This patch is similar to what was fixed in ixgbe in this patch: http://marc.info/?l=e1000-devel&m=126593062701537&w=3
We should add read memory barriers to all the similar cases across the Intel ethernet driver family. In the case of ixgbevf I've also added a missing barrier to the clean_tx_irq path because I missed it in my last patch. Without the barrier a processor can speculate a load ahead of the load which looks at the status bit and get stale information causing a number of different issues including invalid packet length, NULL pointers, or bad data since checksumming was assumed to be done in hardware. Signed-off-by: Milton Miller <[email protected]> Signed-off-by: Sonny Rao <[email protected]> cc: stable <[email protected]> Index: linux-2.6.35-rc5/drivers/net/e1000/e1000_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/e1000/e1000_main.c 2010-07-27 16:15:18.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/e1000/e1000_main.c 2010-07-27 16:22:21.000000000 -0500 @@ -3638,6 +3638,7 @@ static bool e1000_clean_jumbo_rx_irq(str if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; @@ -3844,6 +3845,7 @@ static bool e1000_clean_rx_irq(struct e1 if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; Index: linux-2.6.35-rc5/drivers/net/e1000e/netdev.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/e1000e/netdev.c 2010-07-27 16:22:38.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/e1000e/netdev.c 2010-07-27 16:25:23.000000000 -0500 @@ -774,6 +774,7 @@ static bool e1000_clean_rx_irq(struct e1 if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; @@ -1081,6 +1082,7 @@ static bool e1000_clean_rx_irq_ps(struct break; (*work_done)++; skb = buffer_info->skb; + rmb(); /* read descriptor and rx_buffer_info after status DD */ /* in the packet split case this is header only */ prefetch(skb->data - NET_IP_ALIGN); @@ -1280,6 +1282,7 @@ static bool e1000_clean_jumbo_rx_irq(str if (*work_done >= work_to_do) break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; Index: linux-2.6.35-rc5/drivers/net/ixgb/ixgb_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/ixgb/ixgb_main.c 2010-07-27 16:27:23.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/ixgb/ixgb_main.c 2010-07-27 16:41:57.000000000 -0500 @@ -1977,6 +1977,7 @@ ixgb_clean_rx_irq(struct ixgb_adapter *a break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; skb = buffer_info->skb; buffer_info->skb = NULL; Index: linux-2.6.35-rc5/drivers/net/ixgbevf/ixgbevf_main.c =================================================================== --- linux-2.6.35-rc5.orig/drivers/net/ixgbevf/ixgbevf_main.c 2010-07-27 16:30:51.000000000 -0500 +++ linux-2.6.35-rc5/drivers/net/ixgbevf/ixgbevf_main.c 2010-07-27 16:40:19.000000000 -0500 @@ -231,6 +231,7 @@ static bool ixgbevf_clean_tx_irq(struct while ((eop_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)) && (count < tx_ring->work_limit)) { bool cleaned = false; + rmb(); /* read buffer_info after eop_desc */ for ( ; !cleaned; count++) { struct sk_buff *skb; tx_desc = IXGBE_TX_DESC_ADV(*tx_ring, i); @@ -518,6 +519,7 @@ static bool ixgbevf_clean_rx_irq(struct break; (*work_done)++; + rmb(); /* read descriptor and rx_buffer_info after status DD */ if (adapter->flags & IXGBE_FLAG_RX_PS_ENABLED) { hdr_info = le16_to_cpu(ixgbevf_get_hdr_info(rx_desc)); len = (hdr_info & IXGBE_RXDADV_HDRBUFLEN_MASK) >> ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://ad.doubleclick.net/clk;226879339;13503038;l? http://clk.atdmt.com/CRS/go/247765532/direct/01/ _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
