Re: [PATCH] iommu: Handle iommu faults for a bad iopf setup

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Aug 15, 2024 at 12:56:24PM +0000, Pranjal Shrivastava wrote:
> On Thu, Aug 15, 2024 at 09:46:11AM -0300, Jason Gunthorpe wrote:
> > On Thu, Aug 15, 2024 at 12:42:14PM +0000, Pranjal Shrivastava wrote:
> > 
> > > >  	if (!(fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) {
> > > >  		report_partial_fault(iopf_param, fault);
> > > 
> > > Apologies, I sent out an older version that missed returning a value.
> > > Please ignore this email, I'll resend the updated version.
> > 
> > It is probably Ok, the merge should resolve it.
> > 
> > The fix is already in linux-next:
> > 
> > commit fca5b78511e98bdff2cdd55c172b23200a7b3404
> > Author: Barak Biber <bbiber@nvidia.com>
> > Date:   Thu Aug 1 09:26:04 2024 -0300
> > 
> >     iommu: Restore lost return in iommu_report_device_fault()
> >     
> >     When iommu_report_device_fault gets called with a partial fault it is
> >     supposed to collect the fault into the group and then return.
> >     
> >     Instead the return was accidently deleted which results in trying to
> >     process the fault and an eventual crash.
> >     
> >     Deleting the return was a typo, put it back.
> >     
> >     Fixes: 3dfa64aecbaf ("iommu: Make iommu_report_device_fault() return void")
> >     Signed-off-by: Barak Biber <bbiber@nvidia.com>
> >     Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> >     Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
> >     Link: https://lore.kernel.org/r/0-v1-e7153d9c8cee+1c6-iommu_fault_fix_jgg@nvidia.com
> >     Signed-off-by: Joerg Roedel <jroedel@suse.de>
> > 
> > 
> > But doesn't look like it made it to rc3 yet
> 
> I guess it's there on as it gave me a build error as the `return;`
> statement was returning void for a non-void function. Fixed this and
> sent it as a v2 of this patch.

Oh I see now, yes, that is the right thing to do! 

You should also put [PATCH rc] so Joerg knows this is for rc as we are
fixing a regression in this merge window.

Jason