lib/test_meminit.c - third_party/linux - Git at Google

 // 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 < MAX_ORDER; 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;
 }

 #define BULK_SIZE 100
 static void *bulk_array[BULK_SIZE];

 /*
  * 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++) {
 		/* Do a test of bulk allocations */
 		if (!want_rcu && !want_ctor) {
 			int ret;

 			ret = kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE, bulk_array);
 			if (!ret) {
 				fail = true;
 			} else {
 				int i;
 				for (i = 0; i < ret; i++)
 					fail |= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);
 				kmem_cache_free_bulk(c, ret, bulk_array);
 			}
 		}

 		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;
 }

 static int __init do_kmem_cache_size_bulk(int size, int *total_failures)
 {
 	struct kmem_cache *c;
 	int i, iter, maxiter = 1024;
 	int num, bytes;
 	bool fail = false;
 	void *objects[10];

 	c = kmem_cache_create("test_cache", size, size, 0, NULL);
 	for (iter = 0; (iter < maxiter) && !fail; iter++) {
 		num = kmem_cache_alloc_bulk(c, GFP_KERNEL, ARRAY_SIZE(objects),
 					    objects);
 		for (i = 0; i < num; i++) {
 			bytes = count_nonzero_bytes(objects[i], size);
 			if (bytes)
 				fail = true;
 			fill_with_garbage(objects[i], size);
 		}

 		if (num)
 			kmem_cache_free_bulk(c, num, objects);
 	}
 	kmem_cache_destroy(c);
 	*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);
 		}
 		num_tests += do_kmem_cache_size_bulk(size, &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");
	// 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 < MAX_ORDER; 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;
	}

	#define BULK_SIZE 100
	static void *bulk_array[BULK_SIZE];

	/*
	* 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++) {
	/* Do a test of bulk allocations */
	if (!want_rcu && !want_ctor) {
	int ret;

	ret = kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE, bulk_array);
	if (!ret) {
	fail = true;
	} else {
	int i;
	for (i = 0; i < ret; i++)
	fail \|= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);
	kmem_cache_free_bulk(c, ret, bulk_array);
	}
	}

	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;
	}

	static int __init do_kmem_cache_size_bulk(int size, int *total_failures)
	{
	struct kmem_cache *c;
	int i, iter, maxiter = 1024;
	int num, bytes;
	bool fail = false;
	void *objects[10];

	c = kmem_cache_create("test_cache", size, size, 0, NULL);
	for (iter = 0; (iter < maxiter) && !fail; iter++) {
	num = kmem_cache_alloc_bulk(c, GFP_KERNEL, ARRAY_SIZE(objects),
	objects);
	for (i = 0; i < num; i++) {
	bytes = count_nonzero_bytes(objects[i], size);
	if (bytes)
	fail = true;
	fill_with_garbage(objects[i], size);
	}

	if (num)
	kmem_cache_free_bulk(c, num, objects);
	}
	kmem_cache_destroy(c);
	*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);
	}
	num_tests += do_kmem_cache_size_bulk(size, &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");