net: mcf: check receive buffer size register value

ColdFire Fast Ethernet Controller uses a receive buffer size
register(EMRBR) to hold maximum size of all receive buffers.
It is set by a user before any operation. If it was set to be
zero, ColdFire emulator would go into an infinite loop while
receiving data in mcf_fec_receive. Add check to avoid it.

Reported-by: Wjjzhang <wjjzhang@tencent.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Prasad J Pandit 2016-11-29 00:38:39 +05:30 committed by Jason Wang
parent bd8ef5060d
commit 77d54985b8

View File

@ -393,7 +393,7 @@ static void mcf_fec_write(void *opaque, hwaddr addr,
s->tx_descriptor = s->etdsr;
break;
case 0x188:
s->emrbr = value & 0x7f0;
s->emrbr = value > 0 ? value & 0x7F0 : 0x7F0;
break;
default:
hw_error("mcf_fec_write Bad address 0x%x\n", (int)addr);