Re: [PATCH] iommu-common: Do not try to deref a null iommu->lazy_flush() pointer when n < pool->hint

From: Andrew Morton
Date: Thu Sep 17 2015 - 17:41:32 EST


On Thu, 17 Sep 2015 17:32:13 -0400 Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx> wrote:

> On (09/17/15 14:26), Andrew Morton wrote:
> > Patch looks good.
> >
> > But I don't know which kernel versions need the fix. So, when fixing a
> > bug please always describe the end-user visible effects of that bug.
> > Under what circumstances did your kernel crash?
> >
>
> I had a sparc kernel that was crashing when I was trying to process
> some very large perf.data files- the crash happens when the scsi
> driver calls into dma_4v_map_sg and thus the iommu_tbl_range_alloc().

Cool, thanks.

> Do you need me to respin the patch with the above info in the
> commit id?

No, that's fine. I updated the changelog, added cc:stable and shall
send it upstream next week.
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