Re: [PATCH bpf-next v2 2/2] bpf: Introduce bpf user log

[Leon Hwang <hffilwlqm@gmail.com>]

On 11/7/23 07:45, Alexei Starovoitov wrote:
> On Fri, Jul 7, 2023 at 9:08 PM Leon Hwang <hffilwlqm@gmail.com> wrote:
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index 34fa334938ba5..8a458cfcd91bd 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -1549,7 +1549,6 @@ union bpf_attr {
>>                 };
>>                 __u32           attach_type;    /* attach type */
>>                 __u32           flags;          /* extra flags */
>> -               struct bpf_generic_user_log log; /* user log */
>>                 union {
>>                         __u32           target_btf_id;  /* btf_id of target to attach to */
>>                         struct {
>> @@ -1585,6 +1584,9 @@ union bpf_attr {
>>                                 __s32           priority;
>>                                 __u32           flags;
>>                         } netfilter;
>> +                       struct {
>> +                               struct bpf_generic_user_log ulog; /* user log */
>> +                       } xdp;
> 
> 1.
> You cannot break api in patch 1 and fix it in patch 2.
> 
> 2.
> libbpf side is missing.
> 
> 3.
> selftest is missing.
> 
> 4.
> bpf_vlog_finalize() should be used and error propagated back through
> link_create.
> Same api must be used: log_level, log_size, log_buf, log_true_size.
> 
> But considering all that I agree with Daniel Xu that
> tracepoint would be better here.

Sorry for missing 2&3.

Tracepoint is considered. I'll change it from user log to a tracepoint.

I'll submit tracepoint patch with libbpf&selftest patches later.

Thanks,
Leon