Re: [Qemu-devel] [PATCH v2] net: mcf: limit buffer descriptor count

[Jason Wang <jasowang@redhat.com>]

On 2016年09月22日 18:33, Paolo Bonzini wrote:
>
> On 22/09/2016 12:32, P J P wrote:
>> From: Prasad J Pandit <pjp@fedoraproject.org>
>>
>> ColdFire Fast Ethernet Controller uses buffer descriptors to manage
>> data flow to/fro receive & transmit queues. While transmitting
>> packets, it could continue to read buffer descriptors if a buffer
>> descriptor has length of zero and has crafted values in bd.flags.
>> Set upper limit to number of buffer descriptors.
>>
>> Reported-by: Li Qiang <liqiang6-s@360.cn>
>> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
>> ---
>>   hw/net/mcf_fec.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> Update per
>>    -> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg05284.html
>>
>> diff --git a/hw/net/mcf_fec.c b/hw/net/mcf_fec.c
>> index 7c0398e..6d3418e 100644
>> --- a/hw/net/mcf_fec.c
>> +++ b/hw/net/mcf_fec.c
>> @@ -23,6 +23,7 @@ do { printf("mcf_fec: " fmt , ## __VA_ARGS__); } while (0)
>>   #define DPRINTF(fmt, ...) do {} while(0)
>>   #endif
>>   
>> +#define FEC_MAX_DESC 1024
>>   #define FEC_MAX_FRAME_SIZE 2032
>>   
>>   typedef struct {
>> @@ -149,7 +150,7 @@ static void mcf_fec_do_tx(mcf_fec_state *s)
>>       uint32_t addr;
>>       mcf_fec_bd bd;
>>       int frame_size;
>> -    int len;
>> +    int len, descnt = 0;
>>       uint8_t frame[FEC_MAX_FRAME_SIZE];
>>       uint8_t *ptr;
>>   
>> @@ -157,7 +158,7 @@ static void mcf_fec_do_tx(mcf_fec_state *s)
>>       ptr = frame;
>>       frame_size = 0;
>>       addr = s->tx_descriptor;
>> -    while (1) {
>> +    while (descnt++ < FEC_MAX_DESC) {
>>           mcf_fec_read_bd(&bd, addr);
>>           DPRINTF("tx_bd %x flags %04x len %d data %08x\n",
>>                   addr, bd.flags, bd.length, bd.data);
>>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Applied, thanks.