On Mon, Jul 05, 2021 at 02:47:36PM +0100, Robin Murphy wrote:
> On 2021-07-05 11:23, Dan Carpenter wrote:
> > [ Ancient code, but the bug seems real enough still. -dan ]
> >
> > Hello Upinder Malhi,
> >
> > The patch e3cf00d0a87f: "IB/usnic: Add Cisco VIC low-level hardware
> > driver" from Sep 10, 2013, leads to the following static checker
> > warning:
> >
> > drivers/iommu/iommu.c:2482 iommu_map()
> > warn: sleeping in atomic context
> >
> > drivers/infiniband/hw/usnic/usnic_uiom.c
> > 244 static int usnic_uiom_map_sorted_intervals(struct list_head *intervals,
> > 245 struct usnic_uiom_reg *uiomr)
> >
> > This function is always called from usnic_uiom_reg_get() which is holding
> > spin_lock(&pd->lock); so it can't sleep.
>
> FWIW back in those days it wasn't really well defined whether iommu_map()
> was callable from non-sleeping contexts (the arch/arm DMA API code relied on
> it, for instance). It was only formalised 2 years ago by 781ca2de89ba
> ("iommu: Add gfp parameter to iommu_ops::map") which introduced the
> might_sleep() check that's firing there. I guess these calls want to be
> updated to iommu_map_atomic() now.
Does this mean this driver doesn't work at all upstream? I would be
quite interested to delete it.
Jason
