Re: [PATCH bpf-next v10 3/8] bpf: Refactor reporting log_true_size for prog_load

[Leon Hwang <leon.hwang@linux.dev>]

On 4/3/26 13:58, Alexei Starovoitov wrote:
> On Tue, Mar 3, 2026 at 9:47 PM Leon Hwang <leon.hwang@linux.dev> wrote:
>>
>> On 4/3/26 00:32, Alexei Starovoitov wrote:
>>> On Wed, Feb 11, 2026 at 7:13 AM Leon Hwang <leon.hwang@linux.dev> wrote:
>>>>
>>
>> [...]
>>
>>>> @@ -6241,7 +6244,11 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size,
>>>>                 err = map_freeze(&attr);
>>>>                 break;
>>>>         case BPF_PROG_LOAD:
>>>> -               err = bpf_prog_load(&attr, uattr, size);
>>>> +               if (from_user && size >= offsetofend(union bpf_attr, log_true_size))
>>>> +                       log_true_size = uattr.user + offsetof(union bpf_attr, log_true_size);
>>>
>>> So you added 'from_user' gating because
>>> you replaced copy_to_bpfptr_offset() with copy_to_user()?
>>> This is a drastic change in behavior and you don't even talk about
>>> it in the commit log.
>>> You said "refactor". This is not a refactoring!
>>>
>>> This is v10. The common_attr feature is useful, but
>>> you really need to think harder about what your patches
>>> are doing.
>>>
>>
>> Refactoring should not introduce any functional changes. If a functional
>> change is involved, it should be factored out of the refactoring commit
>> into a separate commit with an explanation in the commit log.
>>
>> I'll add this to my self-review checklist.
>>
>> The intention of 'from_user' was to replace copy_to_bpfptr_offset() with
>> copy_to_user(), since the log is always copied to the user-space buffer
>> when the log level is not BPF_LOG_KERNEL in
>> kernel/bpf/log.c::bpf_verifier_vlog().
>>
>> The 'from_user' gating will be dropped in v12 to keep this patch as pure
>> refactoring.
> 
> You were told multiple times to avoid copy pasting AI into your emails.
> Sorry, but this crosses the line for me.
> Your patches will be ignored for 2 weeks.

Oops. The above reply was written by my hand. Possibly, the reply
carried LLM smell because I learnt LLM tongue recently.

As you said, I won't send patches for 2 weeks. :-(

Thanks,
Leon