[PATCH] net:fec: fixed unaligned access and stack corruption

[Enrico Scholz]

on 64 bit architectures, the 'enum fec_type' might not be aligned and
large enough to hold a pointer.  When running barebox without MMU,
this will crash like

| i.MX8MM unique ID: dab4b7491a2c4209
| DABT (current EL) exception (ESR 0x96000061) at 0x00000000fffefeb4
| elr: 00000000ffe14c28 lr : 00000000ffe196e0
| x0 : 0000000000000002 x1 : 00000000fffefeb4
| x2 : 00000000ffe91370 x3 : 00000000bfe1b6e8
| x4 : 0000000000000000 x5 : 0000000011000000
| ...
| Call trace:
| [<ffe14c28>] (dev_get_drvdata+0xc/0x30) from [<ffe1446c>] (device_probe+0x54/0xd0)
| [<ffe1446c>] (device_probe+0x54/0xd0) from [<ffe14530>] (match+0x48/0x58)
| [<ffe14530>] (match+0x48/0x58) from [<ffe14a64>] (register_driver+0xc0/0xd0)
| [<ffe14a64>] (register_driver+0xc0/0xd0) from [<ffe01738>] (start_barebox+0x64/0x90)

Signed-off-by: Enrico Scholz <enrico.scholz at sigma-chemnitz.de>
---
 drivers/net/fec_imx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/fec_imx.c b/drivers/net/fec_imx.c
index 772f930f0d08..30ee7841faba 100644
--- a/drivers/net/fec_imx.c
+++ b/drivers/net/fec_imx.c
@@ -739,14 +739,17 @@ static int fec_probe(struct device_d *dev)
 	void *base;
 	int ret;
 	enum fec_type type;
+	void const *type_v;
 	int phy_reset;
 	u32 msec = 1, phy_post_delay = 0;
 	u32 reg;
 
-	ret = dev_get_drvdata(dev, (const void **)&type);
+	ret = dev_get_drvdata(dev, &type_v);
 	if (ret)
 		return ret;
 
+	type = (uintptr_t)(type_v);
+
 	fec = xzalloc(sizeof(*fec));
 	fec->type = type;
 	fec->dev = dev;
-- 
2.25.4