Re: [RFC PATCH 2/2] powerpc/64s: system call support for scv/rfscv instructions
From: Segher Boessenkool <hidden>
Date: 2020-05-05 22:12:58
From: Segher Boessenkool <hidden>
Date: 2020-05-05 22:12:58
Hi! On Thu, Apr 30, 2020 at 02:02:02PM +1000, Nicholas Piggin wrote:
Add support for the scv instruction on POWER9 and later CPUs.
Looks good to me in general :-)
For now this implements the zeroth scv vector 'scv 0', as identical to 'sc' system calls, with the exception that lr is not preserved, and it is 64-bit only. There may yet be changes made to this ABI, so it's for testing only.
What does it do with SF=0? I don't see how it is obviously not a security hole currently (but I didn't look too closely). Segher