Re: [PATCH 0/4] Fix type confusion in page_table_check

From: Greg Kroah-Hartman
Date: Sat May 13 2023 - 05:51:05 EST


On Fri, May 12, 2023 at 12:19:09AM +0800, Ruihan Li wrote:
> On Thu, May 11, 2023 at 08:32:01AM -0700, Christoph Hellwig wrote:
> > On Thu, May 11, 2023 at 09:44:55PM +0800, Ruihan Li wrote:
> > > Christoph's patch perfectly fixes _one_ problem: kmalloc'ed memory
> > > cannot be mapped to user space. However, as I detailed in the commit
> > > message, this series of patches fixes _three_ problems.
> >
> > FYI, I agree with you. My simple patch was sent before reading
> > your new series, and is a strict subset of it.
>
> Thank you for the clarification.
>
> > > I have to say that the original code is quite buggy. In the
> > > gen_pool_dma_alloc path, there is no guarantee of page alignment.
> >
> > I also find this whole interface very problematic to start with,
> > but that's a separate discussion for later.
>
> Yes. I don't think hybrid allocation of DMA memory and normal memory in
> one function is a good thing, but currently there is no clear way to fix
> this. Mixing memory allocation and page allocation is another bad thing,
> and at least, my patch can (hopefully) solve the second (and much
> easier) issue.

Ok, I'll take these through the usb tree if I can get an ack for the
mm-specific patches. Or were you going to send a v2 series?

thanks,

greg k-h