2.6.39-stable review patch. If anyone has any objections, please let us know.
------------------ system dma mask From: Chris Wright <[email protected]> commit 8fcc5372fbac085199d84a880503ed67aba3fe49 upstream. The identity mapping code appears to make the assumption that if the devices dma_mask is greater than 32bits the device can use identity mapping. But that is not true: take the case where we have a 40bit device in a 44bit architecture. The device can potentially receive a physical address that it will truncate and cause incorrect addresses to be used. Instead check to see if the device's dma_mask is large enough to address the system's dma_mask. Signed-off-by: Mike Travis <[email protected]> Reviewed-by: Mike Habeck <[email protected]> Signed-off-by: David Woodhouse <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/pci/intel-iommu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -2190,8 +2190,19 @@ static int iommu_should_identity_map(str * Assume that they will -- if they turn out not to be, then we can * take them out of the 1:1 domain later. */ - if (!startup) - return pdev->dma_mask > DMA_BIT_MASK(32); + if (!startup) { + /* + * If the device's dma_mask is less than the system's memory + * size then this is not a candidate for identity mapping. + */ + u64 dma_mask = pdev->dma_mask; + + if (pdev->dev.coherent_dma_mask && + pdev->dev.coherent_dma_mask < dma_mask) + dma_mask = pdev->dev.coherent_dma_mask; + + return dma_mask >= dma_get_required_mask(&pdev->dev); + } return 1; } _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
