| Message ID | 20210715074539.226600-1-zhang.yunkai@zte.com.cn |
|---|---|
| State | New |
| Headers | show |
| Series | [linux-next] net:stmmac: Fix the unsigned expression compared with zero | expand |
On Thu, Jul 15, 2021 at 10:12:04AM +0000, Joakim Zhang wrote: > > > -----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 > The function '__init_dma_rx_desc_rings' is expecting 'queue' to be u32 type. I would suggest the following:- @@ -1686,6 +1686,7 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags) struct stmmac_priv *priv = netdev_priv(dev); u32 rx_count = priv->plat->rx_queues_to_use; u32 queue; + u32 i; int ret; /* RX INITIALIZATION */ @@ -1701,21 +1702,16 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags) return 0; err_init_rx_buffers: - while (queue >= 0) { - struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue]; + for (i = 0; i <= queue; i++) { + struct stmmac_rx_queue *rx_q = &priv->rx_queue[i]; if (rx_q->xsk_pool) - dma_free_rx_xskbufs(priv, queue); + dma_free_rx_xskbufs(priv, i); else - dma_free_rx_skbufs(priv, queue); + dma_free_rx_skbufs(priv, i); rx_q->buf_alloc_num = 0; rx_q->xsk_pool = NULL; - - if (queue == 0) - break; - - queue--; } Regards, VK
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; }