[mirror_ubuntu-jammy-kernel.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, size_t size, size_t skip)
{
	unsigned int *p = (unsigned int *)ptr;
	int i = 0;

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