From: Zhang Yunkai <[email protected]>
WARNING: Unsigned expression "queue" compared with zero.
Reported-by: Zeal Robot <[email protected]>
Signed-off-by: Zhang Yunkai <[email protected]>
---
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;
}
--
2.25.1
> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: 2021??7??15?? 15:46
> To: [email protected]
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; Zhang
> Yunkai <[email protected]>; Zeal Robot <[email protected]>
> Subject: [PATCH linux-next] net:stmmac: Fix the unsigned expression compared
> with zero
>
> From: Zhang Yunkai <[email protected]>
>
> WARNING: Unsigned expression "queue" compared with zero.
> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Zhang Yunkai <[email protected]>
> ---
> 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
On Thu, Jul 15, 2021 at 10:12:04AM +0000, Joakim Zhang wrote:
>
> > -----Original Message-----
> > From: [email protected] <[email protected]>
> > Sent: 2021年7月15日 15:46
> > To: [email protected]
> > Cc: [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; Zhang
> > Yunkai <[email protected]>; Zeal Robot <[email protected]>
> > Subject: [PATCH linux-next] net:stmmac: Fix the unsigned expression compared
> > with zero
> >
> > From: Zhang Yunkai <[email protected]>
> >
> > WARNING: Unsigned expression "queue" compared with zero.
> > Reported-by: Zeal Robot <[email protected]>
> > Signed-off-by: Zhang Yunkai <[email protected]>
> > ---
> > 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