Re: [PATCH v7 1/2] lib: checksum: Fix type casting in checksum kunits

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Feb 12, 2024 at 12:33:04PM -0800, Charlie Jenkins wrote:
> The checksum functions use the types __wsum and __sum16. These need to
> be explicitly casted to, because will cause sparse errors otherwise.
> 
> Fixes: 6f4c45cbcb00 ("kunit: Add tests for csum_ipv6_magic and ip_fast_csum")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202401200106.PMTn6g56-lkp@intel.com/
> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  lib/checksum_kunit.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/checksum_kunit.c b/lib/checksum_kunit.c
> index 225bb7701460..776ad3d6d5a1 100644
> --- a/lib/checksum_kunit.c
> +++ b/lib/checksum_kunit.c
> @@ -215,7 +215,7 @@ static const u32 init_sums_no_overflow[] = {
>  	0xffff0000, 0xfffffffb,
>  };
>  
> -static const __sum16 expected_csum_ipv6_magic[] = {
> +static const u16 expected_csum_ipv6_magic[] = {
>  	0x18d4, 0x3085, 0x2e4b, 0xd9f4, 0xbdc8, 0x78f,	0x1034, 0x8422, 0x6fc0,
>  	0xd2f6, 0xbeb5, 0x9d3,	0x7e2a, 0x312e, 0x778e, 0xc1bb, 0x7cf2, 0x9d1e,
>  	0xca21, 0xf3ff, 0x7569, 0xb02e, 0xca86, 0x7e76, 0x4539, 0x45e3, 0xf28d,
> @@ -241,7 +241,7 @@ static const __sum16 expected_csum_ipv6_magic[] = {
>  	0x3845, 0x1014
>  };
>  
> -static const __sum16 expected_fast_csum[] = {
> +static const u16 expected_fast_csum[] = {
>  	0xda83, 0x45da, 0x4f46, 0x4e4f, 0x34e,	0xe902, 0xa5e9, 0x87a5, 0x7187,
>  	0x5671, 0xf556, 0x6df5, 0x816d, 0x8f81, 0xbb8f, 0xfbba, 0x5afb, 0xbe5a,
>  	0xedbe, 0xabee, 0x6aac, 0xe6b,	0xea0d, 0x67ea, 0x7e68, 0x8a7e, 0x6f8a,
> @@ -582,7 +582,7 @@ static void test_ip_fast_csum(struct kunit *test)
>  	for (int len = IPv4_MIN_WORDS; len < IPv4_MAX_WORDS; len++) {
>  		for (int index = 0; index < NUM_IP_FAST_CSUM_TESTS; index++) {
>  			csum_result = ip_fast_csum(random_buf + index, len);
> -			expected =
> +			expected = (__force __sum16)
>  				expected_fast_csum[(len - IPv4_MIN_WORDS) *
>  						   NUM_IP_FAST_CSUM_TESTS +
>  						   index];
> @@ -614,8 +614,9 @@ static void test_csum_ipv6_magic(struct kunit *test)
>  		len = *(unsigned int *)(random_buf + i + len_offset);
>  		proto = *(random_buf + i + proto_offset);
>  		csum = *(unsigned int *)(random_buf + i + csum_offset);
> -		CHECK_EQ(expected_csum_ipv6_magic[i],
> -			 csum_ipv6_magic(saddr, daddr, len, proto, csum));
> +		CHECK_EQ((__force __sum16)expected_csum_ipv6_magic[i],
> +			 csum_ipv6_magic(saddr, daddr, len, proto,
> +					 (__force __wsum)csum));
>  	}
>  #endif /* !CONFIG_NET */
>  }
> 
> -- 
> 2.43.0
>