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Message-ID: <115c6eac-ab28-7220-e1e4-5747bf641bbe@gmail.com>
Date:   Tue, 11 Jul 2023 10:55:38 +0800
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Subject: Re: [PATCH bpf-next v2 2/2] bpf: Introduce bpf user log
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To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        John Fastabend <john.fastabend@gmail.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Yizhou Tang <tangyeechou@gmail.com>, kernel-patches-bot@fb.com,
        bpf <bpf@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Network Development <netdev@vger.kernel.org>
References: <20230708040750.72570-1-hffilwlqm@gmail.com>
 <20230708040750.72570-3-hffilwlqm@gmail.com>
 <CAADnVQK5RLqVhc9AxaCSuQxFRDAb8wohmUDNrYEViXLf5mEMNQ@mail.gmail.com>
From:   Leon Hwang <hffilwlqm@gmail.com>
In-Reply-To: <CAADnVQK5RLqVhc9AxaCSuQxFRDAb8wohmUDNrYEViXLf5mEMNQ@mail.gmail.com>
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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