From 2b7890e757bc42f963c835521c2657bd16d7b7d6 Mon Sep 17 00:00:00 2001 From: Jonas Jensen Date: Mon, 25 Aug 2014 16:22:40 +0200 Subject: [PATCH] net: moxa: continue loop on skb allocation failure If netdev_alloc_skb_ip_align() fails, subsequent code will try to dereference an invalid pointer. Continue to next descriptor on error. While we're at it, 1. eliminate the chance of an endless loop, replace the main loop with while(rx < budget) 2. use napi_complete() and remove the explicit napi_gro_flush() Signed-off-by: Jonas Jensen Signed-off-by: David S. Miller --- drivers/net/ethernet/moxa/moxart_ether.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c index 983d01949795..2f12c88c66ab 100644 --- a/drivers/net/ethernet/moxa/moxart_ether.c +++ b/drivers/net/ethernet/moxa/moxart_ether.c @@ -206,7 +206,7 @@ static int moxart_rx_poll(struct napi_struct *napi, int budget) int rx_head = priv->rx_head; int rx = 0; - while (1) { + while (rx < budget) { desc = priv->rx_desc_base + (RX_REG_DESC_SIZE * rx_head); desc0 = readl(desc + RX_REG_OFFSET_DESC0); @@ -218,7 +218,7 @@ static int moxart_rx_poll(struct napi_struct *napi, int budget) net_dbg_ratelimited("packet error\n"); priv->stats.rx_dropped++; priv->stats.rx_errors++; - continue; + goto rx_next; } len = desc0 & RX_DESC0_FRAME_LEN_MASK; @@ -235,6 +235,7 @@ static int moxart_rx_poll(struct napi_struct *napi, int budget) net_dbg_ratelimited("netdev_alloc_skb_ip_align failed\n"); priv->stats.rx_dropped++; priv->stats.rx_errors++; + goto rx_next; } memcpy(skb->data, priv->rx_buf[rx_head], len); @@ -249,18 +250,15 @@ static int moxart_rx_poll(struct napi_struct *napi, int budget) if (desc0 & RX_DESC0_MULTICAST) priv->stats.multicast++; +rx_next: writel(RX_DESC0_DMA_OWN, desc + RX_REG_OFFSET_DESC0); rx_head = RX_NEXT(rx_head); priv->rx_head = rx_head; - - if (rx >= budget) - break; } if (rx < budget) { - napi_gro_flush(napi, false); - __napi_complete(napi); + napi_complete(napi); } priv->reg_imr |= RPKT_FINISH_M; -- 2.20.1