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

[Jason Wang]

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 

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 
Signed-off-by: Prasad J Pandit 
---
  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 


Applied, thanks.

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

[Paolo Bonzini]

On 22/09/2016 12:32, P J P wrote:
> From: Prasad J Pandit 
> 
> 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 
> Signed-off-by: Prasad J Pandit 
> ---
>  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