| From | Andy Lutomirski <> | Date | Wed, 12 Feb 2020 13:42:48 -0800 | Subject | Re: [PATCH 38/62] x86/sev-es: Handle instruction fetches from user-space |
| |
On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote: > > From: Joerg Roedel <jroedel@suse.de> > > When a #VC exception is triggered by user-space the instruction > decoder needs to read the instruction bytes from user addresses. > Enhance es_fetch_insn_byte() to safely fetch kernel and user > instruction bytes.
I realize that this is a somewhat arbitrary point in the series to complain about this, but: the kernel already has infrastructure to decode and fix up an instruction-based exception. See fixup_umip_exception(). Please refactor code so that you can share the same infrastructure rather than creating an entirely new thing.
FWIW, the fixup_umip_exception() code seems to have much more robust segment handling than yours :)
--Andy
|