Subject: Re: [NET-NEXT PATCH] ixgbe: fix dma mapping unbalance

From: Joerg Roedel <[email-masked]>
Date: Fri, 12 Dec 2008 12:31:47 +0100

Nice. I discoverd a couple more bugs in this driver while testing my
IOMMU code.
One bug can only be found with an hardware IOMMU. This seems to be a
use-after-free bug, at least I see IO_PAGE_FAULTS from the IOMMU
originating from this card. Maybe you can change the VT-d code so that
you can debug this issue.
I didn't found the time yet to do a v2 of my DMA-API debugging patches.
But I hope can will the time for this next week. Then you have something
in hand to debug the driver even further :)

Joerg

On Fri, Dec 12, 2008 at 01:51:05AM -0800, Jeff Kirsher wrote:
> From: Jesse Brandeburg <[email-masked]>
> 
> This issue was initially reported by Joerg Roedel <[email-masked]>
> It appears that ixgbe has had a long standing bug where it was
> unmapping a different size than it had mapped.

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