lkml.org 
[lkml]   [2022]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 25/35] x86/cet/shstk: Add user-mode shadow stack support
    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.

    \
     
     \ /
      Last update: 2022-02-12 01:12    [W:5.594 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site