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Message-ID: <b04eb1f8-b36a-9fce-5ae5-d4c770c36139@gmail.com>
Date:   Tue, 1 Aug 2023 11:47:58 +0800
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Subject: Re: [PATCH bpf-next v4 1/2] bpf, xdp: Add tracepoint to xdp attaching
 failure
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To:     Jakub Kicinski <kuba@kernel.org>
Cc:     ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com,
        andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
        yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, davem@davemloft.net,
        edumazet@google.com, pabeni@redhat.com, hawk@kernel.org,
        rostedt@goodmis.org, mhiramat@kernel.org, mykolal@fb.com,
        shuah@kernel.org, tangyeechou@gmail.com, kernel-patches-bot@fb.com,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org
References: <20230730114951.74067-1-hffilwlqm@gmail.com>
 <20230730114951.74067-2-hffilwlqm@gmail.com>
 <20230731194336.5b4bd065@kernel.org>
From:   Leon Hwang <hffilwlqm@gmail.com>
In-Reply-To: <20230731194336.5b4bd065@kernel.org>
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On 1/8/23 10:43, Jakub Kicinski wrote:
> On Sun, 30 Jul 2023 19:49:50 +0800 Leon Hwang wrote:
>> @@ -9472,6 +9473,7 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
>>  	struct bpf_link_primer link_primer;
>>  	struct bpf_xdp_link *link;
>>  	struct net_device *dev;
>> +	struct netlink_ext_ack extack;
> 
> This is not initialized. Also, while fixing that, move it up 
> to maintain the line order by decreasing line length.
> 

Thank you for your reviewing.

I'll fix it by initializing extack and moving the line to its appropriate position.

Thanks,
Leon

>>  	int err, fd;
>>  
>>  	rtnl_lock();
>> @@ -9497,12 +9499,13 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
>>  		goto unlock;
>>  	}
>>  
>> -	err = dev_xdp_attach_link(dev, NULL, link);
>> +	err = dev_xdp_attach_link(dev, &extack, link);
>>  	rtnl_unlock();
>>  
>>  	if (err) {
>>  		link->dev = NULL;
>>  		bpf_link_cleanup(&link_primer);
>> +		trace_bpf_xdp_link_attach_failed(extack._msg);