Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
  tracing, net: fix net tree and tracing tree merge interaction
  tracing, powerpc: fix powerpc tree and tracing tree interaction
  ring-buffer: do not remove reader page from list on ring buffer free
  function-graph: allow unregistering twice
  trace: make argument 'mem' of trace_seq_putmem() const
  tracing: add missing 'extern' keywords to trace_output.h
  tracing: provide trace_seq_reserve()
  blktrace: print out BLK_TN_MESSAGE properly
  blktrace: extract duplidate code
  blktrace: fix memory leak when freeing struct blk_io_trace
  blktrace: fix blk_probes_ref chaos
  blktrace: make classic output more classic
  blktrace: fix off-by-one bug
  blktrace: fix the original blktrace
  blktrace: fix a race when creating blk_tree_root in debugfs
  blktrace: fix timestamp in binary output
  tracing, Text Edit Lock: cleanup
  tracing: filter fix for TRACE_EVENT_FORMAT events
  ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
  x86: kretprobe-booster interrupt emulation code fix
  ...

Fix up trivial conflicts in
 arch/parisc/include/asm/ftrace.h
 include/linux/memory.h
 kernel/extable.c
 kernel/module.c

1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index d0871bc0aca5..c750f65f9661 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;
 	}