It is a matter of guest kernel policy what to do with offending userspace, and terminating said userspace may not be the action chosen.
Linux explicitly tolerates this case. Reported-by: Andy Lutomirski <[email protected]> Fixes: fdac951560 ("x86: clear EFLAGS.NT in SYSENTER entry path") Signed-off-by: Andrew Cooper <[email protected]> --- CC: Jan Beulich <[email protected]> CC: Roger Pau Monné <[email protected]> CC: Wei Liu <[email protected]> CC: Andy Lutomirski <[email protected]> --- xen/arch/x86/x86_64/entry.S | 1 - 1 file changed, 1 deletion(-) diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index 71a00e846b..44a110b9c8 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -313,7 +313,6 @@ UNLIKELY_START(nz, sysenter_nt_set) pushfq andl $~X86_EFLAGS_NT,(%rsp) popfq - xorl %eax,%eax UNLIKELY_END(sysenter_nt_set) testq %rax,%rax leal (,%rcx,TBF_INTERRUPT),%ecx -- 2.11.0
