From: Andrea Arcangeli <andrea@cpushare.com>
Subject: [PATCH seccomp: make tsc disabling optional
Patch-mainline: unknown
References: 191123

Make the TSC disable purely paranoid feature optional, so by default seccomp
returns absolutely zerocost.

This only applies to i386.

Ported from 2.6.19 to 2.6.24-rc7 by Jeff Mahoney.

Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Acked-by: Jeff Mahoney <jeffm@suse.com>
Automatically created from "patches.fixes/seccomp-disable-tsc-option" by xen-port-patches.py

Index: head-2008-04-15/arch/x86/kernel/process_32-xen.c
===================================================================
--- head-2008-04-15.orig/arch/x86/kernel/process_32-xen.c	2008-04-15 10:47:44.000000000 +0200
+++ head-2008-04-15/arch/x86/kernel/process_32-xen.c	2008-04-15 10:47:49.000000000 +0200
@@ -441,6 +441,7 @@ static void hard_disable_TSC(void)
 }
 void disable_TSC(void)
 {
+#ifdef CONFIG_SECCOMP_DISABLE_TSC
 	preempt_disable();
 	if (!test_and_set_thread_flag(TIF_NOTSC))
 		/*
@@ -449,6 +450,7 @@ void disable_TSC(void)
 		 */
 		hard_disable_TSC();
 	preempt_enable();
+#endif
 }
 static void hard_enable_TSC(void)
 {