Re: [PATCH bpf-next v11 4/8] bpf: Introduce the bpf_list_del kfunc.

[Kaitao Cheng]

在 2026/5/21 12:08, bot+bpf-ci@xxxxxxxxxx 写道:
>> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
>> index 59855b434f0b..804c201c28f3 100644
>> --- a/kernel/bpf/helpers.c
>> +++ b/kernel/bpf/helpers.c
> 
> [ ... ]
> 
>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
>> index f3cf8d85bea0..35eebb5e7769 100644
>> --- a/kernel/bpf/verifier.c
>> +++ b/kernel/bpf/verifier.c
> 
> [ ... ]
> 
>> @@ -11671,7 +11674,8 @@ static bool check_kfunc_is_graph_node_api(struct bpf_verifier_env *env,
>>
>>  	switch (node_field_type) {
>>  	case BPF_LIST_NODE:
>> -		ret = is_bpf_list_push_kfunc(kfunc_btf_id);
>> +		ret = is_bpf_list_push_kfunc(kfunc_btf_id) ||
>> +		      kfunc_btf_id == special_kfunc_list[KF_bpf_list_del];
> 
> This isn't a bug, but Eduard Zingerman suggested in v10 adding a
> is_bpf_list_del_kfunc() helper for consistency with the existing code style
> (similar to is_bpf_list_push_kfunc()). This would maintain the pattern used
> throughout the codebase for checking kfunc types.
> 
> Reference: https://lore.kernel.org/bpf/ca14a6fd8a1f3ce1e64c70b6d9ea2baf8df913ae.camel@xxxxxxxxx/

The reason for using is_bpf_list_push_kfunc() is that it groups multiple parallel
"kfunc_btf_id == special_kfunc_list[*]" checks into one helper, making the code
easier to reuse. If we added is_bpf_list_del_kfunc() here, it would only wrap a
single KF_bpf_list_del check, which is unnecessary. Also, more helpers such as
is_bpf_list_first/last may be added later, and overusing is_bpf_list_* helpers
would make the code more redundant.

> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
> 
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/26204125015

-- 
Thanks
Kaitao Cheng