\
		if (failures)	\
			pr_info("%s failed %d out of %d times\n",	\
				__func__, failures, num_tests);		\
		else		\
			pr_info("all %d tests in %s passed\n",		\
				num_tests, __func__);			\
	} while (0)

/* Calculate the number of uninitialized bytes in the buffer. */
static int __init count_nonzero_bytes(void *ptr, size_t size)
{
	int i, ret = 0;
	unsigned char *p = (unsigned char *)ptr;

	for (i = 0; i < size; i++)
		if (p[i])
			ret++;
	return ret;
}

/* Fill a buffer with garbage, skipping |skip| first bytes. */
static void __init fill_with_garbage_skip(void *ptr, int size, size_t skip)
{
	unsigned int *p = (unsigned int *)((char *)ptr + skip);
	int i = 0;

	WARN_ON(skip > size);
	size -= skip;

	while (size >= sizeof(*p)) {
		p[i] = GARBAGE_INT;
		i++;
		size -= sizeof(*p);
	}
	if (size)
		memset(&p[i], GARBAGE_BYTE, size);
}

static void __init fill_with_garbage(void *ptr, size_t size)
{
	fill_with_garbage_skip(ptr, size, 0);
}

static int __init do_alloc_pages_order(int order, int *total_failures)
{
	struct page *page;
	void *buf;
	size_t size = PAGE_SIZE << order;

	page = alloc_pages(GFP_KERNEL, order);
	buf = page_address(page);
	fill_with_garbage(buf, size);
	__free_pages(page, order);

	page = alloc_pages(GFP_KERNEL, order);
	buf = page_address(page);
	if (count_nonzero_bytes(buf, size))
		(*total_failures)++;
	fill_with_garbage(buf, size);
	__free_pages(page, order);
	return 1;
}

/* Test the page allocator by calling alloc_pages with different orders. */
static int __init test_pages(int *total_failures)
{
	int failures = 0, num_tests = 0;
	int i;

	for (i = 0; i < 10; i++)
		num_tests += do_alloc_pages_order(i, &failures);

	REPORT_FAILURES_IN_FN();
	*total_failures += failures;
	return num_tests;
}

/* Test kmalloc() with given parameters. */
static int __init do_kmalloc_size(size_t size, int *total_failures)
{
	void *buf;

	buf = kmalloc(size, GFP_KERNEL);
	fill_with_garbage(buf, size);
	kfree(buf);

	buf = kmalloc(size, GFP_KERNEL);
	if (count_nonzero_bytes(buf, size))
		(*total_failures)++;
	fill_with_garbage(buf, size);
	kfree(buf);
	return 1;
}

/* Test vmalloc() with given parameters. */
static int __init do_vmalloc_size(size_t size, int *total_failures)
{
	void *buf;

	buf = vmalloc(size);
	fill_with_garbage(buf, size);
	vfree(buf);

	buf = vmalloc(size);
	if (count_nonzero_bytes(buf, size))
		(*total_failures)++;
	fill_with_garbage(buf, size);
	vfree(buf);
	return 1;
}

/* Test kmalloc()/vmalloc() by allocating objects of different sizes. */
static int __init test_kvmalloc(int *total_failures)
{
	int failures = 0, num_tests = 0;
	int i, size;

	for (i = 0; i < 20; i++) {
		size = 1 << i;
		num_tests += do_kmalloc_size(size, &failures);
		num_tests += do_vmalloc_size(size, &failures);
	}

	REPORT_FAILURES_IN_FN();
	*total_failures += failures;
	return num_tests;
}

#define CTOR_BYTES (sizeof(unsigned int))
#define CTOR_PATTERN (0x41414141)
/* Initialize the first 4 bytes of the object. */
static void test_ctor(void *obj)
{
	*(unsigned int *)obj = CTOR_PATTERN;
}

/*
 * Check the invariants for the buffer allocated from a slab cache.
 * If the cache has a test constructor, the first 4 bytes of the object must
 * always remain equal to CTOR_PATTERN.
 * If the cache isn't an RCU-typesafe one, or if the allocation is done with
 * __GFP_ZERO, then the object contents must be zeroed after allocation.
 * If the cache is an RCU-typesafe one, the object contents must never be
 * zeroed after the first use. This is checked by memcmp() in
 * do_kmem_cache_size().
 */
static bool __init check_buf(void *buf, int size, bool want_ctor,
			     bool want_rcu, bool want_zero)
{
	int bytes;
	bool fail = false;

	bytes = count_nonzero_bytes(buf, size);
	WARN_ON(want_ctor && want_zero);
	if (want_zero)
		return bytes;
	if (want_ctor) {
		if (*(unsigned int *)buf != CTOR_PATTERN)
			fail = 1;
	} else {
		if (bytes)
			fail = !want_rcu;
	}
	return fail;
}

/*
 * Test kmem_cache with given parameters:
 *  want_ctor - use a constructor;
 *  want_rcu - use SLAB_TYPESAFE_BY_RCU;
 *  want_zero - use __GFP_ZERO.
 */
static int __init do_kmem_cache_size(size_t size, bool want_ctor,
				     bool want_rcu, bool want_zero,
				     int *total_failures)
{
	struct kmem_cache *c;
	int iter;
	bool fail = false;
	gfp_t alloc_mask = GFP_KERNEL | (want_zero ? __GFP_ZERO : 0);
	void *buf, *buf_copy;

	c = kmem_cache_create("test_cache", size, 1,
			      want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
			      want_ctor ? test_ctor : NULL);
	for (iter = 0; iter < 10; iter++) {
		buf = kmem_cache_alloc(c, alloc_mask);
		/* Check that buf is zeroed, if it must be. */
		fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
		fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);

		if (!want_rcu) {
			kmem_cache_free(c, buf);
			continue;
		}

		/*
		 * If this is an RCU cache, use a critical section to ensure we
		 * can touch objects after they're freed.
		 */
		rcu_read_lock();
		/*
		 * Copy the buffer to check that it's not wiped on
		 * free().
		 */
		buf_copy = kmalloc(size, GFP_ATOMIC);
		if (buf_copy)
			memcpy(buf_copy, buf, size);

		kmem_cache_free(c, buf);
		/*
		 * Check that |buf| is intact after kmem_cache_free().
		 * |want_zero| is false, because we wrote garbage to
		 * the buffer already.
		 */
		fail |= check_buf(buf, size, want_ctor, want_rcu,
				  false);
		if (buf_copy) {
			fail |= (bool)memcmp(buf, buf_copy, size);
			kfree(buf_copy);
		}
		rcu_read_unlock();
	}
	kmem_cache_destroy(c);

	*total_failures += fail;
	return 1;
}

/*
 * Check that the data written to an RCU-allocated object survives
 * reallocation.
 */
static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
{
	struct kmem_cache *c;
	void *buf, *buf_contents, *saved_ptr;
	void **used_objects;
	int i, iter, maxiter = 1024;
	bool fail = false;

	c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
			      NULL);
	buf = kmem_cache_alloc(c, GFP_KERNEL);
	saved_ptr = buf;
	fill_with_garbage(buf, size);
	buf_contents = kmalloc(size, GFP_KERNEL);
	if (!buf_contents)
		goto out;
	used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);
	if (!used_objects) {
		kfree(buf_contents);
		goto out;
	}
	memcpy(buf_contents, buf, size);
	kmem_cache_free(c, buf);
	/*
	 * Run for a fixed number of iterations. If we never hit saved_ptr,
	 * assume the test passes.
	 */
	for (iter = 0; iter < maxiter; iter++) {
		buf = kmem_cache_alloc(c, GFP_KERNEL);
		used_objects[iter] = buf;
		if (buf == saved_ptr) {
			fail = memcmp(buf_contents, buf, size);
			for (i = 0; i <= iter; i++)
				kmem_cache_free(c, used_objects[i]);
			goto free_out;
		}
	}

free_out:
	kmem_cache_destroy(c);
	kfree(buf_contents);
	kfree(used_objects);
out:
	*total_failures += fail;
	return 1;
}

/*
 * Test kmem_cache allocation by creating caches of different sizes, with and
 * without constructors, with and without SLAB_TYPESAFE_BY_RCU.
 */
static int __init test_kmemcache(int *total_failures)
{
	int failures = 0, num_tests = 0;
	int i, flags, size;
	bool ctor, rcu, zero;

	for (i = 0; i < 10; i++) {
		size = 8 << i;
		for (flags = 0; flags < 8; flags++) {
			ctor = flags & 1;
			rcu = flags & 2;
			zero = flags & 4;
			if (ctor & zero)
				continue;
			num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
							&failures);
		}
	}
	REPORT_FAILURES_IN_FN();
	*total_failures += failures;
	return num_tests;
}

/* Test the behavior of SLAB_TYPESAFE_BY_RCU caches of different sizes. */
static int __init test_rcu_persistent(int *total_failures)
{
	int failures = 0, num_tests = 0;
	int i, size;

	for (i = 0; i < 10; i++) {
		size = 8 << i;
		num_tests += do_kmem_cache_rcu_persistent(size, &failures);
	}
	REPORT_FAILURES_IN_FN();
	*total_failures += failures;
	return num_tests;
}

/*
 * Run the tests. Each test function returns the number of executed tests and
 * updates |failures| with the number of failed tests.
 */
static int __init test_meminit_init(void)
{
	int failures = 0, num_tests = 0;

	num_tests += test_pages(&failures);
	num_tests += test_kvmalloc(&failures);
	num_tests += test_kmemcache(&failures);
	num_tests += test_rcu_persistent(&failures);

	if (failures == 0)
		pr_info("all %d tests passed!\n", num_tests);
	else
		pr_info("failures: %d out of %d\n", failures, num_tests);

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

MODULE_LICENSE("GPL");
Commit	Line	Data
5015a300 AP	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Test cases for SL[AOU]B/page initialization at alloc/free time.
	4	*/
	5	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	6
	7	#include <linux/init.h>
	8	#include <linux/kernel.h>
	9	#include <linux/mm.h>
	10	#include <linux/module.h>
	11	#include <linux/slab.h>
	12	#include <linux/string.h>
	13	#include <linux/vmalloc.h>
	14
	15	#define GARBAGE_INT (0x09A7BA9E)
	16	#define GARBAGE_BYTE (0x9E)
	17
	18	#define REPORT_FAILURES_IN_FN() \
	19	do { \
	20	if (failures) \
	21	pr_info("%s failed %d out of %d times\n", \
	22	__func__, failures, num_tests); \
	23	else \
	24	pr_info("all %d tests in %s passed\n", \
	25	num_tests, __func__); \
	26	} while (0)
	27
	28	/* Calculate the number of uninitialized bytes in the buffer. */
	29	static int __init count_nonzero_bytes(void *ptr, size_t size)
	30	{
	31	int i, ret = 0;
	32	unsigned char p = (unsigned char )ptr;
	33
	34	for (i = 0; i < size; i++)
	35	if (p[i])
	36	ret++;
	37	return ret;
	38	}
	39
	40	/* Fill a buffer with garbage, skipping \|skip\| first bytes. */
4ab7ace4	41	static void __init fill_with_garbage_skip(void *ptr, int size, size_t skip)
5015a300	42	{
4ab7ace4	43	unsigned int p = (unsigned int )((char *)ptr + skip);
5015a300 AP	44	int i = 0;
5015a300 AP	45
4ab7ace4 AP	46	WARN_ON(skip > size);
	47	size -= skip;
	48
5015a300 AP	49	while (size >= sizeof(*p)) {
	50	p[i] = GARBAGE_INT;
	51	i++;
	52	size -= sizeof(*p);
	53	}
	54	if (size)
	55	memset(&p[i], GARBAGE_BYTE, size);
	56	}
	57
	58	static void __init fill_with_garbage(void *ptr, size_t size)
	59	{
	60	fill_with_garbage_skip(ptr, size, 0);
	61	}
	62
	63	static int __init do_alloc_pages_order(int order, int *total_failures)
	64	{
	65	struct page *page;
	66	void *buf;
	67	size_t size = PAGE_SIZE << order;
	68
	69	page = alloc_pages(GFP_KERNEL, order);
	70	buf = page_address(page);
	71	fill_with_garbage(buf, size);
	72	__free_pages(page, order);
	73
	74	page = alloc_pages(GFP_KERNEL, order);
	75	buf = page_address(page);
	76	if (count_nonzero_bytes(buf, size))
	77	(*total_failures)++;
	78	fill_with_garbage(buf, size);
	79	__free_pages(page, order);
	80	return 1;
	81	}
	82
	83	/* Test the page allocator by calling alloc_pages with different orders. */
	84	static int __init test_pages(int *total_failures)
	85	{
	86	int failures = 0, num_tests = 0;
	87	int i;
	88
	89	for (i = 0; i < 10; i++)
	90	num_tests += do_alloc_pages_order(i, &failures);
	91
	92	REPORT_FAILURES_IN_FN();
	93	*total_failures += failures;
	94	return num_tests;
	95	}
	96
	97	/* Test kmalloc() with given parameters. */
	98	static int __init do_kmalloc_size(size_t size, int *total_failures)
	99	{
	100	void *buf;
	101
	102	buf = kmalloc(size, GFP_KERNEL);
	103	fill_with_garbage(buf, size);
	104	kfree(buf);
	105
	106	buf = kmalloc(size, GFP_KERNEL);
	107	if (count_nonzero_bytes(buf, size))
	108	(*total_failures)++;
	109	fill_with_garbage(buf, size);
	110	kfree(buf);
	111	return 1;
	112	}
113
114	/* Test vmalloc() with given parameters. */
115	static int __init do_vmalloc_size(size_t size, int *total_failures)
116	{
117	void *buf;
118
119	buf = vmalloc(size);
120	fill_with_garbage(buf, size);
121	vfree(buf);
122
123	buf = vmalloc(size);
124	if (count_nonzero_bytes(buf, size))
125	(*total_failures)++;
126	fill_with_garbage(buf, size);
127	vfree(buf);
128	return 1;
129	}
130
131	/* Test kmalloc()/vmalloc() by allocating objects of different sizes. */
132	static int __init test_kvmalloc(int *total_failures)
133	{
134	int failures = 0, num_tests = 0;
135	int i, size;
136
137	for (i = 0; i < 20; i++) {
138	size = 1 << i;
139	num_tests += do_kmalloc_size(size, &failures);
140	num_tests += do_vmalloc_size(size, &failures);
141	}
142
143	REPORT_FAILURES_IN_FN();
144	*total_failures += failures;
145	return num_tests;
146	}
147
148	#define CTOR_BYTES (sizeof(unsigned int))
149	#define CTOR_PATTERN (0x41414141)
150	/* Initialize the first 4 bytes of the object. */
151	static void test_ctor(void *obj)
152	{
153	(unsigned int )obj = CTOR_PATTERN;
154	}
155
156	/*
157	* Check the invariants for the buffer allocated from a slab cache.
158	* If the cache has a test constructor, the first 4 bytes of the object must
159	* always remain equal to CTOR_PATTERN.
160	* If the cache isn't an RCU-typesafe one, or if the allocation is done with
161	* __GFP_ZERO, then the object contents must be zeroed after allocation.
162	* If the cache is an RCU-typesafe one, the object contents must never be
163	* zeroed after the first use. This is checked by memcmp() in
164	* do_kmem_cache_size().
165	*/
166	static bool __init check_buf(void *buf, int size, bool want_ctor,
167	bool want_rcu, bool want_zero)
168	{
169	int bytes;
170	bool fail = false;
171
172	bytes = count_nonzero_bytes(buf, size);
173	WARN_ON(want_ctor && want_zero);
174	if (want_zero)
175	return bytes;
176	if (want_ctor) {
177	if ((unsigned int )buf != CTOR_PATTERN)
178	fail = 1;
179	} else {
180	if (bytes)
181	fail = !want_rcu;
182	}
183	return fail;
184	}
185
186	/*
187	* Test kmem_cache with given parameters:
188	* want_ctor - use a constructor;
189	* want_rcu - use SLAB_TYPESAFE_BY_RCU;
190	* want_zero - use __GFP_ZERO.
191	*/
192	static int __init do_kmem_cache_size(size_t size, bool want_ctor,
193	bool want_rcu, bool want_zero,
194	int *total_failures)
195	{
196	struct kmem_cache *c;
197	int iter;
198	bool fail = false;
199	gfp_t alloc_mask = GFP_KERNEL \| (want_zero ? __GFP_ZERO : 0);
200	void buf, buf_copy;
201
202	c = kmem_cache_create("test_cache", size, 1,
203	want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
204	want_ctor ? test_ctor : NULL);
205	for (iter = 0; iter < 10; iter++) {
206	buf = kmem_cache_alloc(c, alloc_mask);
207	/* Check that buf is zeroed, if it must be. */
208	fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
209	fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);
d3a81161 AB	210
	211	if (!want_rcu) {
	212	kmem_cache_free(c, buf);
	213	continue;
	214	}
	215
5015a300 AP	216	/*
	217	* If this is an RCU cache, use a critical section to ensure we
	218	* can touch objects after they're freed.
	219	*/
d3a81161 AB	220	rcu_read_lock();
	221	/*
	222	* Copy the buffer to check that it's not wiped on
	223	* free().
	224	*/
733d1d1a	225	buf_copy = kmalloc(size, GFP_ATOMIC);
d3a81161 AB	226	if (buf_copy)
	227	memcpy(buf_copy, buf, size);
	228
4ab7ace4	229	kmem_cache_free(c, buf);
d3a81161 AB	230	/*
	231	* Check that \|buf\| is intact after kmem_cache_free().
	232	* \|want_zero\| is false, because we wrote garbage to
	233	* the buffer already.
	234	*/
	235	fail \|= check_buf(buf, size, want_ctor, want_rcu,
	236	false);
	237	if (buf_copy) {
	238	fail \|= (bool)memcmp(buf, buf_copy, size);
	239	kfree(buf_copy);
5015a300	240	}
d3a81161	241	rcu_read_unlock();
5015a300 AP	242	}
	243	kmem_cache_destroy(c);
	244
	245	*total_failures += fail;
	246	return 1;
	247	}
	248
	249	/*
	250	* Check that the data written to an RCU-allocated object survives
	251	* reallocation.
	252	*/
	253	static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
	254	{
	255	struct kmem_cache *c;
	256	void buf, buf_contents, *saved_ptr;
	257	void **used_objects;
	258	int i, iter, maxiter = 1024;
	259	bool fail = false;
	260
	261	c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
	262	NULL);
	263	buf = kmem_cache_alloc(c, GFP_KERNEL);
	264	saved_ptr = buf;
	265	fill_with_garbage(buf, size);
	266	buf_contents = kmalloc(size, GFP_KERNEL);
	267	if (!buf_contents)
	268	goto out;
	269	used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);
	270	if (!used_objects) {
	271	kfree(buf_contents);
	272	goto out;
	273	}
	274	memcpy(buf_contents, buf, size);
	275	kmem_cache_free(c, buf);
	276	/*
	277	* Run for a fixed number of iterations. If we never hit saved_ptr,
	278	* assume the test passes.
	279	*/
	280	for (iter = 0; iter < maxiter; iter++) {
	281	buf = kmem_cache_alloc(c, GFP_KERNEL);
	282	used_objects[iter] = buf;
	283	if (buf == saved_ptr) {
	284	fail = memcmp(buf_contents, buf, size);
	285	for (i = 0; i <= iter; i++)
	286	kmem_cache_free(c, used_objects[i]);
	287	goto free_out;
	288	}
	289	}
	290
	291	free_out:
	292	kmem_cache_destroy(c);
	293	kfree(buf_contents);
	294	kfree(used_objects);
	295	out:
	296	*total_failures += fail;
	297	return 1;
	298	}
	299
	300	/*
	301	* Test kmem_cache allocation by creating caches of different sizes, with and
	302	* without constructors, with and without SLAB_TYPESAFE_BY_RCU.
	303	*/
	304	static int __init test_kmemcache(int *total_failures)
	305	{
306	int failures = 0, num_tests = 0;
307	int i, flags, size;
308	bool ctor, rcu, zero;
309
310	for (i = 0; i < 10; i++) {
311	size = 8 << i;
312	for (flags = 0; flags < 8; flags++) {
313	ctor = flags & 1;
314	rcu = flags & 2;
315	zero = flags & 4;
316	if (ctor & zero)
317	continue;
318	num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
319	&failures);
320	}
321	}
322	REPORT_FAILURES_IN_FN();
323	*total_failures += failures;
324	return num_tests;
325	}
326
327	/* Test the behavior of SLAB_TYPESAFE_BY_RCU caches of different sizes. */
328	static int __init test_rcu_persistent(int *total_failures)
329	{
330	int failures = 0, num_tests = 0;
331	int i, size;
332
333	for (i = 0; i < 10; i++) {
334	size = 8 << i;
335	num_tests += do_kmem_cache_rcu_persistent(size, &failures);
336	}
337	REPORT_FAILURES_IN_FN();
338	*total_failures += failures;
339	return num_tests;
340	}
341
342	/*
343	* Run the tests. Each test function returns the number of executed tests and
344	* updates \|failures\| with the number of failed tests.
345	*/
346	static int __init test_meminit_init(void)
347	{
348	int failures = 0, num_tests = 0;
349
350	num_tests += test_pages(&failures);
351	num_tests += test_kvmalloc(&failures);
352	num_tests += test_kmemcache(&failures);
353	num_tests += test_rcu_persistent(&failures);
354
355	if (failures == 0)
356	pr_info("all %d tests passed!\n", num_tests);
357	else
358	pr_info("failures: %d out of %d\n", failures, num_tests);
359
360	return failures ? -EINVAL : 0;
361	}
362	module_init(test_meminit_init);
363
364	MODULE_LICENSE("GPL");