Re: [PATCH v2 bpf-next 5/6] selftest/bpf: Add BTF_KIND_FLOAT tests

[Yonghong Song <yhs@fb.com>]

On 2/18/21 6:25 PM, Ilya Leoshkevich wrote:
> Test the good variants as well as the potential malformed ones.
> 
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   tools/testing/selftests/bpf/btf_helpers.c    |   4 +
>   tools/testing/selftests/bpf/prog_tests/btf.c | 122 +++++++++++++++++++
>   tools/testing/selftests/bpf/test_btf.h       |   3 +
>   3 files changed, 129 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c
> index 48f90490f922..b692e6ead9b5 100644
> --- a/tools/testing/selftests/bpf/btf_helpers.c
> +++ b/tools/testing/selftests/bpf/btf_helpers.c
> @@ -23,6 +23,7 @@ static const char * const btf_kind_str_mapping[] = {
>   	[BTF_KIND_FUNC_PROTO]	= "FUNC_PROTO",
>   	[BTF_KIND_VAR]		= "VAR",
>   	[BTF_KIND_DATASEC]	= "DATASEC",
> +	[BTF_KIND_FLOAT]	= "FLOAT",
>   };
>   
>   static const char *btf_kind_str(__u16 kind)
> @@ -173,6 +174,9 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
>   		}
>   		break;
>   	}
> +	case BTF_KIND_FLOAT:
> +		fprintf(out, " size=%u", t->size);
> +		break;
>   	default:
>   		break;
>   	}
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
> index 6a7ee7420701..4be14d853cc3 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf.c
> @@ -3531,6 +3531,127 @@ static struct btf_raw_test raw_tests[] = {
>   	.max_entries = 1,
>   },
>   
> +{
> +	.descr = "float test #1, well-formed",
> +	.raw_types = {
> +		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
> +		BTF_TYPE_FLOAT_ENC(1, 2),			/* [2] */
> +		BTF_TYPE_FLOAT_ENC(10, 4),			/* [3] */
> +		BTF_TYPE_FLOAT_ENC(16, 8),			/* [4] */
> +		BTF_TYPE_FLOAT_ENC(23, 16),			/* [5] */
> +		BTF_STRUCT_ENC(35, 4, 32),			/* [6] */

The float and struct names can also use NAME_TBD to avoid potential
miss counting, I think. This also make it consistent with using NAME_TBD 
below.

> +		BTF_MEMBER_ENC(NAME_TBD, 2, 0),
> +		BTF_MEMBER_ENC(NAME_TBD, 3, 32),
> +		BTF_MEMBER_ENC(NAME_TBD, 4, 64),
> +		BTF_MEMBER_ENC(NAME_TBD, 5, 128),
> +		BTF_END_RAW,
> +	},
> +	BTF_STR_SEC("\0_Float16\0float\0double\0long_double\0floats"),
> +	.map_type = BPF_MAP_TYPE_ARRAY,
> +	.map_name = "float_type_check_btf",
> +	.key_size = sizeof(int),
> +	.value_size = 32,
> +	.key_type_id = 1,
> +	.value_type_id = 6,
> +	.max_entries = 1,
> +},
> +{
[...]