diff options
Diffstat (limited to 'lib/slub_kunit.c')
| -rw-r--r-- | lib/slub_kunit.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c new file mode 100644 index 000000000000..d4a3730b08fa --- /dev/null +++ b/lib/slub_kunit.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <kunit/test.h> +#include <kunit/test-bug.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include "../mm/slab.h" + +static struct kunit_resource resource; +static int slab_errors; + +/* + * Wrapper function for kmem_cache_create(), which reduces 2 parameters: + * 'align' and 'ctor', and sets SLAB_SKIP_KFENCE flag to avoid getting an + * object from kfence pool, where the operation could be caught by both + * our test and kfence sanity check. + */ +static struct kmem_cache *test_kmem_cache_create(const char *name, + unsigned int size, slab_flags_t flags) +{ + struct kmem_cache *s = kmem_cache_create(name, size, 0, + (flags | SLAB_NO_USER_FLAGS), NULL); + s->flags |= SLAB_SKIP_KFENCE; + return s; +} + +static void test_clobber_zone(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_alloc", 64, + SLAB_RED_ZONE); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kasan_disable_current(); + p[64] = 0x12; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + kasan_enable_current(); + kmem_cache_free(s, p); + kmem_cache_destroy(s); +} + +#ifndef CONFIG_KASAN +static void test_next_pointer(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_next_ptr_free", + 64, SLAB_POISON); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + unsigned long tmp; + unsigned long *ptr_addr; + + kmem_cache_free(s, p); + + ptr_addr = (unsigned long *)(p + s->offset); + tmp = *ptr_addr; + p[s->offset] = 0x12; + + /* + * Expecting three errors. + * One for the corrupted freechain and the other one for the wrong + * count of objects in use. The third error is fixing broken cache. + */ + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 3, slab_errors); + + /* + * Try to repair corrupted freepointer. + * Still expecting two errors. The first for the wrong count + * of objects in use. + * The second error is for fixing broken cache. + */ + *ptr_addr = tmp; + slab_errors = 0; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + /* + * Previous validation repaired the count of objects in use. + * Now expecting no error. + */ + slab_errors = 0; + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 0, slab_errors); + + kmem_cache_destroy(s); +} + +static void test_first_word(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_1th_word_free", + 64, SLAB_POISON); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + *p = 0x78; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + kmem_cache_destroy(s); +} + +static void test_clobber_50th_byte(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_50th_word_free", + 64, SLAB_POISON); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + p[50] = 0x9a; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + kmem_cache_destroy(s); +} +#endif + +static void test_clobber_redzone_free(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_free", 64, + SLAB_RED_ZONE); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kasan_disable_current(); + kmem_cache_free(s, p); + p[64] = 0xab; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + kasan_enable_current(); + kmem_cache_destroy(s); +} + +static void test_kmalloc_redzone_access(struct kunit *test) +{ + struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32, + SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE); + u8 *p = kmalloc_trace(s, GFP_KERNEL, 18); + + kasan_disable_current(); + + /* Suppress the -Warray-bounds warning */ + OPTIMIZER_HIDE_VAR(p); + p[18] = 0xab; + p[19] = 0xab; + + validate_slab_cache(s); + KUNIT_EXPECT_EQ(test, 2, slab_errors); + + kasan_enable_current(); + kmem_cache_free(s, p); + kmem_cache_destroy(s); +} + +static int test_init(struct kunit *test) +{ + slab_errors = 0; + + kunit_add_named_resource(test, NULL, NULL, &resource, + "slab_errors", &slab_errors); + return 0; +} + +static struct kunit_case test_cases[] = { + KUNIT_CASE(test_clobber_zone), + +#ifndef CONFIG_KASAN + KUNIT_CASE(test_next_pointer), + KUNIT_CASE(test_first_word), + KUNIT_CASE(test_clobber_50th_byte), +#endif + + KUNIT_CASE(test_clobber_redzone_free), + KUNIT_CASE(test_kmalloc_redzone_access), + {} +}; + +static struct kunit_suite test_suite = { + .name = "slub_test", + .init = test_init, + .test_cases = test_cases, +}; +kunit_test_suite(test_suite); + +MODULE_LICENSE("GPL"); |