Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault

From: Christoph Hellwig
Date: Mon Feb 25 2019 - 22:57:48 EST

On Fri, Feb 22, 2019 at 01:59:10PM -0800, Linus Torvalds wrote:
> On Fri, Feb 22, 2019 at 1:38 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
> >
> > Don't be surprised if we see more separation like this in the future too.
> Yes, with the whole meltdown fiasco, there's actually more pressure to
> add more support for separation of kernel/user address spaces. As Andy
> pointed out, it's been discussed as a future wish-list for x86-64 too.

S/390 is another example.

I've also proposed a RISC-V extension for it, including prototypes
for Rocketchip and Qemu, and a Linux kernel support, but it didn't go
any way.