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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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");