Re: [syzbot] [iommu?] kernel BUG in dma_alloc_attrs

[Sean Anderson]

On 10/16/24 04:02, Christoph Hellwig wrote:
> The problem is that the dma alloc/free tracing calls virt_to_phys
> on the allocated/free memory.  But that memory can be vmalloced as
> in this case.  I think we don't have weirdo allocators or pools any
> more that are neither in the direct kernel mapping or vmalloc, so
> we might be able to do an
> 
> 		if (is_vmalloc_addr())
> 			page_to_phys(vmalloc_to_page()))

Do we need offset_in_page?

> 		else
> 			virt_to_page()
> 
> here.  Or just switch to tracing the virtual address to always be
> on the safe side.
> 

Since this function returns a virtual address, I think that would be
fine.

--Sean