[PATCH 4/5] ftrace: don't increment @pos in g_start()

[Li Zefan <lizf@cn.fujitsu.com>]

It's wrong to increment @pos in g_start(). It causes some entries
lost when reading set_graph_function, if the output of the file
is large than PAGE_SIZE.

[ Impact: fix missing entries when reading set_graph_function ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/ftrace.c |   28 +++++++++++++---------------
 1 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ec18bb4..2c1c761 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2492,32 +2492,30 @@ int ftrace_graph_count;
 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
 
 static void *
-g_next(struct seq_file *m, void *v, loff_t *pos)
+__g_next(struct seq_file *m, loff_t *pos)
 {
 	unsigned long *array = m->private;
-	int index = *pos;
 
-	(*pos)++;
+	/* Nothing, tell g_show to print all functions are enabled */
+	if (!ftrace_graph_count && !*pos)
+		return (void *)1;
 
-	if (index >= ftrace_graph_count)
+	if (*pos >= ftrace_graph_count)
 		return NULL;
+	return &array[*pos];
+}
 
-	return &array[index];
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return __g_next(m, pos);
 }
 
 static void *g_start(struct seq_file *m, loff_t *pos)
 {
-	void *p = NULL;
-
 	mutex_lock(&graph_lock);
-
-	/* Nothing, tell g_show to print all functions are enabled */
-	if (!ftrace_graph_count && !*pos)
-		return (void *)1;
-
-	p = g_next(m, p, pos);
-
-	return p;
+	return __g_next(m, pos);
 }
 
 static void g_stop(struct seq_file *m, void *p)
-- 
1.5.4.rc3