Re: [PATCH bpf v3 4/5] selftests/bpf: Add test for key-less BTF hash map

[Jiayuan Chen <jiayuan.chen@linux.dev>]

在 8/31/26 7:48 PM, bot+bpf-ci@kernel.org 写道:
>> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_map_keyless.c b/tools/testing/selftests/bpf/prog_tests/btf_map_keyless.c
>> new file mode 100644
>> index 0000000000000..a7d037f57a7ef
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/prog_tests/btf_map_keyless.c
>> @@ -0,0 +1,82 @@
> [ ... ]
>
>> +	/*
>> +	 * Positive control: the same map with a real key type must be accepted,
>> +	 * so the -EINVAL below is about the key-less BTF and not some unrelated
>> +	 * rejection (e.g. an unknown map type).
>> +	 */
>> +	opts.btf_key_type_id = val_id;
>> +	map_fd = bpf_map_create(map_type, "keyed_map", 4, 4, 8, &opts);
>> +	if (!ASSERT_GE(map_fd, 0, "keyed create is accepted"))
>> +		return;
>> +	close(map_fd);
> A subsystem pattern flags this as potentially concerning: the positive
> control turns "this kernel does not implement the map type" into a hard test
> failure instead of a skip.
>
> BPF_MAP_TYPE_RHASH (used by the rhash subtest) is new; on any kernel that
> lacks it, map_create() rejects the unknown map type and this ASSERT_GE fails,
> reporting a red btf_map_keyless/rhash that has nothing to do with the
> behaviour under test.

Selftests run against the matching kernel, where the map type exists, so 
this doesn't happen.