From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Giuseppe Cavallaro <peppe.cavallaro@st.com>,
Alexandre Torgue <alexandre.torgue@st.com>,
Jose Abreu <joabreu@synopsys.com>,
"David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] net: stmmac_tc: use 64-bit arithmetic instead of 32-bit
Date: Mon, 2 Jul 2018 07:09:32 -0500 [thread overview]
Message-ID: <20180702120932.GA13079@embeddedor.com> (raw)
Add suffix UL to constant 1024 in order to give the compiler complete
information about the proper arithmetic to use. Notice that this
constant is used in a context that expects an expression of type
u64 (64 bits, unsigned) and following expressions are currently
being evaluated using 32-bit arithmetic:
qopt->idleslope * 1024 * ptr
qopt->hicredit * 1024 * 8
qopt->locredit * 1024 * 8
Addresses-Coverity-ID: 1470246 ("Unintentional integer overflow")
Addresses-Coverity-ID: 1470248 ("Unintentional integer overflow")
Addresses-Coverity-ID: 1470249 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 0b0fca0..8fedc28 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -321,7 +321,7 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
speed_div = (priv->speed == SPEED_100) ? 100000 : 1000000;
/* Final adjustments for HW */
- value = qopt->idleslope * 1024 * ptr;
+ value = qopt->idleslope * 1024UL * ptr;
do_div(value, speed_div);
priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
@@ -329,10 +329,10 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
do_div(value, speed_div);
priv->plat->tx_queues_cfg[queue].send_slope = value & GENMASK(31, 0);
- value = qopt->hicredit * 1024 * 8;
+ value = qopt->hicredit * 1024UL * 8;
priv->plat->tx_queues_cfg[queue].high_credit = value & GENMASK(31, 0);
- value = qopt->locredit * 1024 * 8;
+ value = qopt->locredit * 1024UL * 8;
priv->plat->tx_queues_cfg[queue].low_credit = value & GENMASK(31, 0);
ret = stmmac_config_cbs(priv, priv->hw,
--
2.7.4
next reply other threads:[~2018-07-02 12:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-02 12:09 Gustavo A. R. Silva [this message]
2018-07-02 15:19 ` [PATCH] net: stmmac_tc: use 64-bit arithmetic instead of 32-bit Jose Abreu
2018-07-03 14:21 ` David Miller
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