[RFC 2/3] arm64: refactor save_stack_trace()

[rostedt@goodmis.org (Steven Rostedt)]

On Thu, 16 Jul 2015 11:31:15 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> > 
> > In case of the number of entries, the following diff might be needed
> > as I suggested in the previous reply. ;)
> > 
> > ----8<----
> > 
> > @@ -330,7 +333,7 @@ static int t_show(struct seq_file *m, void *v)
> >  		seq_printf(m, "        Depth    Size   Location"
> >  			   "    (%d entries)\n"
> >  			   "        -----    ----   --------\n",
> > -			   max_stack_trace.nr_entries - 1);
> > +			   max_stack_trace.nr_entries);
> 
> This would break x86.

Nope, you were correct. But it was also missing another change:

-- Steve

Index: linux-trace.git/kernel/trace/trace_stack.c
===================================================================
--- linux-trace.git.orig/kernel/trace/trace_stack.c	2015-07-16 11:45:17.816249113 -0400
+++ linux-trace.git/kernel/trace/trace_stack.c	2015-07-16 12:01:51.051403333 -0400
@@ -284,7 +260,7 @@ __next(struct seq_file *m, loff_t *pos)
 {
 	long n = *pos - 1;
 
-	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
+	if (n > max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
 	m->private = (void *)n;
@@ -354,7 +330,7 @@ static int t_show(struct seq_file *m, vo
 		seq_printf(m, "        Depth    Size   Location"
 			   "    (%d entries)\n"
 			   "        -----    ----   --------\n",
-			   max_stack_trace.nr_entries - 1);
+			   max_stack_trace.nr_entries);
 
 		if (!stack_tracer_enabled && !max_stack_size)
 			print_disabled(m);