Re: [PATCH 10/18] maccess: unify the probe kernel arch hooks

From: Christoph Hellwig
Date: Tue May 19 2020 - 01:46:17 EST


On Thu, May 14, 2020 at 10:13:18AM +0900, Masami Hiramatsu wrote:
> > + bool strict)
> > {
> > long ret;
> > mm_segment_t old_fs = get_fs();
> >
> > + if (!probe_kernel_read_allowed(dst, src, size, strict))
> > + return -EFAULT;
>
> Could you make this return -ERANGE instead of -EFAULT so that
> the caller can notice that the address might be user space?

That is clearly a behavior change, so I don't want to mix it into
this patch. But I can add it as another patch at the end.