[U-Boot] [PATCH 6/8] net: ravb: Fix "left shift in type int" undefined behavior

Eugeniu Rosca roscaeugeniu at gmail.com
Mon Aug 20 00:00:30 UTC 2018


Running "tftp" on R-Car H3 Salvator-X with CONFIG_UBSAN=y results in:

=> tftp
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:237:28
left shift of 10 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:258:44
left shift of 9 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:263:46
left shift of 9 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:283:31
left shift of 9 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:288:49
left shift of 9 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:293:46
left shift of 9 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:345:2
left shift of 222 by 24 places cannot be represented in type 'int'
=====================================================================

Pinging the host results in:

=> ping 192.168.2.11
Using ethernet at e6800000 device
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:161:21
left shift of 15 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:182:25
left shift of 15 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:182:47
left shift of 12 by 28 places cannot be represented in type 'int'
=====================================================================
=====================================================================
UBSAN: Undefined behaviour in drivers/net/ravb.c:205:20
left shift of 12 by 28 places cannot be represented in type 'int'
=====================================================================
host 192.168.2.11 is alive

There are two issues behind:
 - calculating RAVB_DESC_DT_* bitfields
 - assembling MAC address from its char components

Fix both.

Fixes: 8ae51b6f324e ("net: ravb: Add Renesas Ethernet RAVB driver")
Signed-off-by: Eugeniu Rosca <erosca at de.adit-jv.com>
---
 drivers/net/ravb.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ravb.c b/drivers/net/ravb.c
index 749562db960e..5baff198889b 100644
--- a/drivers/net/ravb.c
+++ b/drivers/net/ravb.c
@@ -73,12 +73,12 @@
 #define RAVB_RX_QUEUE_OFFSET		4
 
 #define RAVB_DESC_DT(n)			((n) << 28)
-#define RAVB_DESC_DT_FSINGLE		RAVB_DESC_DT(0x7)
-#define RAVB_DESC_DT_LINKFIX		RAVB_DESC_DT(0x9)
-#define RAVB_DESC_DT_EOS		RAVB_DESC_DT(0xa)
-#define RAVB_DESC_DT_FEMPTY		RAVB_DESC_DT(0xc)
-#define RAVB_DESC_DT_EEMPTY		RAVB_DESC_DT(0x3)
-#define RAVB_DESC_DT_MASK		RAVB_DESC_DT(0xf)
+#define RAVB_DESC_DT_FSINGLE		RAVB_DESC_DT(0x7UL)
+#define RAVB_DESC_DT_LINKFIX		RAVB_DESC_DT(0x9UL)
+#define RAVB_DESC_DT_EOS		RAVB_DESC_DT(0xaUL)
+#define RAVB_DESC_DT_FEMPTY		RAVB_DESC_DT(0xcUL)
+#define RAVB_DESC_DT_EEMPTY		RAVB_DESC_DT(0x3UL)
+#define RAVB_DESC_DT_MASK		RAVB_DESC_DT(0xfUL)
 
 #define RAVB_DESC_DS(n)			(((n) & 0xfff) << 0)
 #define RAVB_DESC_DS_MASK		0xfff
@@ -342,8 +342,8 @@ static int ravb_write_hwaddr(struct udevice *dev)
 	struct eth_pdata *pdata = dev_get_platdata(dev);
 	unsigned char *mac = pdata->enetaddr;
 
-	writel((mac[0] << 24) | (mac[1] << 16) | (mac[2] << 8) | mac[3],
-	       eth->iobase + RAVB_REG_MAHR);
+	writel(((u32)mac[0] << 24) | ((u32)mac[1] << 16) | ((u32)mac[2] << 8) |
+	       mac[3], eth->iobase + RAVB_REG_MAHR);
 
 	writel((mac[4] << 8) | mac[5], eth->iobase + RAVB_REG_MALR);
 
-- 
2.18.0



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