Patchwork [NET-NEXT] ixgb: fix bug when freeing resources

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Submitter Jeff Kirsher
Date Oct. 1, 2008, 9:59 p.m.
Message ID <20081001215927.21799.53359.stgit@gitlost.lost>
Download mbox | patch
Permalink /patch/2309/
State Accepted
Delegated to: Jeff Garzik
Headers show

Comments

Jeff Kirsher - Oct. 1, 2008, 9:59 p.m.
From: Jesse Brandeburg <jesse.brandeburg@intel.com>

It was pointed out by Breno Leitao <leitao@linux.vnet.ibm.com> that
ixgb would crash on PPC when an IOMMU was in use, if change_mtu was
called.

It appears to be a pretty simple issue in the driver that wasn't discovered
because most systems don't run with an IOMMU.  The driver needs to only unmap
buffers that are mapped (duh).

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Breno Leitao <leitao@linux.vnet.ibm.com>
---

 drivers/net/ixgb/ixgb_main.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)


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Patch

diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index aa75385..be3c7dc 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -977,15 +977,17 @@  ixgb_clean_rx_ring(struct ixgb_adapter *adapter)
 
 	for (i = 0; i < rx_ring->count; i++) {
 		buffer_info = &rx_ring->buffer_info[i];
-		if (buffer_info->skb) {
-
+		if (buffer_info->dma) {
 			pci_unmap_single(pdev,
 					 buffer_info->dma,
 					 buffer_info->length,
 					 PCI_DMA_FROMDEVICE);
+			buffer_info->dma = 0;
+			buffer_info->length = 0;
+		}
 
+		if (buffer_info->skb) {
 			dev_kfree_skb(buffer_info->skb);
-
 			buffer_info->skb = NULL;
 		}
 	}