On Thu, Apr 25, 2019 at 2:56 PM James Bottomley <James.Bottomley@hansenpartnership.com> wrote:
On Thu, 2019-04-25 at 13:47 -0700, Jonathan Adams wrote:
> It looks like the MM track isn't full, and I think this topic is an
> important thing to discuss.

Mike just posted the RFC patches for this using a ROP gadget preventor
as a demo:

https://lore.kernel.org/linux-mm/1556228754-12996-1-git-send-email-rppt@linux.ibm.com

but, unfortunately, he won't be at LSF/MM.

James

Mike's proposal is quite different, and targeted at restricting ROP execution.
The work proposed by Jonathan is aimed to transparently restrict speculative execution to provide generic mitigation against Spectre-V1 gadgets (and similar) and potentially eliminate the current need for for page table switches under most syscalls due to Meltdown.