|  | // 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 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); | 
|  | 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 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_DESCRIPTION("Test cases for SL[AOU]B/page initialization at alloc/free time"); | 
|  | MODULE_LICENSE("GPL"); |