Subject: Re: linux-next: boot failure after merge of the dma-mapping tree

From: Christoph Hellwig <[email-masked]>
Date: Thu, 20 Aug 2020 17:49:41 +0200

On Thu, Aug 20, 2020 at 01:36:17AM -0700, Nicolin Chen wrote:
> Took a quick look -- the boundary_size is seemingly passed from
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/powerpc/kernel/iommu.c#n240
> 
> 	boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
> 			1 << tbl->it_page_shift);
> 
> Looks like an overflow happens due to (ULONG_MAX + 1). Should
> we fix here instead (or also)?

Yes, please.  I'll drop the patch again for now, but once we've
got this sorted out I'll readd it.