From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Andreas Schwab Subject: Re: [PATCH net-next] net/smc: cast sizeof to int for comparison References: <20180915100036.20100-1-yuehaibing@huawei.com> Date: Sat, 15 Sep 2018 13:35:32 +0200 In-Reply-To: <20180915100036.20100-1-yuehaibing@huawei.com> (YueHaibing's message of "Sat, 15 Sep 2018 18:00:36 +0800") Message-ID: <87zhwj6liz.fsf@igel.home> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: YueHaibing Cc: davem@davemloft.net, ubraun@linux.ibm.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org List-ID: On Sep 15 2018, YueHaibing 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 > --- > 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. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."