From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55370) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1boRma-00088R-Ub for qemu-devel@nongnu.org; Mon, 26 Sep 2016 05:01:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1boRmV-0000Rq-OG for qemu-devel@nongnu.org; Mon, 26 Sep 2016 05:01:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38968) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1boRmV-0000RY-I4 for qemu-devel@nongnu.org; Mon, 26 Sep 2016 05:00:59 -0400 From: Jason Wang Date: Mon, 26 Sep 2016 16:59:33 +0800 Message-Id: <1474880375-22946-26-git-send-email-jasowang@redhat.com> In-Reply-To: <1474880375-22946-1-git-send-email-jasowang@redhat.com> References: <1474880375-22946-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PULL 25/27] net: mcf: limit buffer descriptor count List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org Cc: qemu-devel@nongnu.org, Prasad J Pandit , Jason Wang 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 Reviewed-by: Paolo Bonzini Signed-off-by: Jason Wang --- hw/net/mcf_fec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/hw/net/mcf_fec.c b/hw/net/mcf_fec.c index 0ee8ad9..d31fea1 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); -- 2.7.4