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Re: [Qemu-devel] [PATCH v2] net: mcf: limit buffer descriptor count
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v2] net: mcf: limit buffer descriptor count |
Date: |
Thu, 22 Sep 2016 12:33:05 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 |
On 22/09/2016 12:32, P J P wrote:
> From: Prasad J Pandit <address@hidden>
>
> 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 <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> 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 <address@hidden>