From: Jeremy Fitzhardinge <jeremy@xensource.com>
Date: Fri, 29 Feb 2008 17:55:43 +0000 (+0100)
Subject: xen: mask out SEP from CPUID
X-Git-Tag: v2.6.25-rc4~132
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d40e705903397445c6861a0a56c23e5b2e8f9b9a;p=linux-2.6

xen: mask out SEP from CPUID

Fix 32-on-64 pvops kernel:

we don't want userspace using syscall/sysenter, even if the hypervisor
supports it, so mask it out from CPUID.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 49e5358f48..8b9ee27805 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -153,6 +153,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 	if (*ax == 1)
 		maskedx = ~((1 << X86_FEATURE_APIC) |  /* disable APIC */
 			    (1 << X86_FEATURE_ACPI) |  /* disable ACPI */
+			    (1 << X86_FEATURE_SEP)  |  /* disable SEP */
 			    (1 << X86_FEATURE_ACC));   /* thermal monitoring */
 
 	asm(XEN_EMULATE_PREFIX "cpuid"