From: Joakim Zhang <qiangqing.zhang@nxp.com>
To: "menglong8.dong@gmail.com" <menglong8.dong@gmail.com>,
"davem@davemloft.net" <davem@davemloft.net>
Cc: "peppe.cavallaro@st.com" <peppe.cavallaro@st.com>,
"alexandre.torgue@foss.st.com" <alexandre.torgue@foss.st.com>,
"joabreu@synopsys.com" <joabreu@synopsys.com>,
"kuba@kernel.org" <kuba@kernel.org>,
"mcoquelin.stm32@gmail.com" <mcoquelin.stm32@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-stm32@st-md-mailman.stormreply.com"
<linux-stm32@st-md-mailman.stormreply.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Zhang Yunkai <zhang.yunkai@zte.com.cn>,
Zeal Robot <zealci@zte.com.cn>
Subject: RE: [PATCH linux-next] net:stmmac: Fix the unsigned expression compared with zero
Date: Thu, 15 Jul 2021 10:12:04 +0000 [thread overview]
Message-ID: <DB8PR04MB679513459A42E7A7982CE91EE6129@DB8PR04MB6795.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20210715074539.226600-1-zhang.yunkai@zte.com.cn>
> -----Original Message-----
> From: menglong8.dong@gmail.com <menglong8.dong@gmail.com>
> Sent: 2021年7月15日 15:46
> To: davem@davemloft.net
> Cc: peppe.cavallaro@st.com; alexandre.torgue@foss.st.com;
> joabreu@synopsys.com; kuba@kernel.org; mcoquelin.stm32@gmail.com;
> netdev@vger.kernel.org; linux-stm32@st-md-mailman.stormreply.com;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Zhang
> Yunkai <zhang.yunkai@zte.com.cn>; Zeal Robot <zealci@zte.com.cn>
> Subject: [PATCH linux-next] net:stmmac: Fix the unsigned expression compared
> with zero
>
> From: Zhang Yunkai <zhang.yunkai@zte.com.cn>
>
> WARNING: Unsigned expression "queue" compared with zero.
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Zhang Yunkai <zhang.yunkai@zte.com.cn>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 7b8404a21544..a4cf2c640531 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1699,7 +1699,7 @@ static int init_dma_rx_desc_rings(struct net_device
> *dev, gfp_t flags)
> return 0;
>
> err_init_rx_buffers:
> - while (queue >= 0) {
> + do {
> struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
>
> if (rx_q->xsk_pool)
> @@ -1710,11 +1710,7 @@ static int init_dma_rx_desc_rings(struct
> net_device *dev, gfp_t flags)
> rx_q->buf_alloc_num = 0;
> rx_q->xsk_pool = NULL;
>
> - if (queue == 0)
> - break;
> -
> - queue--;
> - }
> + } while (queue--);
>
> return ret;
> }
This is a real Coverity issue since queue variable is defined as u32, but there is no breakage from logic, it will break while loop when queue equal 0, and queue[0] actually need be handled.
After your code change, queue[0] will not be handled, right? It will break the logic. If you want to fix the this issue, I think the easiest way is to define queue variable to int.
Best Regards,
Joakim Zhang
> --
> 2.25.1
next prev parent reply other threads:[~2021-07-15 10:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-15 7:45 [PATCH linux-next] net:stmmac: Fix the unsigned expression compared with zero menglong8.dong
2021-07-15 10:12 ` Joakim Zhang [this message]
2021-07-16 0:54 ` Wong Vee Khee
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