[PATCH 03/32] flex_array: Add Kunit tests

Kees Cook
2022-05-04T01:52:10Z

Add tests for the new flexible array structure helpers. These can be run
with:

make ARCH=um mrproper
./tools/testing/kunit/kunit.py config
./tools/testing/kunit/kunit.py run flex_array

Cc: David Gow <davidgow@google.com>
Cc: kunit-dev@googlegroups.com
Signed-off-by: Kees Cook <keescook@chromium.org>
---
lib/Kconfig.debug | 12 +-
lib/Makefile | 1 +
lib/flex_array_kunit.c | 523 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 531 insertions(+), 5 deletions(-)
create mode 100644 lib/flex_array_kunit.c

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 9077bb38bc93..8bae6b169c50 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2551,11 +2551,6 @@ config OVERFLOW_KUNIT_TEST
Builds unit tests for the check_*_overflow(), size_*(), allocation, and
related functions.

- For more information on KUnit and unit tests in general please refer
- to the KUnit documentation in Documentation/dev-tools/kunit/.
-
- If unsure, say N.
-
config STACKINIT_KUNIT_TEST
tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
depends on KUNIT
@@ -2567,6 +2562,13 @@ config STACKINIT_KUNIT_TEST
CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.

+config FLEX_ARRAY_KUNIT_TEST
+ tristate "Test flex_*() family of helper functions at runtime" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Builds unit tests for flexible array copy helper functions.
+
config TEST_UDELAY
tristate "udelay test driver"
help
diff --git a/lib/Makefile b/lib/Makefile
index 6b9ffc1bd1ee..9884318db330 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -366,6 +366,7 @@ obj-$(CONFIG_MEMCPY_KUNIT_TEST) += memcpy_kunit.o
obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o
CFLAGS_stackinit_kunit.o += $(call cc-disable-warning, switch-unreachable)
obj-$(CONFIG_STACKINIT_KUNIT_TEST) += stackinit_kunit.o
+obj-$(CONFIG_FLEX_ARRAY_KUNIT_TEST) += flex_array_kunit.o

obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o

diff --git a/lib/flex_array_kunit.c b/lib/flex_array_kunit.c
new file mode 100644
index 000000000000..48bee88945b4
--- /dev/null
+++ b/lib/flex_array_kunit.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for flex_*() array manipulation helpers.
+ */
+#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/flex_array.h>
+
+#define COMPARE_STRUCTS(STRUCT_A, STRUCT_B) do { \
+ STRUCT_A *ptr_A; \
+ STRUCT_B *ptr_B; \
+ int rc; \
+ size_t size_A, size_B; \
+ \
+ /* matching types for flex array elements and count */ \
+ KUNIT_EXPECT_EQ(test, sizeof(*ptr_A), sizeof(*ptr_B)); \
+ KUNIT_EXPECT_TRUE(test, __same_type(*ptr_A->data, \
+ *ptr_B->__flex_array_elements)); \
+ KUNIT_EXPECT_TRUE(test, __same_type(ptr_A->datalen, \
+ ptr_B->__flex_array_elements_count)); \
+ KUNIT_EXPECT_EQ(test, sizeof(*ptr_A->data), \
+ sizeof(*ptr_B->__flex_array_elements)); \
+ KUNIT_EXPECT_EQ(test, offsetof(typeof(*ptr_A), data), \
+ offsetof(typeof(*ptr_B), \
+ __flex_array_elements)); \
+ KUNIT_EXPECT_EQ(test, offsetof(typeof(*ptr_A), datalen), \
+ offsetof(typeof(*ptr_B), \
+ __flex_array_elements_count)); \
+ \
+ /* struct_size() vs __fas_bytes() */ \
+ size_A = struct_size(ptr_A, data, 13); \
+ rc = __fas_bytes(ptr_B, __flex_array_elements, \
+ __flex_array_elements_count, 13, &size_B); \
+ KUNIT_EXPECT_EQ(test, rc, 0); \
+ KUNIT_EXPECT_EQ(test, size_A, size_B); \
+ \
+ /* flex_array_size() vs __fas_elements_bytes() */ \
+ size_A = flex_array_size(ptr_A, data, 13); \
+ rc = __fas_elements_bytes(ptr_B, __flex_array_elements, \
+ __flex_array_elements_count, 13, &size_B); \
+ KUNIT_EXPECT_EQ(test, rc, 0); \
+ KUNIT_EXPECT_EQ(test, size_A, size_B); \
+ \
+ KUNIT_EXPECT_EQ(test, sizeof(*ptr_A) + size_A, \
+ offsetof(typeof(*ptr_A), data) + \
+ (sizeof(*ptr_A->data) * 13)); \
+ KUNIT_EXPECT_EQ(test, sizeof(*ptr_B) + size_B, \
+ offsetof(typeof(*ptr_B), \
+ __flex_array_elements) + \
+ (sizeof(*ptr_B->__flex_array_elements) * \
+ 13)); \
+} while (0)
+
+struct normal {
+ size_t datalen;
+ u32 data[];
+};
+
+struct decl_normal {
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(size_t, datalen);
+ DECLARE_FLEX_ARRAY_ELEMENTS(u32, data);
+};
+
+struct aligned {
+ unsigned short datalen;
+ char data[] __aligned(__alignof__(u64));
+};
+
+struct decl_aligned {
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(unsigned short, datalen);
+ DECLARE_FLEX_ARRAY_ELEMENTS(char, data) __aligned(__alignof__(u64));
+};
+
+static void struct_test(struct kunit *test)
+{
+ COMPARE_STRUCTS(struct normal, struct decl_normal);
+ COMPARE_STRUCTS(struct aligned, struct decl_aligned);
+}
+
+/* Flexible array structure with internal padding. */
+struct flex_cpy_obj {
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u8, count);
+ unsigned long empty;
+ char induce_padding;
+ /* padding ends up here */
+ unsigned long after_padding;
+ DECLARE_FLEX_ARRAY_ELEMENTS(u32, flex);
+};
+
+/* Encapsulating flexible array structure. */
+struct flex_dup_obj {
+ unsigned long flags;
+ int junk;
+ struct flex_cpy_obj fas;
+};
+
+/* Flexible array struct of only bytes. */
+struct tiny_flex {
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u8, count);
+ DECLARE_FLEX_ARRAY_ELEMENTS(u8, byte_array);
+};
+
+#define CHECK_COPY(ptr) do { \
+ typeof(*(ptr)) *_cc_dst = (ptr); \
+ KUNIT_EXPECT_EQ(test, _cc_dst->induce_padding, 0); \
+ memcpy(&padding, &_cc_dst->induce_padding + sizeof(_cc_dst->induce_padding), \
+ sizeof(padding)); \
+ /* Padding should be zero too. */ \
+ KUNIT_EXPECT_EQ(test, padding, 0); \
+ KUNIT_EXPECT_EQ(test, src->count, _cc_dst->count); \
+ KUNIT_EXPECT_EQ(test, _cc_dst->count, TEST_TARGET); \
+ for (i = 0; i < _cc_dst->count - 1; i++) { \
+ /* 'A' is 0x41, and here repeated in a u32. */ \
+ KUNIT_EXPECT_EQ(test, _cc_dst->flex[i], 0x41414141); \
+ } \
+ /* Last item should be different. */ \
+ KUNIT_EXPECT_EQ(test, _cc_dst->flex[_cc_dst->count - 1], 0x14141414); \
+} while (0)
+
+/* Test copying from one flexible array struct into another. */
+static void flex_cpy_test(struct kunit *test)
+{
+#define TEST_BOUNDS 13
+#define TEST_TARGET 12
+#define TEST_SMALL 10
+ struct flex_cpy_obj *src, *dst;
+ unsigned long padding;
+ int i, rc;
+
+ /* Prepare open-coded source. */
+ src = kzalloc(struct_size(src, flex, TEST_BOUNDS), GFP_KERNEL);
+ src->count = TEST_BOUNDS;
+ memset(src->flex, 'A', flex_array_size(src, flex, TEST_BOUNDS));
+ src->flex[src->count - 2] = 0x14141414;
+ src->flex[src->count - 1] = 0x24242424;
+
+ /* Prepare open-coded destination, alloc only. */
+ dst = kzalloc(struct_size(src, flex, TEST_BOUNDS), GFP_KERNEL);
+ /* Pre-fill with 0xFE marker. */
+ memset(dst, 0xFE, struct_size(src, flex, TEST_BOUNDS));
+ /* Pretend we're 1 element smaller. */
+ dst->count = TEST_TARGET;
+
+ /* Pretend to match the target destination size. */
+ src->count = TEST_TARGET;
+
+ rc = flex_cpy(dst, src);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ CHECK_COPY(dst);
+ /* Item past last copied item is unchanged from initial memset. */
+ KUNIT_EXPECT_EQ(test, dst->flex[dst->count], 0xFEFEFEFE);
+
+ /* Now trip overflow, and verify we didn't clobber beyond end. */
+ src->count = TEST_BOUNDS;
+ rc = flex_cpy(dst, src);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Item past last copied item is unchanged from initial memset. */
+ KUNIT_EXPECT_EQ(test, dst->flex[dst->count], 0xFEFEFEFE);
+
+ /* Reset destination contents. */
+ memset(dst, 0xFD, struct_size(src, flex, TEST_BOUNDS));
+ dst->count = TEST_TARGET;
+
+ /* Copy less than max. */
+ src->count = TEST_SMALL;
+ rc = flex_cpy(dst, src);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ /* Verify count was adjusted. */
+ KUNIT_EXPECT_EQ(test, dst->count, TEST_SMALL);
+ /* Verify element beyond src size was wiped. */
+ KUNIT_EXPECT_EQ(test, dst->flex[TEST_SMALL], 0);
+ /* Verify element beyond original dst size was untouched. */
+ KUNIT_EXPECT_EQ(test, dst->flex[TEST_TARGET], 0xFDFDFDFD);
+
+ kfree(dst);
+ kfree(src);
+#undef TEST_BOUNDS
+#undef TEST_TARGET
+#undef TEST_SMALL
+}
+
+static void flex_dup_test(struct kunit *test)
+{
+#define TEST_TARGET 12
+ struct flex_cpy_obj *src, *dst = NULL, **null = NULL;
+ struct flex_dup_obj *encap = NULL;
+ unsigned long padding;
+ int i, rc;
+
+ /* Prepare open-coded source. */
+ src = kzalloc(struct_size(src, flex, TEST_TARGET), GFP_KERNEL);
+ src->count = TEST_TARGET;
+ memset(src->flex, 'A', flex_array_size(src, flex, TEST_TARGET));
+ src->flex[src->count - 1] = 0x14141414;
+
+ /* Reject NULL @alloc. */
+ rc = flex_dup(null, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+
+ /* Check good copy. */
+ rc = flex_dup(&dst, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_ASSERT_TRUE(test, dst != NULL);
+ CHECK_COPY(dst);
+
+ /* Reject non-NULL *@alloc. */
+ rc = flex_dup(&dst, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+
+ kfree(dst);
+
+ /* Check good encap copy. */
+ rc = __flex_dup(&encap, .fas, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_ASSERT_TRUE(test, dst != NULL);
+ CHECK_COPY(&encap->fas);
+ /* Check that items external to "fas" are zero. */
+ KUNIT_EXPECT_EQ(test, encap->flags, 0);
+ KUNIT_EXPECT_EQ(test, encap->junk, 0);
+ kfree(encap);
+#undef MAGIC_WORD
+#undef TEST_TARGET
+}
+
+static void mem_to_flex_test(struct kunit *test)
+{
+#define TEST_TARGET 9
+#define TEST_MAX U8_MAX
+#define MAGIC_WORD 0x03030303
+ u8 magic_byte = MAGIC_WORD & 0xff;
+ struct flex_cpy_obj *dst;
+ size_t big = (size_t)INT_MAX + 1;
+ char small[] = "Hello";
+ char *src;
+ u32 src_len;
+ int rc;
+
+ /* Open coded allocations, 1 larger than actually used. */
+ src_len = flex_array_size(dst, flex, TEST_MAX + 1);
+ src = kzalloc(src_len, GFP_KERNEL);
+ dst = kzalloc(struct_size(dst, flex, TEST_MAX + 1), GFP_KERNEL);
+ dst->count = TEST_TARGET;
+
+ /* Fill source. */
+ memset(src, magic_byte, src_len);
+
+ /* Short copy is fine. */
+ KUNIT_EXPECT_EQ(test, dst->flex[0], 0);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+ rc = mem_to_flex(dst, src, 1);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_EXPECT_EQ(test, dst->count, 1);
+ KUNIT_EXPECT_EQ(test, dst->after_padding, 0);
+ KUNIT_EXPECT_EQ(test, dst->flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+ dst->count = TEST_TARGET;
+
+ /* Reject negative elements count. */
+ rc = mem_to_flex(dst, small, -1);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure dst is unchanged. */
+ KUNIT_EXPECT_EQ(test, dst->flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+
+ /* Reject compile-time read overflow. */
+ rc = mem_to_flex(dst, small, 20);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure dst is unchanged. */
+ KUNIT_EXPECT_EQ(test, dst->flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+
+ /* Reject giant buffer source. */
+ rc = mem_to_flex(dst, small, big);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure dst is unchanged. */
+ KUNIT_EXPECT_EQ(test, dst->flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+
+ /* Copy beyond storage size is rejected. */
+ dst->count = TEST_MAX;
+ KUNIT_EXPECT_EQ(test, dst->flex[TEST_MAX - 1], 0);
+ KUNIT_EXPECT_EQ(test, dst->flex[TEST_MAX], 0);
+ rc = mem_to_flex(dst, src, TEST_MAX + 1);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure dst is unchanged. */
+ KUNIT_EXPECT_EQ(test, dst->flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, dst->flex[1], 0);
+
+ kfree(dst);
+ kfree(src);
+#undef MAGIC_WORD
+#undef TEST_MAX
+#undef TEST_TARGET
+}
+
+static void mem_to_flex_dup_test(struct kunit *test)
+{
+#define ELEMENTS_COUNT 259
+#define MAGIC_WORD 0xABABABAB
+ u8 magic_byte = MAGIC_WORD & 0xff;
+ struct flex_dup_obj *obj = NULL;
+ struct tiny_flex *tiny = NULL, **null = NULL;
+ size_t src_len, count, big = (size_t)INT_MAX + 1;
+ char small[] = "Hello";
+ u8 *src;
+ int rc;
+
+ src_len = struct_size(tiny, byte_array, ELEMENTS_COUNT);
+ src = kzalloc(src_len, GFP_KERNEL);
+ KUNIT_ASSERT_TRUE(test, src != NULL);
+ /* Fill with bytes. */
+ memset(src, magic_byte, src_len);
+ KUNIT_EXPECT_EQ(test, src[0], magic_byte);
+ KUNIT_EXPECT_EQ(test, src[src_len / 2], magic_byte);
+ KUNIT_EXPECT_EQ(test, src[src_len - 1], magic_byte);
+
+ /* Reject storage exceeding elements_count type. */
+ count = ELEMENTS_COUNT;
+ rc = mem_to_flex_dup(&tiny, src, count, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ KUNIT_EXPECT_TRUE(test, tiny == NULL);
+
+ /* Reject negative elements count. */
+ rc = mem_to_flex_dup(&tiny, src, -1, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ KUNIT_EXPECT_TRUE(test, tiny == NULL);
+
+ /* Reject compile-time read overflow. */
+ rc = mem_to_flex_dup(&tiny, small, 20, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ KUNIT_EXPECT_TRUE(test, tiny == NULL);
+
+ /* Reject giant buffer source. */
+ rc = mem_to_flex_dup(&tiny, small, big, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ KUNIT_EXPECT_TRUE(test, tiny == NULL);
+
+ /* Reject NULL @alloc. */
+ rc = mem_to_flex_dup(null, src, count, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+
+ /* Allow reasonable count.*/
+ count = ELEMENTS_COUNT / 2;
+ rc = mem_to_flex_dup(&tiny, src, count, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_ASSERT_TRUE(test, tiny != NULL);
+ /* Spot check the copy happened. */
+ KUNIT_EXPECT_EQ(test, tiny->count, count);
+ KUNIT_EXPECT_EQ(test, tiny->byte_array[0], magic_byte);
+ KUNIT_EXPECT_EQ(test, tiny->byte_array[count / 2], magic_byte);
+ KUNIT_EXPECT_EQ(test, tiny->byte_array[count - 1], magic_byte);
+
+ /* Reject non-NULL *@alloc. */
+ rc = mem_to_flex_dup(&tiny, src, count, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+ kfree(tiny);
+
+ /* Works with encapsulation too. */
+ count = ELEMENTS_COUNT / 10;
+ rc = __mem_to_flex_dup(&obj, .fas, src, count, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_ASSERT_TRUE(test, obj != NULL);
+ /* Spot check the copy happened. */
+ KUNIT_EXPECT_EQ(test, obj->fas.count, count);
+ KUNIT_EXPECT_EQ(test, obj->fas.after_padding, 0);
+ KUNIT_EXPECT_EQ(test, obj->fas.flex[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, obj->fas.flex[count / 2], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, obj->fas.flex[count - 1], MAGIC_WORD);
+ /* Check members before flexible array struct are zero. */
+ KUNIT_EXPECT_EQ(test, obj->flags, 0);
+ KUNIT_EXPECT_EQ(test, obj->junk, 0);
+ kfree(obj);
+#undef MAGIC_WORD
+#undef ELEMENTS_COUNT
+}
+
+static void flex_to_mem_test(struct kunit *test)
+{
+#define ELEMENTS_COUNT 200
+#define MAGIC_WORD 0xF1F2F3F4
+ struct flex_cpy_obj *src;
+ typeof(*src->flex) *cast;
+ size_t src_len = struct_size(src, flex, ELEMENTS_COUNT);
+ size_t copy_len = flex_array_size(src, flex, ELEMENTS_COUNT);
+ int i, rc;
+ size_t bytes = 0;
+ u8 too_small;
+ u8 *dst;
+
+ /* Create a filled flexible array struct. */
+ src = kzalloc(src_len, GFP_KERNEL);
+ KUNIT_ASSERT_TRUE(test, src != NULL);
+ src->count = ELEMENTS_COUNT;
+ src->after_padding = 13;
+ for (i = 0; i < ELEMENTS_COUNT; i++)
+ src->flex[i] = MAGIC_WORD;
+
+ /* Over-allocate space to do past-src_len checking. */
+ dst = kzalloc(src_len * 2, GFP_KERNEL);
+ KUNIT_ASSERT_TRUE(test, dst != NULL);
+ cast = (void *)dst;
+
+ /* Fail if dst is too small. */
+ rc = flex_to_mem(dst, copy_len - 1, src, &bytes);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure nothing was copied. */
+ KUNIT_EXPECT_EQ(test, bytes, 0);
+ KUNIT_EXPECT_EQ(test, cast[0], 0);
+
+ /* Fail if type too small to hold size of copy. */
+ KUNIT_EXPECT_GT(test, copy_len, type_max(typeof(too_small)));
+ rc = flex_to_mem(dst, copy_len, src, &too_small);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ /* Make sure nothing was copied. */
+ KUNIT_EXPECT_EQ(test, bytes, 0);
+ KUNIT_EXPECT_EQ(test, cast[0], 0);
+
+ /* Check good copy. */
+ rc = flex_to_mem(dst, copy_len, src, &bytes);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_EXPECT_EQ(test, bytes, copy_len);
+ /* Spot check the copy */
+ KUNIT_EXPECT_EQ(test, cast[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, cast[ELEMENTS_COUNT / 2], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, cast[ELEMENTS_COUNT - 1], MAGIC_WORD);
+ /* Make sure nothing was written after last element. */
+ KUNIT_EXPECT_EQ(test, cast[ELEMENTS_COUNT], 0);
+
+ kfree(dst);
+ kfree(src);
+#undef MAGIC_WORD
+#undef ELEMENTS_COUNT
+}
+
+static void flex_to_mem_dup_test(struct kunit *test)
+{
+#define ELEMENTS_COUNT 210
+#define MAGIC_WORD 0xF0F1F2F3
+ struct flex_dup_obj *obj, **null = NULL;
+ struct flex_cpy_obj *src;
+ typeof(*src->flex) *cast;
+ size_t obj_len = struct_size(obj, fas.flex, ELEMENTS_COUNT);
+ size_t src_len = struct_size(src, flex, ELEMENTS_COUNT);
+ size_t copy_len = flex_array_size(src, flex, ELEMENTS_COUNT);
+ int i, rc;
+ size_t bytes = 0;
+ u8 too_small = 0;
+ u8 *dst = NULL;
+
+ /* Create a filled flexible array struct. */
+ obj = kzalloc(obj_len, GFP_KERNEL);
+ KUNIT_ASSERT_TRUE(test, obj != NULL);
+ obj->fas.count = ELEMENTS_COUNT;
+ obj->fas.after_padding = 13;
+ for (i = 0; i < ELEMENTS_COUNT; i++)
+ obj->fas.flex[i] = MAGIC_WORD;
+ src = &obj->fas;
+
+ /* Fail if type too small to hold size of copy. */
+ KUNIT_EXPECT_GT(test, src_len, type_max(typeof(too_small)));
+ rc = flex_to_mem_dup(&dst, &too_small, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -E2BIG);
+ KUNIT_EXPECT_TRUE(test, dst == NULL);
+ KUNIT_EXPECT_EQ(test, too_small, 0);
+
+ /* Fail if @alloc_size is NULL. */
+ KUNIT_EXPECT_TRUE(test, dst == NULL);
+ rc = flex_to_mem_dup(&dst, dst, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+ KUNIT_EXPECT_TRUE(test, dst == NULL);
+
+ /* Fail if @alloc is NULL. */
+ rc = flex_to_mem_dup(null, &bytes, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+ KUNIT_EXPECT_TRUE(test, dst == NULL);
+ KUNIT_EXPECT_EQ(test, bytes, 0);
+
+ /* Check good copy. */
+ rc = flex_to_mem_dup(&dst, &bytes, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, 0);
+ KUNIT_EXPECT_TRUE(test, dst != NULL);
+ KUNIT_EXPECT_EQ(test, bytes, copy_len);
+ cast = (void *)dst;
+ /* Spot check the copy */
+ KUNIT_EXPECT_EQ(test, cast[0], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, cast[ELEMENTS_COUNT / 2], MAGIC_WORD);
+ KUNIT_EXPECT_EQ(test, cast[ELEMENTS_COUNT - 1], MAGIC_WORD);
+
+ /* Fail if *@alloc is non-NULL. */
+ bytes = 0;
+ rc = flex_to_mem_dup(&dst, &bytes, src, GFP_KERNEL);
+ KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+ KUNIT_EXPECT_EQ(test, bytes, 0);
+
+ kfree(dst);
+ kfree(obj);
+#undef MAGIC_WORD
+#undef ELEMENTS_COUNT
+}
+
+static struct kunit_case flex_array_test_cases[] = {
+ KUNIT_CASE(struct_test),
+ KUNIT_CASE(flex_cpy_test),
+ KUNIT_CASE(flex_dup_test),
+ KUNIT_CASE(mem_to_flex_test),
+ KUNIT_CASE(mem_to_flex_dup_test),
+ KUNIT_CASE(flex_to_mem_test),
+ KUNIT_CASE(flex_to_mem_dup_test),
+ {}
+};
+
+static struct kunit_suite flex_array_test_suite = {
+ .name = "flex_array",
+ .test_cases = flex_array_test_cases,
+};
+
+kunit_test_suite(flex_array_test_suite);
+
+MODULE_LICENSE("GPL");
--
2.32.0