Re: panic in dmar_remove_one_dev_info

[Jerry Snitselaar]

On Mon Dec 16 19, Jerry Snitselaar wrote:
> HP is seeing a panic on gen9 dl360 and dl560 while testing these other
> changes we've been eorking on. I just took an initial look, but have
> to run to a dentist appointment so couldn't dig too deep. It looks
> like the device sets dev->archdata.iommu to DEFER_DEVICE_DOMAIN_INFO
> in intel_iommu_add_device, and then it needs a private domain so
> dmar_remove_one_dev_info gets called. That code path ends up trying to
> use DEFER_DEVICE_DOMAIN_INFO as a pointer.  I don't need if there just
> needs to be a check in there to bail out if it sees
> DEFER_DEVICE_DOMAIN_INFO, or if something more is needed. I'll look
> at it some more when I get back home.
>
> Regards,
> Jerry

Hi Baolu,

Does this look sane?

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5163,7 +5163,8 @@ static void dmar_remove_one_dev_info(struct device *dev)
 
        spin_lock_irqsave(&device_domain_lock, flags);
        info = dev->archdata.iommu;
-       if (info)
+       if (info && info != DEFER_DEVICE_DOMAIN_INFO
+           && info != DUMMY_DEVICE_DOMAIN_INFO)
                __dmar_remove_one_dev_info(info);
        spin_unlock_irqrestore(&device_domain_lock, flags);
 }




Regards,
Jerry