lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <bfeb7228-7d03-f7b4-98ce-3671bfa42cc5@gmail.com>
Date:   Mon, 18 May 2020 22:14:21 +0200
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Realtek linux nic maintainers <nic_swsd@...ltek.com>,
        David Miller <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: [PATCH net-next] r8169: make rtl_rx better readable

Avoid the goto from the rx error handling branch into the else branch,
and in general avoid having the main rx work in the else branch.
In addition ensure proper reverse xmas tree order of variables in the
for loop.

No functional change intended.

Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 99 +++++++++++------------
 1 file changed, 48 insertions(+), 51 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index e35820c72..e887ee1e3 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4413,15 +4413,17 @@ static inline void rtl8169_rx_csum(struct sk_buff *skb, u32 opts1)
 
 static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget)
 {
-	unsigned int cur_rx, rx_left;
-	unsigned int count;
+	unsigned int cur_rx, rx_left, count;
+	struct device *d = tp_to_dev(tp);
 
 	cur_rx = tp->cur_rx;
 
 	for (rx_left = min(budget, NUM_RX_DESC); rx_left > 0; rx_left--, cur_rx++) {
-		unsigned int entry = cur_rx % NUM_RX_DESC;
-		const void *rx_buf = page_address(tp->Rx_databuff[entry]);
+		unsigned int pkt_size, entry = cur_rx % NUM_RX_DESC;
 		struct RxDesc *desc = tp->RxDescArray + entry;
+		struct sk_buff *skb;
+		const void *rx_buf;
+		dma_addr_t addr;
 		u32 status;
 
 		status = le32_to_cpu(desc->opts1);
@@ -4443,62 +4445,57 @@ static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget
 				dev->stats.rx_length_errors++;
 			if (status & RxCRC)
 				dev->stats.rx_crc_errors++;
-			if (status & (RxRUNT | RxCRC) && !(status & RxRWT) &&
-			    dev->features & NETIF_F_RXALL) {
-				goto process_pkt;
-			}
-		} else {
-			unsigned int pkt_size;
-			struct sk_buff *skb;
-
-process_pkt:
-			pkt_size = status & GENMASK(13, 0);
-			if (likely(!(dev->features & NETIF_F_RXFCS)))
-				pkt_size -= ETH_FCS_LEN;
-			/*
-			 * The driver does not support incoming fragmented
-			 * frames. They are seen as a symptom of over-mtu
-			 * sized frames.
-			 */
-			if (unlikely(rtl8169_fragmented_frame(status))) {
-				dev->stats.rx_dropped++;
-				dev->stats.rx_length_errors++;
-				goto release_descriptor;
-			}
 
-			skb = napi_alloc_skb(&tp->napi, pkt_size);
-			if (unlikely(!skb)) {
-				dev->stats.rx_dropped++;
+			if (!(dev->features & NETIF_F_RXALL))
 				goto release_descriptor;
-			}
+			else if (status & RxRWT || !(status & (RxRUNT | RxCRC)))
+				goto release_descriptor;
+		}
 
-			dma_sync_single_for_cpu(tp_to_dev(tp),
-						le64_to_cpu(desc->addr),
-						pkt_size, DMA_FROM_DEVICE);
-			prefetch(rx_buf);
-			skb_copy_to_linear_data(skb, rx_buf, pkt_size);
-			skb->tail += pkt_size;
-			skb->len = pkt_size;
+		pkt_size = status & GENMASK(13, 0);
+		if (likely(!(dev->features & NETIF_F_RXFCS)))
+			pkt_size -= ETH_FCS_LEN;
 
-			dma_sync_single_for_device(tp_to_dev(tp),
-						   le64_to_cpu(desc->addr),
-						   pkt_size, DMA_FROM_DEVICE);
+		/* The driver does not support incoming fragmented frames.
+		 * They are seen as a symptom of over-mtu sized frames.
+		 */
+		if (unlikely(rtl8169_fragmented_frame(status))) {
+			dev->stats.rx_dropped++;
+			dev->stats.rx_length_errors++;
+			goto release_descriptor;
+		}
 
-			rtl8169_rx_csum(skb, status);
-			skb->protocol = eth_type_trans(skb, dev);
+		skb = napi_alloc_skb(&tp->napi, pkt_size);
+		if (unlikely(!skb)) {
+			dev->stats.rx_dropped++;
+			goto release_descriptor;
+		}
 
-			rtl8169_rx_vlan_tag(desc, skb);
+		addr = le64_to_cpu(desc->addr);
+		rx_buf = page_address(tp->Rx_databuff[entry]);
 
-			if (skb->pkt_type == PACKET_MULTICAST)
-				dev->stats.multicast++;
+		dma_sync_single_for_cpu(d, addr, pkt_size, DMA_FROM_DEVICE);
+		prefetch(rx_buf);
+		skb_copy_to_linear_data(skb, rx_buf, pkt_size);
+		skb->tail += pkt_size;
+		skb->len = pkt_size;
+		dma_sync_single_for_device(d, addr, pkt_size, DMA_FROM_DEVICE);
 
-			napi_gro_receive(&tp->napi, skb);
+		rtl8169_rx_csum(skb, status);
+		skb->protocol = eth_type_trans(skb, dev);
+
+		rtl8169_rx_vlan_tag(desc, skb);
+
+		if (skb->pkt_type == PACKET_MULTICAST)
+			dev->stats.multicast++;
+
+		napi_gro_receive(&tp->napi, skb);
+
+		u64_stats_update_begin(&tp->rx_stats.syncp);
+		tp->rx_stats.packets++;
+		tp->rx_stats.bytes += pkt_size;
+		u64_stats_update_end(&tp->rx_stats.syncp);
 
-			u64_stats_update_begin(&tp->rx_stats.syncp);
-			tp->rx_stats.packets++;
-			tp->rx_stats.bytes += pkt_size;
-			u64_stats_update_end(&tp->rx_stats.syncp);
-		}
 release_descriptor:
 		rtl8169_mark_to_asic(desc);
 	}
-- 
2.26.2

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ