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.