Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index d0871bc0aca..c750f65f966 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -245,16 +245,31 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 #endif
 }
 
+static void print_disabled(struct seq_file *m)
+{
+	seq_puts(m, "#\n"
+		 "#  Stack tracer disabled\n"
+		 "#\n"
+		 "# To enable the stack tracer, either add 'stacktrace' to the\n"
+		 "# kernel command line\n"
+		 "# or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'\n"
+		 "#\n");
+}
+
 static int t_show(struct seq_file *m, void *v)
 {
 	long i;
 	int size;
 
 	if (v == SEQ_START_TOKEN) {
-		seq_printf(m, "        Depth   Size      Location"
+		seq_printf(m, "        Depth    Size   Location"
 			   "    (%d entries)\n"
-			   "        -----   ----      --------\n",
+			   "        -----    ----   --------\n",
 			   max_stack_trace.nr_entries);
+
+		if (!stack_tracer_enabled && !max_stack_size)
+			print_disabled(m);
+
 		return 0;
 	}