hw/net/allwinner-sun8i-emac.c: Fix REG_ADDR_HIGH/LOW reads

Coverity points out (CID 1421926) that the read code for
REG_ADDR_HIGH reads off the end of the buffer, because it does a
32-bit read from byte 4 of a 6-byte buffer.

The code also has an endianness issue for both REG_ADDR_HIGH and
REG_ADDR_LOW, because it will do the wrong thing on a big-endian
host.

Rewrite the read code to use ldl_le_p() and lduw_le_p() to fix this;
the write code is not incorrect, but for consistency we make it use
stl_le_p() and stw_le_p().

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Peter Maydell 2020-03-24 21:21:03 +00:00 committed by Jason Wang
parent 8ffb7265af
commit b88fb1247b

View File

@ -611,10 +611,10 @@ static uint64_t allwinner_sun8i_emac_read(void *opaque, hwaddr offset,
value = s->mii_data;
break;
case REG_ADDR_HIGH: /* MAC Address High */
value = *(((uint32_t *) (s->conf.macaddr.a)) + 1);
value = lduw_le_p(s->conf.macaddr.a + 4);
break;
case REG_ADDR_LOW: /* MAC Address Low */
value = *(uint32_t *) (s->conf.macaddr.a);
value = ldl_le_p(s->conf.macaddr.a);
break;
case REG_TX_DMA_STA: /* Transmit DMA Status */
break;
@ -728,14 +728,10 @@ static void allwinner_sun8i_emac_write(void *opaque, hwaddr offset,
s->mii_data = value;
break;
case REG_ADDR_HIGH: /* MAC Address High */
s->conf.macaddr.a[4] = (value & 0xff);
s->conf.macaddr.a[5] = (value & 0xff00) >> 8;
stw_le_p(s->conf.macaddr.a + 4, value);
break;
case REG_ADDR_LOW: /* MAC Address Low */
s->conf.macaddr.a[0] = (value & 0xff);
s->conf.macaddr.a[1] = (value & 0xff00) >> 8;
s->conf.macaddr.a[2] = (value & 0xff0000) >> 16;
s->conf.macaddr.a[3] = (value & 0xff000000) >> 24;
stl_le_p(s->conf.macaddr.a, value);
break;
case REG_TX_DMA_STA: /* Transmit DMA Status */
case REG_TX_CUR_DESC: /* Transmit Current Descriptor */