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References: <20220610034204.67901-1-imagedong@tencent.com> <20220610034204.67901-6-imagedong@tencent.com>
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From:   Eric Dumazet <edumazet@google.com>
Date:   Fri, 10 Jun 2022 01:56:25 -0700
Message-ID: <CANn89i+NV1DgxaQbqPu2o0Du-94gDkM8DUrX_DK7=AGqvvPKdg@mail.gmail.com>
Subject: Re: [PATCH net-next v3 5/9] net: tcp: make tcp_rcv_state_process()
 return drop reason
To:     Menglong Dong <menglong8.dong@gmail.com>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>,
        David Miller <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Menglong Dong <imagedong@tencent.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Talal Ahmad <talalahmad@google.com>,
        Kees Cook <keescook@chromium.org>,
        Dongli Zhang <dongli.zhang@oracle.com>,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        Jiang Biao <benbjiang@tencent.com>,
        Hao Peng <flyingpeng@tencent.com>
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On Thu, Jun 9, 2022 at 8:45 PM <menglong8.dong@gmail.com> wrote:
>
> From: Menglong Dong <imagedong@tencent.com>
>
> For now, the return value of tcp_rcv_state_process() is treated as bool.
> Therefore, we can make it return the reasons of the skb drops.
>
> Meanwhile, the return value of tcp_child_process() comes from
> tcp_rcv_state_process(), make it drop reasons by the way.
>
> The new drop reason SKB_DROP_REASON_TCP_LINGER is added for skb dropping
> out of TCP linger.
>
> Reviewed-by: Jiang Biao <benbjiang@tencent.com>
> Reviewed-by: Hao Peng <flyingpeng@tencent.com>
> Signed-off-by: Menglong Dong <imagedong@tencent.com>
> v3:
> - instead SKB_DROP_REASON_TCP_ABORTONDATA with SKB_DROP_REASON_TCP_LINGER
> ---
>  include/net/dropreason.h |  6 ++++++
>  include/net/tcp.h        |  8 +++++---
>  net/ipv4/tcp_input.c     | 36 ++++++++++++++++++++----------------
>  net/ipv4/tcp_ipv4.c      | 20 +++++++++++++-------
>  net/ipv4/tcp_minisocks.c | 11 ++++++-----
>  net/ipv6/tcp_ipv6.c      | 19 ++++++++++++-------
>  6 files changed, 62 insertions(+), 38 deletions(-)
>

I am sorry, this patch is too invasive, and will make future bug fix
backports a real nightmare.