[PATCH v4 03/11] test: unit test for u16_strlcat()

[Heinrich Schuchardt]

On 3/24/22 14:54, Masahisa Kojima wrote:
> Provide a unit test for function u16_strlcat().
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> No change since v2
>
> Newly created in v2
>
>   test/unicode_ut.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 45 insertions(+)
>
> diff --git a/test/unicode_ut.c b/test/unicode_ut.c
> index f2f63d5367..f79b0439bc 100644
> --- a/test/unicode_ut.c
> +++ b/test/unicode_ut.c
> @@ -758,6 +758,51 @@ static int unicode_test_efi_create_indexed_name(struct unit_test_state *uts)
>   UNICODE_TEST(unicode_test_efi_create_indexed_name);
>   #endif
>
> +static int unicode_test_u16_strlcat(struct unit_test_state *uts)
> +{
> +	u16 buf[11];

buf should be longer then the expected test result, e.g. buf[40].

> +	u16 dest[] = u"U-Boot";
> +	u16 src[] = u"test";

The letters in the test should be different to each other and should not
have zero bytes. You could use:

dest = {0x043b, 0x043e, 0x0434, 0x043a, 0x0430, 0} /* u"лодка" */
src = {0x6f5c, 0x8247, 0} /* u"潜艇" */

> +	u16 expected[] = u"U-Boottest";
> +	u16 null_src = u'\0';
> +	size_t ret;
> +

If you want to detect failures, you have to set the unused buffer bytes
to non-zero values except for the last two bytes which should be set to
zero.

> +	memcpy(buf, dest, sizeof(dest));
> +	ret = u16_strlcat(buf, src, sizeof(buf));
> +	ut_asserteq(20, ret);
> +	ut_assert(!unicode_test_u16_strcmp(buf, expected, 11));
> +
> +	/* dest is empty string */
> +	memset(buf, 0, sizeof(buf));
> +	ret = u16_strlcat(buf, src, sizeof(buf));
> +	ut_asserteq(8, ret);
> +	ut_assert(!unicode_test_u16_strcmp(buf, src, 11));
> +
> +	/* src is empty string */
> +	memset(buf, 0, sizeof(buf));
> +	memcpy(buf, dest, sizeof(dest));
> +	ret = u16_strlcat(buf, &null_src, sizeof(buf));
> +	ut_asserteq(12, ret);
> +	ut_assert(!unicode_test_u16_strcmp(buf, dest, 11));
> +
> +	/* size is smaller than dest size */
> +	memset(buf, 0, sizeof(buf));
> +	memcpy(buf, dest, sizeof(dest));
> +	ret = u16_strlcat(buf, src, 6);
> +	ut_asserteq(14, ret);
> +	ut_assert(!unicode_test_u16_strcmp(buf, dest, 11));
> +
> +	/* size is insufficient to append src string */
> +	memset(buf, 0, sizeof(buf));
> +	memcpy(buf, dest, sizeof(dest));
> +	ret = u16_strlcat(buf, src, 20);
> +	ut_asserteq(20, ret);
> +	ut_assert(!unicode_test_u16_strcmp(buf, u"U-Boottes", 11));

This test does not catch all corner cases. You never use an odd value
for size. E.g. size = 13 lead to a buffer overrun which you did not catch.

Please, enclose your tests in a loop for size from 0 to sizeof(buf) - 2
where sizeof(buf) is larger then any expected string size.

Test with dest and/or src being { 0 } too.

Best regards

Heinrich

> +
> +	return 0;
> +}
> +UNICODE_TEST(unicode_test_u16_strlcat);
> +
>   int do_ut_unicode(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
>   {
>   	struct unit_test *tests = UNIT_TEST_SUITE_START(unicode_test);