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From:   Menglong Dong <menglong8.dong@gmail.com>
Date:   Thu, 25 Aug 2022 10:29:25 +0800
Message-ID: <CADxym3bC8=cLp4_n9OTQpV_Hw=XuTZySr96RrahQXfAKt0q2=g@mail.gmail.com>
Subject: Re: [PATCH net-next v4 2/3] net: skb: use auto-generation to convert
 skb drop reason to string
To:     Jakub Kicinski <kuba@kernel.org>,
        Eric Dumazet <edumazet@google.com>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        David Miller <davem@davemloft.net>,
        Paolo Abeni <pabeni@redhat.com>,
        Neil Horman <nhorman@tuxdriver.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Menglong Dong <imagedong@tencent.com>,
        David Ahern <dsahern@kernel.org>,
        Talal Ahmad <talalahmad@google.com>,
        Kees Cook <keescook@chromium.org>,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
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On Thu, Aug 25, 2022 at 9:10 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 24 Aug 2022 17:45:15 -0700 Eric Dumazet wrote:
> > After this patch, I no longer have strings added after the reason: tag
>
> Hm, using a kernel address (drop_reasons) as an argument to TP_printk()
> definitely does not look right, but how to tickle whatever magic
> __print_symbolic was providing I do not know :S
>
>         TP_printk("skbaddr=%p protocol=%u location=%p reason: %s",
>                   __entry->skbaddr, __entry->protocol, __entry->location,
> -                 __print_symbolic(__entry->reason,
> -                                  TRACE_SKB_DROP_REASON))
> +                 drop_reasons[__entry->reason])

it seems that TP_printk is not as simple as I thought.......

Sorry for the problem I brought, I'm looking for a solution.

Thanks!
Menglong Dong