From 3d33405ecdd7f3778b8310978dfb5c5df3bf1db7 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 16 Mar 2022 11:37:44 +0300
Subject: [PATCH 22/26] net: stmmac: clean up impossible condition
Git-commit: 58e06d05d43a9e37e121edabaada00a9d844444c
Patch-mainline: v5.18-rc1
References: git-fixes
This code works but it has a static checker warning:
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1687 init_dma_rx_desc_rings()
warn: always true condition '(queue >= 0) => (0-u32max >= 0)'
Obviously, it makes no sense to check if an unsigned int is >= 0. What
prevents this code from being a forever loop is that later there is a
separate check for if (queue == 0).
The "queue" variable is less than MTL_MAX_RX_QUEUES (8) so it can easily
fit in an int type. Any larger value for "queue" would lead to an array
overflow when we assign "rx_q = &priv->rx_queue[queue]".
Fixes: de0b90e52a11 ("net: stmmac: rearrange RX and TX desc init into per-queue basis")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220316083744.GB30941@kili
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index bac63a2f2218..5dd20da48fdf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1726,7 +1726,7 @@ 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;
+ int queue;
int ret;
/* RX INITIALIZATION */
@@ -1753,9 +1753,6 @@ 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--;
}
--
2.16.4