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Subject: Re: [PATCH] net: ipv4: Use BUG_ON directly instead of a if condition
 followed by BUG
To:     zhong jiang <zhongjiang@huawei.com>
Cc:     davem@davemloft.net, edumazet@google.com, kuznet@ms2.inr.ac.ru,
        yoshfuji@linux-ipv6.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1536590282-23899-1-git-send-email-zhongjiang@huawei.com>
 <a000b5a4-2907-70f9-70ed-7e1c6a797876@cogentembedded.com>
 <5B9783ED.4080908@huawei.com>
From:   Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Message-ID: <e1b9c36c-5459-a68e-e6fd-cca038e31d5f@cogentembedded.com>
Date:   Tue, 11 Sep 2018 12:11:45 +0300
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On 9/11/2018 11:59 AM, zhong jiang wrote:

>>> The if condition can be removed if we use BUG_ON directly.
>>> The issule is detected with the help of Coccinelle.
>>
>>    Issue?
>>
>>>
>>> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
>>> ---
>>>    net/ipv4/tcp_input.c | 8 ++++----
>>>    1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
>>> index 62508a2..893bde3 100644
>>> --- a/net/ipv4/tcp_input.c
>>> +++ b/net/ipv4/tcp_input.c
>>> @@ -4934,8 +4934,8 @@ void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb)
>>>                BUG_ON(offset < 0);
>>>                if (size > 0) {
>>>                    size = min(copy, size);
>>> -                if (skb_copy_bits(skb, offset, skb_put(nskb, size), size))
>>> -                    BUG();
>>> +                BUG(skb_copy_bits(skb, offset,
>>
>>     You said BUG_ON()?
>   Yep. Do you think that it is worthing to do

    I think BUG() doesn't take parameters, BUG_ON() does. Have you tried to 
build the kernel with your patch at all?

>   Thanks,
> zhong jiang
[...]

MBR, Sergei