From: Sonny Rao <sonnyrao@us.ibm.com>
To: netdev@vger.kernel.org
Cc: e1000-devel@lists.sf.net, Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: [PATCHv2] Add missing memory barriers to clean_rx_irq functions in Intel Drivers
Date: Tue, 27 Jul 2010 17:44:34 -0500 [thread overview]
Message-ID: <20100727224434.GN17248@us.ibm.com> (raw)
In-Reply-To: <20100727223452.GM17248@us.ibm.com>
Add missing memory barriers to clean_rx_irq functions in Intel Drivers
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.
v2: I missed the e100 the first time
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Sonny Rao <sonnyrao@us.ibm.com>
cc: stable <stable@kernel.org>
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) >>
Index: linux-2.6.35-rc5/drivers/net/e100.c
===================================================================
--- linux-2.6.35-rc5.orig/drivers/net/e100.c 2010-07-27 17:36:44.000000000 -0500
+++ linux-2.6.35-rc5/drivers/net/e100.c 2010-07-27 17:41:38.000000000 -0500
@@ -1928,6 +1928,7 @@ static int e100_rx_indicate(struct nic *
netif_printk(nic, rx_status, KERN_DEBUG, nic->netdev,
"status=0x%04X\n", rfd_status);
+ rmb(); /* read size after status bit */
/* If data isn't ready, nothing to indicate */
if (unlikely(!(rfd_status & cb_complete))) {
next prev parent reply other threads:[~2010-07-27 22:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-27 22:34 [PATCH] Add missing memory barriers to clean_rx_irq functions in Intel Drivers Sonny Rao
2010-07-27 22:41 ` Jeff Kirsher
2010-07-27 22:46 ` Sonny Rao
2010-07-27 22:49 ` Jeff Kirsher
2010-07-27 22:44 ` Sonny Rao [this message]
2010-07-27 22:45 ` [PATCHv2] " Jeff Kirsher
2010-07-27 22:51 ` Sonny Rao
2010-07-27 23:05 ` [PATCHv3] " Sonny Rao
2010-07-27 23:08 ` Jeff Kirsher
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