From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55819) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bn1JY-0000e6-ED for qemu-devel@nongnu.org; Thu, 22 Sep 2016 06:33:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bn1JW-0004h6-0d for qemu-devel@nongnu.org; Thu, 22 Sep 2016 06:33:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60190) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bn1JV-0004gp-Ps for qemu-devel@nongnu.org; Thu, 22 Sep 2016 06:33:09 -0400 References: <1474540357-4272-1-git-send-email-ppandit@redhat.com> From: Paolo Bonzini Message-ID: <44a3404c-d5ad-9914-e57b-7ab8fca39acb@redhat.com> Date: Thu, 22 Sep 2016 12:33:05 +0200 MIME-Version: 1.0 In-Reply-To: <1474540357-4272-1-git-send-email-ppandit@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] net: mcf: limit buffer descriptor count List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: P J P , Qemu Developers Cc: Jason Wang , Li Qiang , Prasad J Pandit 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