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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
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 <5B9783ED.4080908@huawei.com>
 <e1b9c36c-5459-a68e-e6fd-cca038e31d5f@cogentembedded.com>
 <5B97889F.3020303@huawei.com>
From:   Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Message-ID: <6a9ff302-c86c-cd9e-7432-2de38d148678@cogentembedded.com>
Date:   Tue, 11 Sep 2018 12:33:00 +0300
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On 9/11/2018 12:19 PM, 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?
>>
>   I know that the patch should be BUG_ON instead of BUG. This is my mistake.  I just want to know that it is worthing to do so.

    Yes, probably.

>   Thanks,
>   zhong jiang
[...]

MBR, Sergei