On Fri, Mar 19, 2021 at 02:43:04PM -0700, Yu, Yu-cheng wrote: > On 3/16/2021 2:15 PM, Peter Zijlstra wrote: > > On Tue, Mar 16, 2021 at 08:10:26AM -0700, Yu-cheng Yu wrote: > > > Control-flow Enforcement (CET) is a new Intel processor feature that blocks > > > return/jump-oriented programming attacks. Details are in "Intel 64 and > > > IA-32 Architectures Software Developer's Manual" [1]. > > > > > > CET can protect applications and the kernel. This series enables only > > > application-level protection, and has three parts: > > > > > > - Shadow stack [2], > > > - Indirect branch tracking [3], and > > > - Selftests [4]. > > > > CET is marketing; afaict SS and IBT are 100% independent and there's no > > reason what so ever to have them share any code, let alone a Kconfig > > knob. > > > In fact, I think all of this would improve is you remove the CET name > > from all of this entirely. Put this series under CONFIG_X86_SHSTK (or > > _SS) and use CONFIG_X86_IBT for the other one. > > > > Similarly with the .c file. > > > > All this CET business is just pure confusion. > > > > What about this, we bring back CONFIG_X86_SHSTK and CONFIG_X86_IBT. > For the CET name itself, can we change it to CFE (Control Flow Enforcement), > or just CF? Carry Flag :-) > In signal handling, ELF header parsing and arch_prctl(), shadow stack and > IBT pretty much share the same code. It is better not to split them into > two sets of files. Aside from redoing the UAPI we're stuck with that I suppose :/ And since I think the CET name is all over the UAPI, you might as well keep it for the kernel part of it as well :-( But if there's sufficient !UAPI bits it might still make sense to also have ibt.c and shstk.c
