perf_counter: More paranoia settings

Rename the perf_counter_priv knob to perf_counter_paranoia (because
priv can be read as private, as opposed to privileged) and provide
one more level:

 0 - permissive
 1 - restrict cpu counters to privilidged contexts
 2 - restrict kernel-mode code counting and profiling

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 0c4bf86..344a659 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -916,9 +916,9 @@
 #ifdef CONFIG_PERF_COUNTERS
 	{
 		.ctl_name	= CTL_UNNUMBERED,
-		.procname	= "perf_counter_privileged",
-		.data		= &sysctl_perf_counter_priv,
-		.maxlen		= sizeof(sysctl_perf_counter_priv),
+		.procname	= "perf_counter_paranoid",
+		.data		= &sysctl_perf_counter_paranoid,
+		.maxlen		= sizeof(sysctl_perf_counter_paranoid),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},