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Commit 85951842 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

ftrace: Don't increment @pos in g_start() 



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 larger than PAGE_SIZE.

Reviewed-by: default avatarLiming Wang <liming.wang@windriver.com>
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A418738.7090401@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f129e965

kernel/trace/ftrace.c

+10 −11
Original line number Original line Diff line number Diff line
@@ -2500,32 +2500,31 @@ int ftrace_graph_count; 
unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;

unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;





static void *

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;

	unsigned long *array = m->private;

	int index = *pos;



	(*pos)++;





	if (index >= ftrace_graph_count)

	if (*pos >= ftrace_graph_count)

		return NULL;

		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)

static void *g_start(struct seq_file *m, loff_t *pos)

{

{

	void *p = NULL;



	mutex_lock(&graph_lock);

	mutex_lock(&graph_lock);





	/* Nothing, tell g_show to print all functions are enabled */

	/* Nothing, tell g_show to print all functions are enabled */

	if (!ftrace_graph_count && !*pos)

	if (!ftrace_graph_count && !*pos)

		return (void *)1;

		return (void *)1;





	p = g_next(m, p, pos);

	return __g_next(m, pos);



	return p;

}

}





static void g_stop(struct seq_file *m, void *p)

static void g_stop(struct seq_file *m, void *p)