Messages in this thread | | | Date | Fri, 11 Feb 2022 16:11:03 -0800 | From | Dave Hansen <> | Subject | Re: [PATCH 25/35] x86/cet/shstk: Add user-mode shadow stack support |
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On 2/11/22 16:07, Andy Lutomirski wrote: > On Fri, Feb 11, 2022, at 3:37 PM, Dave Hansen wrote: >> On 1/30/22 13:18, Rick Edgecombe wrote: >>> Add the user shadow stack MSRs to the xsave helpers, so they can be used >>> to implement the functionality. >> Do these MSRs ever affect kernel-mode operation? >> >> If so, we might need to switch them more aggressively at context-switch >> time like PKRU. >> >> If not, they can continue to be context-switched with the PASID state >> which does not affect kernel-mode operation. > PASID? PASID is all kinds of weird. I assume you mean switching it > with all the normal state.
I was grouping PASID along with the CET MSRs because they're the only supervisor state. But, yeah, it's all XRSTOR'd at the same spot right now, user or kernel.
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