Re: [PATCH 0/3] Fix device_lock deadlock on two probe() paths

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, Aug 08, 2023 at 09:18:51PM +0100, Mark Brown wrote:
> On Tue, Aug 08, 2023 at 02:27:04PM -0300, Jason Gunthorpe wrote:
> > I missed two paths where __iommu_probe_device() can be called while
> > already holding the device_lock() for the device that is to be probed.
> > 
> > This causes a deadlock because __iommu_probe_device() will attempt to
> > re-acquire the lock.
> > 
> > Organize things so that these two paths can re-use the existing already
> > held device_lock by marking the call chains based on if the lock is held
> > or not.
> > 
> > This is an incremental on top of Joerg's next, but it could also be handled by
> > respinning the last patch in that series. Please let me know.
> 
> The issues this series fixes have been causing quite a bit of breakage
> in a range of CI systems (Arm's internal stuff, KernelCI and my personal
> CI).  Both the KernelCI bot and my colleague Aishwarya (CCed) bisected
> which pointed to this series so I've tested them - I didn't cover every
> board but this does fix at least some boots so:
> 
> Tested-by: Mark Brown <broonie@kernel.org>
> 
> It'd be great to get these fixes into -next, thanks for getting the
> patches out so quickly.

Yes, sorry about that, this series didn't get picked up by any arm testing
before getting merged..

Thanks,
Jason