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net: stmmac_tc: use 64-bit arithmetic instead of 32-bit
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Mon, 2 Jul 2018 12:09:32 +0000 (07:09 -0500)
committerDavid S. Miller <davem@davemloft.net>
Tue, 3 Jul 2018 14:21:07 +0000 (23:21 +0900)
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>
Acked-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c

index 0b0fca0..8fedc28 100644 (file)
@@ -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,