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Diffstat (limited to 'lib/fortify_kunit.c')
| -rw-r--r-- | lib/fortify_kunit.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c new file mode 100644 index 0000000000..c8c33cbaae --- /dev/null +++ b/lib/fortify_kunit.c @@ -0,0 +1,331 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to + * Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c) + * + * For corner cases with UBSAN, try testing with: + * + * ./tools/testing/kunit/kunit.py run --arch=x86_64 \ + * --kconfig_add CONFIG_FORTIFY_SOURCE=y \ + * --kconfig_add CONFIG_UBSAN=y \ + * --kconfig_add CONFIG_UBSAN_TRAP=y \ + * --kconfig_add CONFIG_UBSAN_BOUNDS=y \ + * --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \ + * --make_options LLVM=1 fortify + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <kunit/test.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/vmalloc.h> + +static const char array_of_10[] = "this is 10"; +static const char *ptr_of_11 = "this is 11!"; +static char array_unknown[] = "compiler thinks I might change"; + +static void known_sizes_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); + KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); + KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); + + KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); + /* Externally defined and dynamically sized string pointer: */ + KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); +} + +/* This is volatile so the optimizer can't perform DCE below. */ +static volatile int pick; + +/* Not inline to keep optimizer from figuring out which string we want. */ +static noinline size_t want_minus_one(int pick) +{ + const char *str; + + switch (pick) { + case 1: + str = "4444"; + break; + case 2: + str = "333"; + break; + default: + str = "1"; + break; + } + return __compiletime_strlen(str); +} + +static void control_flow_split_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); +} + +#define KUNIT_EXPECT_BOS(test, p, expected, name) \ + KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ + expected, \ + "__alloc_size() not working with __bos on " name "\n") + +#if !__has_builtin(__builtin_dynamic_object_size) +#define KUNIT_EXPECT_BDOS(test, p, expected, name) \ + /* Silence "unused variable 'expected'" warning. */ \ + KUNIT_EXPECT_EQ(test, expected, expected) +#else +#define KUNIT_EXPECT_BDOS(test, p, expected, name) \ + KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ + expected, \ + "__alloc_size() not working with __bdos on " name "\n") +#endif + +/* If the execpted size is a constant value, __bos can see it. */ +#define check_const(_expected, alloc, free) do { \ + size_t expected = (_expected); \ + void *p = alloc; \ + KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ + KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ + KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ + free; \ +} while (0) + +/* If the execpted size is NOT a constant value, __bos CANNOT see it. */ +#define check_dynamic(_expected, alloc, free) do { \ + size_t expected = (_expected); \ + void *p = alloc; \ + KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ + KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ + KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ + free; \ +} while (0) + +/* Assortment of constant-value kinda-edge cases. */ +#define CONST_TEST_BODY(TEST_alloc) do { \ + /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ + if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ + TEST_alloc(check_const, 0, 0); \ + TEST_alloc(check_const, 1, 1); \ + TEST_alloc(check_const, 128, 128); \ + TEST_alloc(check_const, 1023, 1023); \ + TEST_alloc(check_const, 1025, 1025); \ + TEST_alloc(check_const, 4096, 4096); \ + TEST_alloc(check_const, 4097, 4097); \ +} while (0) + +static volatile size_t zero_size; +static volatile size_t unknown_size = 50; + +#if !__has_builtin(__builtin_dynamic_object_size) +#define DYNAMIC_TEST_BODY(TEST_alloc) \ + kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") +#else +#define DYNAMIC_TEST_BODY(TEST_alloc) do { \ + size_t size = unknown_size; \ + \ + /* \ + * Expected size is "size" in each test, before it is then \ + * internally incremented in each test. Requires we disable \ + * -Wunsequenced. \ + */ \ + TEST_alloc(check_dynamic, size, size++); \ + /* Make sure incrementing actually happened. */ \ + KUNIT_EXPECT_NE(test, size, unknown_size); \ +} while (0) +#endif + +#define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ +static void alloc_size_##allocator##_const_test(struct kunit *test) \ +{ \ + CONST_TEST_BODY(TEST_##allocator); \ +} \ +static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \ +{ \ + DYNAMIC_TEST_BODY(TEST_##allocator); \ +} + +#define TEST_kmalloc(checker, expected_size, alloc_size) do { \ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ + void *orig; \ + size_t len; \ + \ + checker(expected_size, kmalloc(alloc_size, gfp), \ + kfree(p)); \ + checker(expected_size, \ + kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, kzalloc(alloc_size, gfp), \ + kfree(p)); \ + checker(expected_size, \ + kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, kcalloc(1, alloc_size, gfp), \ + kfree(p)); \ + checker(expected_size, kcalloc(alloc_size, 1, gfp), \ + kfree(p)); \ + checker(expected_size, \ + kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, \ + kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ + kfree(p)); \ + checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ + kfree(p)); \ + checker(expected_size, \ + kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, \ + kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + checker(expected_size, __kmalloc(alloc_size, gfp), \ + kfree(p)); \ + checker(expected_size, \ + __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ + kfree(p)); \ + \ + orig = kmalloc(alloc_size, gfp); \ + KUNIT_EXPECT_TRUE(test, orig != NULL); \ + checker((expected_size) * 2, \ + krealloc(orig, (alloc_size) * 2, gfp), \ + kfree(p)); \ + orig = kmalloc(alloc_size, gfp); \ + KUNIT_EXPECT_TRUE(test, orig != NULL); \ + checker((expected_size) * 2, \ + krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ + kfree(p)); \ + orig = kmalloc(alloc_size, gfp); \ + KUNIT_EXPECT_TRUE(test, orig != NULL); \ + checker((expected_size) * 2, \ + krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ + kfree(p)); \ + \ + len = 11; \ + /* Using memdup() with fixed size, so force unknown length. */ \ + if (!__builtin_constant_p(expected_size)) \ + len += zero_size; \ + checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ +} while (0) +DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) + +/* Sizes are in pages, not bytes. */ +#define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ + checker((expected_pages) * PAGE_SIZE, \ + vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ +} while (0) +DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) + +/* Sizes are in pages (and open-coded for side-effects), not bytes. */ +#define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ + size_t prev_size; \ + void *orig; \ + \ + checker((expected_pages) * PAGE_SIZE, \ + kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ + vfree(p)); \ + checker((expected_pages) * PAGE_SIZE, \ + kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ + vfree(p)); \ + \ + prev_size = (expected_pages) * PAGE_SIZE; \ + orig = kvmalloc(prev_size, gfp); \ + KUNIT_EXPECT_TRUE(test, orig != NULL); \ + checker(((expected_pages) * PAGE_SIZE) * 2, \ + kvrealloc(orig, prev_size, \ + ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ + kvfree(p)); \ +} while (0) +DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) + +#define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ + const char dev_name[] = "fortify-test"; \ + struct device *dev; \ + void *orig; \ + size_t len; \ + \ + /* Create dummy device for devm_kmalloc()-family tests. */ \ + dev = root_device_register(dev_name); \ + KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ + "Cannot register test device\n"); \ + \ + checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ + devm_kfree(dev, p)); \ + checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ + devm_kfree(dev, p)); \ + checker(expected_size, \ + devm_kmalloc_array(dev, 1, alloc_size, gfp), \ + devm_kfree(dev, p)); \ + checker(expected_size, \ + devm_kmalloc_array(dev, alloc_size, 1, gfp), \ + devm_kfree(dev, p)); \ + checker(expected_size, \ + devm_kcalloc(dev, 1, alloc_size, gfp), \ + devm_kfree(dev, p)); \ + checker(expected_size, \ + devm_kcalloc(dev, alloc_size, 1, gfp), \ + devm_kfree(dev, p)); \ + \ + orig = devm_kmalloc(dev, alloc_size, gfp); \ + KUNIT_EXPECT_TRUE(test, orig != NULL); \ + checker((expected_size) * 2, \ + devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ + devm_kfree(dev, p)); \ + \ + len = 4; \ + /* Using memdup() with fixed size, so force unknown length. */ \ + if (!__builtin_constant_p(expected_size)) \ + len += zero_size; \ + checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ + devm_kfree(dev, p)); \ + \ + device_unregister(dev); \ +} while (0) +DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) + +static struct kunit_case fortify_test_cases[] = { + KUNIT_CASE(known_sizes_test), + KUNIT_CASE(control_flow_split_test), + KUNIT_CASE(alloc_size_kmalloc_const_test), + KUNIT_CASE(alloc_size_kmalloc_dynamic_test), + KUNIT_CASE(alloc_size_vmalloc_const_test), + KUNIT_CASE(alloc_size_vmalloc_dynamic_test), + KUNIT_CASE(alloc_size_kvmalloc_const_test), + KUNIT_CASE(alloc_size_kvmalloc_dynamic_test), + KUNIT_CASE(alloc_size_devm_kmalloc_const_test), + KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test), + {} +}; + +static struct kunit_suite fortify_test_suite = { + .name = "fortify", + .test_cases = fortify_test_cases, +}; + +kunit_test_suite(fortify_test_suite); + +MODULE_LICENSE("GPL"); |