From 64c39517b5d2c2f324b87e7d663b184fca528d39 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 20 Oct 2020 14:41:48 +0200 Subject: [PATCH] x86/pv: Don't deliver #GP for a SYSENTER with NT set 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 Fixes: fdac951560 ("x86: clear EFLAGS.NT in SYSENTER entry path") Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich master commit: 61d4a04349895edc5a5868274b906ba61ef24f47 master date: 2020-09-24 21:02:35 +0100 --- 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 7510212956..000eb9722b 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 -- 2.30.2