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Message-ID: <e384af13-ca63-4847-a84d-5957abd5d903@gmail.com>
Date: Wed, 29 May 2024 13:17:35 +0100
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Subject: Re: [PATCH 2/2] usercopy: Convert test_user_copy to KUnit test
To: Kees Cook <keescook@chromium.org>, Mark Rutland <mark.rutland@arm.com>
Cc: Vitor Massaru Iha <vitor@massaru.org>,
 Brendan Higgins <brendan.higgins@linux.dev>, David Gow
 <davidgow@google.com>, Rae Moar <rmoar@google.com>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>, linux-kernel@vger.kernel.org,
 linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com,
 linux-hardening@vger.kernel.org
References: <20240519190422.work.715-kees@kernel.org>
 <20240519191254.651865-2-keescook@chromium.org>
Content-Language: en-US
From: Ivan Orlov <ivan.orlov0322@gmail.com>
In-Reply-To: <20240519191254.651865-2-keescook@chromium.org>
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On 5/19/24 20:12, Kees Cook wrote:
> Convert the runtime tests of hardened usercopy to standard KUnit tests.
> 
> Co-developed-by: Vitor Massaru Iha <vitor@massaru.org>
> Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
> Link: https://lore.kernel.org/r/20200721174654.72132-1-vitor@massaru.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---

Hi Kees,

It looks great, just a couple of minor comments below.

>   MAINTAINERS                                |   1 +
>   lib/Kconfig.debug                          |  21 +-
>   lib/Makefile                               |   2 +-
>   lib/{test_user_copy.c => usercopy_kunit.c} | 252 ++++++++++-----------
>   4 files changed, 133 insertions(+), 143 deletions(-)
>   rename lib/{test_user_copy.c => usercopy_kunit.c} (52%)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7c121493f43d..73995b807e5a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11761,6 +11761,7 @@ F:	arch/*/configs/hardening.config
>   F:	include/linux/overflow.h
>   F:	include/linux/randomize_kstack.h
>   F:	kernel/configs/hardening.config
> +F:	lib/usercopy_kunit.c
>   F:	mm/usercopy.c
>   K:	\b(add|choose)_random_kstack_offset\b
>   K:	\b__check_(object_size|heap_object)\b
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c63a5fbf1f1c..fd974480aa45 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2460,18 +2460,6 @@ config TEST_VMALLOC
>   
>   	  If unsure, say N.
>   
> -config TEST_USER_COPY
> -	tristate "Test user/kernel boundary protections"
> -	depends on m
> -	help
> -	  This builds the "test_user_copy" module that runs sanity checks
> -	  on the copy_to/from_user infrastructure, making sure basic
> -	  user/kernel boundary testing is working. If it fails to load,
> -	  a regression has been detected in the user/kernel memory boundary
> -	  protections.
> -
> -	  If unsure, say N.
> -
>   config TEST_BPF
>   	tristate "Test BPF filter functionality"
>   	depends on m && NET
> @@ -2779,6 +2767,15 @@ config SIPHASH_KUNIT_TEST
>   	  This is intended to help people writing architecture-specific
>   	  optimized versions.  If unsure, say N.
>   
> +config USERCOPY_KUNIT_TEST
> +	tristate "KUnit Test for user/kernel boundary protections"
> +	depends on KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  This builds the "usercopy_kunit" module that runs sanity checks
> +	  on the copy_to/from_user infrastructure, making sure basic
> +	  user/kernel boundary testing is working.
> +
>   config TEST_UDELAY
>   	tristate "udelay test driver"
>   	help
> diff --git a/lib/Makefile b/lib/Makefile
> index ffc6b2341b45..6287bd6be5d7 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -78,7 +78,6 @@ obj-$(CONFIG_TEST_LKM) += test_module.o
>   obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
>   obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
>   obj-$(CONFIG_TEST_SORT) += test_sort.o
> -obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
>   obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
>   obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
>   obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
> @@ -406,6 +405,7 @@ obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
>   obj-$(CONFIG_STRCAT_KUNIT_TEST) += strcat_kunit.o
>   obj-$(CONFIG_STRSCPY_KUNIT_TEST) += strscpy_kunit.o
>   obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
> +obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
>   
>   obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
>   
> diff --git a/lib/test_user_copy.c b/lib/usercopy_kunit.c
> similarity index 52%
> rename from lib/test_user_copy.c
> rename to lib/usercopy_kunit.c
> index 5ff04d8fe971..515df08b3190 100644
> --- a/lib/test_user_copy.c
> +++ b/lib/usercopy_kunit.c
> @@ -15,7 +15,7 @@
>   #include <linux/sched.h>
>   #include <linux/slab.h>
>   #include <linux/uaccess.h>
> -#include <linux/vmalloc.h>
> +#include <kunit/test.h>
>   
>   /*
>    * Several 32-bit architectures support 64-bit {get,put}_user() calls.
> @@ -31,11 +31,17 @@
>   # define TEST_U64
>   #endif
>   
> +struct usercopy_test_priv {
> +	char *kmem;
> +	char __user *umem;
> +	size_t size;
> +};
> +
>   #define test(condition, msg, ...)					\
>   ({									\
>   	int cond = (condition);						\
>   	if (cond)							\
> -		pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__);	\
> +		KUNIT_EXPECT_FALSE_MSG(test, cond, msg, ##__VA_ARGS__);	\
>   	cond;								\
>   })
It looks like the 'test' macro is not used anymore, so probably it 
should be removed.

>   
> @@ -44,13 +50,16 @@ static bool is_zeroed(void *from, size_t size)
>   	return memchr_inv(from, 0x0, size) == NULL;
>   }
>   
> -static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
> +/* Test usage of check_nonzero_user(). */
> +static void usercopy_test_check_nonzero_user(struct kunit *test)
>   {
> -	int ret = 0;
>   	size_t start, end, i, zero_start, zero_end;
> +	struct usercopy_test_priv *priv = test->priv;
> +	char __user *umem = priv->umem;
> +	char *kmem = priv->kmem;
> +	size_t size = priv->size;
>   
> -	if (test(size < 2 * PAGE_SIZE, "buffer too small"))
> -		return -EINVAL;
> +	KUNIT_ASSERT_GE_MSG(test, size, 2 * PAGE_SIZE, "buffer too small");
>   
>   	/*
>   	 * We want to cross a page boundary to exercise the code more
> @@ -84,8 +93,8 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
>   	for (i = zero_end; i < size; i += 2)
>   		kmem[i] = 0xff;
>   
> -	ret |= test(copy_to_user(umem, kmem, size),
> -		    "legitimate copy_to_user failed");
> +	KUNIT_EXPECT_EQ_MSG(test, copy_to_user(umem, kmem, size), 0,
> +		"legitimate copy_to_user failed");
>   
>   	for (start = 0; start <= size; start++) {
>   		for (end = start; end <= size; end++) {
> @@ -93,35 +102,32 @@ static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
>   			int retval = check_zeroed_user(umem + start, len);
>   			int expected = is_zeroed(kmem + start, len);
>   
> -			ret |= test(retval != expected,
> -				    "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)",
> -				    retval, expected, start, end);
> +			KUNIT_EXPECT_EQ_MSG(test, retval, expected,
> +				"check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)",
> +				retval, expected, start, end);
>   		}
>   	}
> -
> -	return ret;
>   }
>   
> -static int test_copy_struct_from_user(char *kmem, char __user *umem,
> -				      size_t size)
> +/* Test usage of copy_struct_from_user(). */
> +static void usercopy_test_copy_struct_from_user(struct kunit *test)
>   {
> -	int ret = 0;
>   	char *umem_src = NULL, *expected = NULL;
> +	struct usercopy_test_priv *priv = test->priv;
> +	char __user *umem = priv->umem;
> +	char *kmem = priv->kmem;
> +	size_t size = priv->size;
>   	size_t ksize, usize;
>   
> -	umem_src = kmalloc(size, GFP_KERNEL);
> -	ret = test(umem_src == NULL, "kmalloc failed");
> -	if (ret)
> -		goto out_free;
> +	umem_src = kunit_kmalloc(test, size, GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, umem_src);
>   
> -	expected = kmalloc(size, GFP_KERNEL);
> -	ret = test(expected == NULL, "kmalloc failed");
> -	if (ret)
> -		goto out_free;
> +	expected = kunit_kmalloc(test, size, GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected);
>   
>   	/* Fill umem with a fixed byte pattern. */
>   	memset(umem_src, 0x3e, size);
> -	ret |= test(copy_to_user(umem, umem_src, size),
> +	KUNIT_ASSERT_EQ_MSG(test, copy_to_user(umem, umem_src, size), 0,
>   		    "legitimate copy_to_user failed");
>   
>   	/* Check basic case -- (usize == ksize). */
> @@ -131,9 +137,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem,
>   	memcpy(expected, umem_src, ksize);
>   
>   	memset(kmem, 0x0, size);
> -	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
> +	KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
>   		    "copy_struct_from_user(usize == ksize) failed");
> -	ret |= test(memcmp(kmem, expected, ksize),
> +	KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0,
>   		    "copy_struct_from_user(usize == ksize) gives unexpected copy");
>   
>   	/* Old userspace case -- (usize < ksize). */
> @@ -144,9 +150,9 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem,
>   	memset(expected + usize, 0x0, ksize - usize);
>   
>   	memset(kmem, 0x0, size);
> -	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
> +	KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
>   		    "copy_struct_from_user(usize < ksize) failed");
> -	ret |= test(memcmp(kmem, expected, ksize),
> +	KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0,
>   		    "copy_struct_from_user(usize < ksize) gives unexpected copy");
>   
>   	/* New userspace (-E2BIG) case -- (usize > ksize). */
> @@ -154,7 +160,7 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem,
>   	usize = size;
>   
>   	memset(kmem, 0x0, size);
> -	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize) != -E2BIG,
> +	KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), -E2BIG,
>   		    "copy_struct_from_user(usize > ksize) didn't give E2BIG");
>   
>   	/* New userspace (success) case -- (usize > ksize). */
> @@ -162,78 +168,46 @@ static int test_copy_struct_from_user(char *kmem, char __user *umem,
>   	usize = size;
>   
>   	memcpy(expected, umem_src, ksize);
> -	ret |= test(clear_user(umem + ksize, usize - ksize),
> +	KUNIT_EXPECT_EQ_MSG(test, clear_user(umem + ksize, usize - ksize), 0,
>   		    "legitimate clear_user failed");
>   
>   	memset(kmem, 0x0, size);
> -	ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
> +	KUNIT_EXPECT_EQ_MSG(test, copy_struct_from_user(kmem, ksize, umem, usize), 0,
>   		    "copy_struct_from_user(usize > ksize) failed");
> -	ret |= test(memcmp(kmem, expected, ksize),
> +	KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem, expected, ksize), 0,
>   		    "copy_struct_from_user(usize > ksize) gives unexpected copy");
> -
> -out_free:
> -	kfree(expected);
> -	kfree(umem_src);
> -	return ret;
>   }
>   
> -static int __init test_user_copy_init(void)
> +/*
> + * Legitimate usage: none of these copies should fail.
> + */
> +static void usercopy_test_valid(struct kunit *test)
>   {
> -	int ret = 0;
> -	char *kmem;
> -	char __user *usermem;
> -	char *bad_usermem;
> -	unsigned long user_addr;
> -	u8 val_u8;
> -	u16 val_u16;
> -	u32 val_u32;
> -#ifdef TEST_U64
> -	u64 val_u64;
> -#endif
> -
> -	kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
> -	if (!kmem)
> -		return -ENOMEM;
> -
> -	user_addr = vm_mmap(NULL, 0, PAGE_SIZE * 2,
> -			    PROT_READ | PROT_WRITE | PROT_EXEC,
> -			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
> -	if (user_addr >= (unsigned long)(TASK_SIZE)) {
> -		pr_warn("Failed to allocate user memory\n");
> -		kfree(kmem);
> -		return -ENOMEM;
> -	}
> +	struct usercopy_test_priv *priv = test->priv;
> +	char __user *usermem = priv->umem;
> +	char *kmem = priv->kmem;
>   
> -	usermem = (char __user *)user_addr;
> -	bad_usermem = (char *)user_addr;
> -
> -	/*
> -	 * Legitimate usage: none of these copies should fail.
> -	 */
>   	memset(kmem, 0x3a, PAGE_SIZE * 2);
> -	ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE),
> -		    "legitimate copy_to_user failed");
> +	KUNIT_EXPECT_EQ_MSG(test, 0, copy_to_user(usermem, kmem, PAGE_SIZE),
> +	     "legitimate copy_to_user failed");
>   	memset(kmem, 0x0, PAGE_SIZE);
> -	ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE),
> -		    "legitimate copy_from_user failed");
> -	ret |= test(memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE),
> -		    "legitimate usercopy failed to copy data");
> -
> -#define test_legit(size, check)						  \
> -	do {								  \
> -		val_##size = check;					  \
> -		ret |= test(put_user(val_##size, (size __user *)usermem), \
> -		    "legitimate put_user (" #size ") failed");		  \
> -		val_##size = 0;						  \
> -		ret |= test(get_user(val_##size, (size __user *)usermem), \
> -		    "legitimate get_user (" #size ") failed");		  \
> -		ret |= test(val_##size != check,			  \
> -		    "legitimate get_user (" #size ") failed to do copy"); \
> -		if (val_##size != check) {				  \
> -			pr_info("0x%llx != 0x%llx\n",			  \
> -				(unsigned long long)val_##size,		  \
> -				(unsigned long long)check);		  \
> -		}							  \
> +	KUNIT_EXPECT_EQ_MSG(test, 0, copy_from_user(kmem, usermem, PAGE_SIZE),
> +	     "legitimate copy_from_user failed");
> +	KUNIT_EXPECT_EQ_MSG(test, 0, memcmp(kmem, kmem + PAGE_SIZE, PAGE_SIZE),
> +	     "legitimate usercopy failed to copy data");
> +
> +#define test_legit(size, check)						\
> +	do {								\
> +		size val_##size = (check);				\
> +		KUNIT_EXPECT_EQ_MSG(test, 0,				\
> +			put_user(val_##size, (size __user *)usermem),	\
> +			"legitimate put_user (" #size ") failed");	\
> +		val_##size = 0;						\
> +		KUNIT_EXPECT_EQ_MSG(test, 0,				\
> +			get_user(val_##size, (size __user *)usermem),	\
> +			"legitimate get_user (" #size ") failed");	\
> +		KUNIT_EXPECT_EQ_MSG(test, val_##size, check,		\
> +			"legitimate get_user (" #size ") failed to do copy"); \
>   	} while (0)
>   
>   	test_legit(u8,  0x5a);
> @@ -243,27 +217,29 @@ static int __init test_user_copy_init(void)
>   	test_legit(u64, 0x5a5b5c5d6a6b6c6d);
>   #endif
>   #undef test_legit
> +}
>   
> -	/* Test usage of check_nonzero_user(). */
> -	ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE);
> -	/* Test usage of copy_struct_from_user(). */
> -	ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE);
> -
> -	/*
> -	 * Invalid usage: none of these copies should succeed.
> -	 */
> +/*
> + * Invalid usage: none of these copies should succeed.
> + */
> +static void usercopy_test_invalid(struct kunit *test)
> +{
> +	struct usercopy_test_priv *priv = test->priv;
> +	char __user *usermem = priv->umem;
> +	char *bad_usermem = (char *)usermem;
> +	char *kmem = priv->kmem;
>   
>   	/* Prepare kernel memory with check values. */
>   	memset(kmem, 0x5a, PAGE_SIZE);
>   	memset(kmem + PAGE_SIZE, 0, PAGE_SIZE);
>   
>   	/* Reject kernel-to-kernel copies through copy_from_user(). */
> -	ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
> -				    PAGE_SIZE),
> +	KUNIT_EXPECT_NE_MSG(test, copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
> +						 PAGE_SIZE), 0,
>   		    "illegal all-kernel copy_from_user passed");
>   
>   	/* Destination half of buffer should have been zeroed. */
> -	ret |= test(memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE),
> +	KUNIT_EXPECT_EQ_MSG(test, memcmp(kmem + PAGE_SIZE, kmem, PAGE_SIZE), 0,
>   		    "zeroing failure for illegal all-kernel copy_from_user");
>   
>   #if 0
> @@ -273,29 +249,25 @@ static int __init test_user_copy_init(void)
>   	 * to be tested in LKDTM instead, since this test module does not
>   	 * expect to explode.
>   	 */
> -	ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem,
> -				    PAGE_SIZE),
> +	KUNIT_EXPECT_NE_MSG(test, copy_from_user(bad_usermem, (char __user *)kmem,
> +						 PAGE_SIZE), 0,
>   		    "illegal reversed copy_from_user passed");
>   #endif
> -	ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
> -				  PAGE_SIZE),
> +	KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
> +					       PAGE_SIZE), 0,
>   		    "illegal all-kernel copy_to_user passed");
> -	ret |= test(!copy_to_user((char __user *)kmem, bad_usermem,
> -				  PAGE_SIZE),
> +	KUNIT_EXPECT_NE_MSG(test, copy_to_user((char __user *)kmem, bad_usermem,
> +					       PAGE_SIZE), 0,
>   		    "illegal reversed copy_to_user passed");
>   
>   #define test_illegal(size, check)					    \
>   	do {								    \
> -		val_##size = (check);					    \
> -		ret |= test(!get_user(val_##size, (size __user *)kmem),	    \
> +		size val_##size = (check);					    \
> +		KUNIT_EXPECT_NE_MSG(test, get_user(val_##size, (size __user *)kmem), 0, \
>   		    "illegal get_user (" #size ") passed");		    \
> -		ret |= test(val_##size != (size)0,			    \
> +		KUNIT_EXPECT_EQ_MSG(test, val_##size, 0,		    \
>   		    "zeroing failure for illegal get_user (" #size ")");    \
> -		if (val_##size != (size)0) {				    \
> -			pr_info("0x%llx != 0\n",			    \
> -				(unsigned long long)val_##size);	    \
> -		}							    \
> -		ret |= test(!put_user(val_##size, (size __user *)kmem),	    \
> +		KUNIT_EXPECT_NE_MSG(test, put_user(val_##size, (size __user *)kmem), 0, \
>   		    "illegal put_user (" #size ") passed");		    \
>   	} while (0)
>   
> @@ -306,26 +278,46 @@ static int __init test_user_copy_init(void)
>   	test_illegal(u64, 0x5a5b5c5d6a6b6c6d);
>   #endif
>   #undef test_illegal
> +}
>   
> -	vm_munmap(user_addr, PAGE_SIZE * 2);
> -	kfree(kmem);
> +static int usercopy_test_init(struct kunit *test)
> +{
> +	struct usercopy_test_priv *priv;
> +	unsigned long user_addr;
>   
> -	if (ret == 0) {
> -		pr_info("tests passed.\n");
> -		return 0;
> -	}
> +	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;

Should the check be done with KUNIT_ASSERT_NOT_ERR_OR_NULL here as well, 
as it is done with priv->kmem?

> +	test->priv = priv;
> +	priv->size = PAGE_SIZE * 2;
>   
> -	return -EINVAL;
> -}
> +	priv->kmem = kunit_kmalloc(test, priv->size, GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->kmem);
>   
> -module_init(test_user_copy_init);
> +	user_addr = kunit_vm_mmap(test, NULL, 0, priv->size,
> +			    PROT_READ | PROT_WRITE | PROT_EXEC,
> +			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
> +	KUNIT_ASSERT_LT_MSG(test, user_addr, (unsigned long)TASK_SIZE,
> +		"Failed to allocate user memory");
> +	priv->umem = (char __user *)user_addr;
>   
> -static void __exit test_user_copy_exit(void)
> -{
> -	pr_info("unloaded.\n");
> +	return 0;
>   }
>   
> -module_exit(test_user_copy_exit);
> -
> +static struct kunit_case usercopy_test_cases[] = {
> +	KUNIT_CASE(usercopy_test_valid),
> +	KUNIT_CASE(usercopy_test_invalid),
> +	KUNIT_CASE(usercopy_test_check_nonzero_user),
> +	KUNIT_CASE(usercopy_test_copy_struct_from_user),
> +	{}
> +};
> +
> +static struct kunit_suite usercopy_test_suite = {
> +	.name = "usercopy",
> +	.init = usercopy_test_init,
> +	.test_cases = usercopy_test_cases,
> +};
> +
> +kunit_test_suites(&usercopy_test_suite);
>   MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
>   MODULE_LICENSE("GPL");

Other than that,

Tested-by: Ivan Orlov <ivan.orlov0322@gmail.com>
-- 
Kind regards,
Ivan Orlov