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From:   Andreas Schwab <schwab@linux-m68k.org>
To:     YueHaibing <yuehaibing@huawei.com>
Cc:     <davem@davemloft.net>, <ubraun@linux.ibm.com>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-s390@vger.kernel.org>
Subject: Re: [PATCH net-next] net/smc: cast sizeof to int for comparison
References: <20180915100036.20100-1-yuehaibing@huawei.com>
        <87zhwj6liz.fsf@igel.home>
        <b598de63-f026-c3ff-3380-8b1814f90b82@huawei.com>
Date:   Mon, 17 Sep 2018 10:42:02 +0200
In-Reply-To: <b598de63-f026-c3ff-3380-8b1814f90b82@huawei.com> (YueHaibing's
        message of "Mon, 17 Sep 2018 11:57:40 +0800")
Message-ID: <mvm8t40zfad.fsf@linux-m68k.org>
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On Sep 17 2018, YueHaibing <yuehaibing@huawei.com> wrote:

> On 2018/9/15 19:35, Andreas Schwab wrote:
>> On Sep 15 2018, YueHaibing <yuehaibing@huawei.com> wrote:
>> 
>>> Comparing an int to a size, which is unsigned, causes the int to become
>>> unsigned, giving the wrong result. kernel_sendmsg can return a negative
>>> error code.
>>>
>>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>>> ---
>>>  net/smc/smc_clc.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
>>> index 83aba9a..fd0f5ce 100644
>>> --- a/net/smc/smc_clc.c
>>> +++ b/net/smc/smc_clc.c
>>> @@ -446,7 +446,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
>>>  	vec[i++].iov_len = sizeof(trl);
>>>  	/* due to the few bytes needed for clc-handshake this cannot block */
>>>  	len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
>>> -	if (len < sizeof(pclc)) {
>>> +	if (len < (int)sizeof(pclc)) {
>>>  		if (len >= 0) {
>>>  			reason_code = -ENETUNREACH;
>>>  			smc->sk.sk_err = -reason_code;
>> 
>> It would perhaps be better to handle len < 0 first.
>
> That need refactor the err hangding, is worth doing it?

Just a few lines moving around, IFAICS.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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