[PATCH v2 33/63] lib: Introduce CONFIG_TEST_MEMCPY

Before changing anything about memcpy(), memmove(), and memset(), add run-time tests to check basic behaviors for any regressions.

Signed-off-by: Kees Cook keescook@chromium.org --- lib/Kconfig.debug | 7 ++ lib/Makefile | 1 + lib/test_memcpy.c | 264 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 272 insertions(+) create mode 100644 lib/test_memcpy.c

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 139d362daa32..db2e8ffa6049 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2476,6 +2476,13 @@ config RATIONAL_KUNIT_TEST

If unsure, say N.

+config MEMCPY_KUNIT_TEST + tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + Builds unit tests for memcpy(), memmove(), and memset() functions. + config TEST_UDELAY tristate "udelay test driver" help diff --git a/lib/Makefile b/lib/Makefile index bd17c2bf43e1..8a4c8bdb38a2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -77,6 +77,7 @@ obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o obj-$(CONFIG_TEST_LKM) += test_module.o obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o +obj-$(CONFIG_TEST_MEMCPY) += test_memcpy.o obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o obj-$(CONFIG_TEST_SORT) += test_sort.o obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o diff --git a/lib/test_memcpy.c b/lib/test_memcpy.c new file mode 100644 index 000000000000..be192b8e82b7 --- /dev/null +++ b/lib/test_memcpy.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for memcpy(), memmove(), and memset(). + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <kunit/test.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/vmalloc.h> + +struct some_bytes { + union { + u8 data[32]; + struct { + u32 one; + u16 two; + u8 three; + /* 1 byte hole */ + u32 four[4]; + }; + }; +}; + +#define check(instance, v) do { \ + int i; \ + BUILD_BUG_ON(sizeof(instance.data) != 32); \ + for (i = 0; i < sizeof(instance.data); i++) { \ + KUNIT_ASSERT_EQ_MSG(test, instance.data[i], v, \ + "line %d: '%s' not initialized to 0x%02x @ %d (saw 0x%02x)\n", \ + __LINE__, #instance, v, i, instance.data[i]); \ + } \ +} while (0) + +#define compare(name, one, two) do { \ + int i; \ + BUILD_BUG_ON(sizeof(one) != sizeof(two)); \ + for (i = 0; i < sizeof(one); i++) { \ + KUNIT_EXPECT_EQ_MSG(test, one.data[i], two.data[i], \ + "line %d: %s.data[%d] (0x%02x) != %s.data[%d] (0x%02x)\n", \ + __LINE__, #one, i, one.data[i], #two, i, two.data[i]); \ + } \ + kunit_info(test, "ok: " TEST_OP "() " name "\n"); \ +} while (0) + +static void memcpy_test(struct kunit *test) +{ +#define TEST_OP "memcpy" + struct some_bytes control = { + .data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes zero = { }; + struct some_bytes middle = { + .data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes three = { + .data = { 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes dest = { }; + int count; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x20); + check(zero, 0); + compare("static initializers", dest, zero); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memcpy(dest.data, zero.data, sizeof(dest.data)); + compare("complete overwrite", dest, zero); + + /* Verify middle overwrite. */ + dest = control; + memcpy(dest.data + 12, zero.data, 7); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + count = 1; + memcpy(ptr++, zero.data, count++); + ptr += 8; + memcpy(ptr++, zero.data, count++); + compare("argument side-effects", dest, three); +#undef TEST_OP +} + +static void memmove_test(struct kunit *test) +{ +#define TEST_OP "memmove" + struct some_bytes control = { + .data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes zero = { }; + struct some_bytes middle = { + .data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes five = { + .data = { 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x00, 0x00, 0x00, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes overlap = { + .data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes overlap_expected = { + .data = { 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x07, + 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes dest = { }; + int count; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x99); + check(zero, 0); + compare("static initializers", zero, dest); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memmove(dest.data, zero.data, sizeof(dest.data)); + compare("complete overwrite", dest, zero); + + /* Verify middle overwrite. */ + dest = control; + memmove(dest.data + 12, zero.data, 7); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + count = 2; + memmove(ptr++, zero.data, count++); + ptr += 9; + memmove(ptr++, zero.data, count++); + compare("argument side-effects", dest, five); + + /* Verify overlapping overwrite is correct. */ + ptr = &overlap.data[2]; + memmove(ptr, overlap.data, 5); + compare("overlapping write", overlap, overlap_expected); +#undef TEST_OP +} + +static void memset_test(struct kunit *test) +{ +#define TEST_OP "memset" + struct some_bytes control = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes complete = { + .data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + }, + }; + struct some_bytes middle = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x31, + 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, + 0x31, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes three = { + .data = { 0x60, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x61, 0x61, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes dest = { }; + int count, value; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x30); + check(dest, 0); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memset(dest.data, 0xff, sizeof(dest.data)); + compare("complete overwrite", dest, complete); + + /* Verify middle overwrite. */ + dest = control; + memset(dest.data + 4, 0x31, 16); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + value = 0x60; + count = 1; + memset(ptr++, value++, count++); + ptr += 8; + memset(ptr++, value++, count++); + compare("argument side-effects", dest, three); +#undef TEST_OP +} + +static struct kunit_case memcpy_test_cases[] = { + KUNIT_CASE(memset_test), + KUNIT_CASE(memcpy_test), + KUNIT_CASE(memmove_test), + {} +}; + +static struct kunit_suite memcpy_test_suite = { + .name = "memcpy-test", + .test_cases = memcpy_test_cases, +}; +kunit_test_suite(memcpy_test_suite); + +MODULE_LICENSE("GPL");