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Commit 6a10108b authored by Namhyung Kim's avatar Namhyung Kim Committed by Steven Rostedt
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ftrace: Narrow down the protected area of graph_lock 

The parser set up is just a generic utility that uses local variables
allocated by the function. There's no need to hold the graph_lock for
this set up.

This also makes the code simpler.

Link: http://lkml.kernel.org/r/1381739066-7531-4-git-send-email-namhyung@kernel.org



Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent faf982a6

kernel/trace/ftrace.c

+9 −13
Original line number Diff line number Diff line
@@ -3973,37 +3973,33 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, 
		   size_t cnt, loff_t *ppos)

{

	struct trace_parser parser;

	ssize_t read, ret;

	ssize_t read, ret = 0;

	struct ftrace_graph_data *fgd = file->private_data;



	if (!cnt)

		return 0;



	mutex_lock(&graph_lock);



	if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {

		ret = -ENOMEM;

		goto out_unlock;

	}

	if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))

		return -ENOMEM;



	read = trace_get_user(&parser, ubuf, cnt, ppos);



	if (read >= 0 && trace_parser_loaded((&parser))) {

		parser.buffer[parser.idx] = 0;



		mutex_lock(&graph_lock);



		/* we allow only one expression at a time */

		ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,

				      parser.buffer);

		if (ret)

			goto out_free;



		mutex_unlock(&graph_lock);

	}



	if (!ret)

		ret = read;



out_free:

	trace_parser_put(&parser);

out_unlock:

	mutex_unlock(&graph_lock);



	return ret;

}