Messages in this thread | | | Subject | Re: [PATCH v23 00/28] Control-flow Enforcement: Shadow Stack | From | "Yu, Yu-cheng" <> | Date | Tue, 23 Mar 2021 14:03:41 -0700 |
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On 3/23/2021 1:49 PM, Peter Zijlstra wrote: > 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 >
I will move code around and separate it into shadow stack and ibt. Hopefully in the next iteration, things will be more organized.
Thanks, Yu-cheng
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