On Fri, 2022-10-14 at 18:20 +0200, Borislav Petkov wrote: > On Thu, Sep 29, 2022 at 03:29:00PM -0700, Rick Edgecombe wrote: > > From: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> > > > > The Control-Flow Enforcement Technology contains two related > > features, > > one of which is Shadow Stacks. Future patches will utilize this > > feature > > for shadow stack support in KVM, so add a CPU feature flags for > > Shadow > > Stacks (CPUID.(EAX=7,ECX=0):ECX[bit 7]). > > > > To protect shadow stack state from malicious modification, the > > registers > > are only accessible in supervisor mode. This implementation > > context-switches the registers with XSAVES. Make X86_FEATURE_SHSTK > > depend > > on XSAVES. > > > > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> > > Co-developed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> > > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> > > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > > Reviewed-by: Borislav Petkov <bp@xxxxxxx> Thanks!