ftrace: Don't increment @pos in g_start() (85951842) · Commits · 戴 / test

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:

Liming Wang <liming.wang@windriver.com> Signed-off-by:

Li 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:

Ingo Molnar <mingo@elte.hu>

kernel/trace/ftrace.c

+10 −11

Original line number	Diff line number	Diff line
		@@ -2500,32 +2500,31 @@ 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)++;

		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)

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