| Message ID | 4D3D0373.30003@dsn.okisemi.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com> Date: Mon, 24 Jan 2011 13:43:31 +0900 > This PCH_GBE driver had an issue that the receiving data is not normal. > This driver had not removed correctly the padding data > which the DMA include in receiving data. > > This patch fixed this issue. > > Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com> There are bugs in these changes: > if (skb_copy_flag) { /* recycle skb */ > struct sk_buff *new_skb; > new_skb = > - netdev_alloc_skb(netdev, > - length + NET_IP_ALIGN); > + netdev_alloc_skb(netdev, length); > if (new_skb) { > if (!skb_padding_flag) { > skb_reserve(new_skb, > - NET_IP_ALIGN); > + PCH_GBE_DMA_PADDING); > } > memcpy(new_skb->data, skb->data, > length); If "!skb_padding_flag" then you will write past the end of the SKB data in that memcpy. You cannot allocate only "length" then proceed to reserve PCH_GBE_DMA_PADDING and then add "length" worth of data on top of that. In such a cause you must allocate at least "length + PCH_GBE_DMA_PADDING". Furthermore you _MUST_ respect NET_IP_ALIGN. Some platforms set this value to "0", because otherwise performance suffers greatly. There are two seperate issues, removing the padding bytes provided by the device, and aligning the IP headers as wanted by the cpu architecutre. Therefore they should be handled seperately, and we therefore should still see references to NET_IP_ALIGN in your patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi David Thank you for your comment. I will confirm them and will submit the patch modified. Best regards Toshiharu Okada(OKI semiconductor) ----- Original Message ----- From: "David Miller" <davem@davemloft.net> To: <toshiharu-linux@dsn.okisemi.com> Cc: <netdev@vger.kernel.org>; <linux-kernel@vger.kernel.org>; <qi.wang@intel.com>; <yong.y.wang@intel.com>; <andrew.chih.howe.khor@intel.com>; <joel.clark@intel.com>; <kok.howg.ewe@intel.com> Sent: Wednesday, January 26, 2011 6:32 AM Subject: Re: [PATCH] pch_gbe: Fix the issue that the receiving data is not normal. From: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com> Date: Mon, 24 Jan 2011 13:43:31 +0900 > This PCH_GBE driver had an issue that the receiving data is not normal. > This driver had not removed correctly the padding data > which the DMA include in receiving data. > > This patch fixed this issue. > > Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com> There are bugs in these changes: > if (skb_copy_flag) { /* recycle skb */ > struct sk_buff *new_skb; > new_skb = > - netdev_alloc_skb(netdev, > - length + NET_IP_ALIGN); > + netdev_alloc_skb(netdev, length); > if (new_skb) { > if (!skb_padding_flag) { > skb_reserve(new_skb, > - NET_IP_ALIGN); > + PCH_GBE_DMA_PADDING); > } > memcpy(new_skb->data, skb->data, > length); If "!skb_padding_flag" then you will write past the end of the SKB data in that memcpy. You cannot allocate only "length" then proceed to reserve PCH_GBE_DMA_PADDING and then add "length" worth of data on top of that. In such a cause you must allocate at least "length + PCH_GBE_DMA_PADDING". Furthermore you _MUST_ respect NET_IP_ALIGN. Some platforms set this value to "0", because otherwise performance suffers greatly. There are two seperate issues, removing the padding bytes provided by the device, and aligning the IP headers as wanted by the cpu architecutre. Therefore they should be handled seperately, and we therefore should still see references to NET_IP_ALIGN in your patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/pch_gbe/pch_gbe_main.c b/drivers/net/pch_gbe/pch_gbe_main.c index 03a1d28..1bf2626 100644 --- a/drivers/net/pch_gbe/pch_gbe_main.c +++ b/drivers/net/pch_gbe/pch_gbe_main.c @@ -29,6 +29,7 @@ const char pch_driver_version[] = DRV_VERSION; #define PCH_GBE_SHORT_PKT 64 #define DSC_INIT16 0xC000 #define PCH_GBE_DMA_ALIGN 0 +#define PCH_GBE_DMA_PADDING 2 #define PCH_GBE_WATCHDOG_PERIOD (1 * HZ) /* watchdog time */ #define PCH_GBE_COPYBREAK_DEFAULT 256 #define PCH_GBE_PCI_BAR 1 @@ -1422,8 +1423,8 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter, pr_err("Receive CRC Error\n"); } else { /* get receive length */ - /* length convert[-3], padding[-2] */ - length = (rx_desc->rx_words_eob) - 3 - 2; + /* length convert[-3] */ + length = (rx_desc->rx_words_eob) - 3; /* Decide the data conversion method */ if (!adapter->rx_csum) { @@ -1443,12 +1444,11 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter, if (skb_copy_flag) { /* recycle skb */ struct sk_buff *new_skb; new_skb = - netdev_alloc_skb(netdev, - length + NET_IP_ALIGN); + netdev_alloc_skb(netdev, length); if (new_skb) { if (!skb_padding_flag) { skb_reserve(new_skb, - NET_IP_ALIGN); + PCH_GBE_DMA_PADDING); } memcpy(new_skb->data, skb->data, length); @@ -1465,12 +1465,15 @@ pch_gbe_clean_rx(struct pch_gbe_adapter *adapter, } if (skb_padding_flag) { memcpy(&tmp_packet[0], &skb->data[0], ETH_HLEN); - memcpy(&skb->data[NET_IP_ALIGN], &tmp_packet[0], - ETH_HLEN); - skb_reserve(skb, NET_IP_ALIGN); - + memcpy(&skb->data[PCH_GBE_DMA_PADDING], + &tmp_packet[0], ETH_HLEN); + skb_reserve(skb, PCH_GBE_DMA_PADDING); + /* The length includes padding length */ + length = length - PCH_GBE_DMA_PADDING; } + /* The length includes FCS length */ + length = length - ETH_FCS_LEN; /* update status of driver */ adapter->stats.rx_bytes += length; adapter->stats.rx_packets++;
This PCH_GBE driver had an issue that the receiving data is not normal. This driver had not removed correctly the padding data which the DMA include in receiving data. This patch fixed this issue. Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com> --- drivers/net/pch_gbe/pch_gbe_main.c | 21 ++++++++++++--------- 1 files changed, 12 insertions(+), 9 deletions(-)