// 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);	if (!page)		goto err;	buf = page_address(page);	fill_with_garbage(buf, size);	__free_pages(page, order); 	page = alloc_pages(GFP_KERNEL, order);	if (!page)		goto err;	buf = page_address(page);	if (count_nonzero_bytes(buf, size))		(*total_failures)++;	fill_with_garbage(buf, size);	__free_pages(page, order);	return 1;err:	(*total_failures)++;	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 < NR_PAGE_ORDERS; 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);	if (!buf)		goto err;	fill_with_garbage(buf, size);	kfree(buf); 	buf = kmalloc(size, GFP_KERNEL);	if (!buf)		goto err;	if (count_nonzero_bytes(buf, size))		(*total_failures)++;	fill_with_garbage(buf, size);	kfree(buf);	return 1;err:	(*total_failures)++;	return 1;} /* Test vmalloc() with given parameters. */static int __init do_vmalloc_size(size_t size, int *total_failures){	void *buf; 	buf = vmalloc(size);	if (!buf)		goto err;	fill_with_garbage(buf, size);	vfree(buf); 	buf = vmalloc(size);	if (!buf)		goto err;	if (count_nonzero_bytes(buf, size))		(*total_failures)++;	fill_with_garbage(buf, size);	vfree(buf);	return 1;err:	(*total_failures)++;	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 100static 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) {			if (!kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE,					bulk_array)) {				fail = true;			} else {				int i;				for (i = 0; i < BULK_SIZE; i++)					fail |= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);				kmem_cache_free_bulk(c, BULK_SIZE, 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);	if (!buf)		goto out;	saved_ptr = buf;	fill_with_garbage(buf, size);	buf_contents = kmalloc(size, GFP_KERNEL);	if (!buf_contents) {		kmem_cache_free(c, buf);		goto out;	}	used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);	if (!used_objects) {		kmem_cache_free(c, buf);		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;		}	} 	for (iter = 0; iter < maxiter; iter++)		kmem_cache_free(c, used_objects[iter]); free_out:	kfree(buf_contents);	kfree(used_objects);out:	kmem_cache_destroy(c);	*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 bytes;	bool fail = false;	void *objects[10]; 	c = kmem_cache_create("test_cache", size, size, 0, NULL);	for (iter = 0; (iter < maxiter) && !fail; iter++) {		if (!kmem_cache_alloc_bulk(c, GFP_KERNEL, ARRAY_SIZE(objects),				objects))			continue; 		for (i = 0; i < ARRAY_SIZE(objects); i++) {			bytes = count_nonzero_bytes(objects[i], size);			if (bytes)				fail = true;			fill_with_garbage(objects[i], size);		} 		kmem_cache_free_bulk(c, ARRAY_SIZE(objects), 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_DESCRIPTION("Test cases for SL[AOU]B/page initialization at alloc/free time");MODULE_LICENSE("GPL");