Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fdb372ed authored by Li Zefan's avatar Li Zefan Committed by Frederic Weisbecker
Browse files

tracing: Use seq file for trace_options 



Code simplification for reading trace_options.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
LKML-reference: <4B1DC4EF.3090106@cn.fujitsu.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent 91baf628

kernel/trace/trace.c

+17 −43
Original line number Diff line number Diff line
@@ -2316,67 +2316,32 @@ static const struct file_operations tracing_cpumask_fops = { 
	.write		= tracing_cpumask_write,

};



static ssize_t

tracing_trace_options_read(struct file *filp, char __user *ubuf,

		       size_t cnt, loff_t *ppos)

static int tracing_trace_options_show(struct seq_file *m, void *v)

{

	struct tracer_opt *trace_opts;

	u32 tracer_flags;

	int len = 0;

	char *buf;

	int r = 0;

	int i;





	/* calculate max size */

	for (i = 0; trace_options[i]; i++) {

		len += strlen(trace_options[i]);

		len += 3; /* "no" and newline */

	}



	mutex_lock(&trace_types_lock);

	tracer_flags = current_trace->flags->val;

	trace_opts = current_trace->flags->opts;



	/*

	 * Increase the size with names of options specific

	 * of the current tracer.

	 */

	for (i = 0; trace_opts[i].name; i++) {

		len += strlen(trace_opts[i].name);

		len += 3; /* "no" and newline */

	}



	/* +1 for \0 */

	buf = kmalloc(len + 1, GFP_KERNEL);

	if (!buf) {

		mutex_unlock(&trace_types_lock);

		return -ENOMEM;

	}



	for (i = 0; trace_options[i]; i++) {

		if (trace_flags & (1 << i))

			r += sprintf(buf + r, "%s\n", trace_options[i]);

			seq_printf(m, "%s\n", trace_options[i]);

		else

			r += sprintf(buf + r, "no%s\n", trace_options[i]);

			seq_printf(m, "no%s\n", trace_options[i]);

	}



	for (i = 0; trace_opts[i].name; i++) {

		if (tracer_flags & trace_opts[i].bit)

			r += sprintf(buf + r, "%s\n",

				trace_opts[i].name);

			seq_printf(m, "%s\n", trace_opts[i].name);

		else

			r += sprintf(buf + r, "no%s\n",

				trace_opts[i].name);

			seq_printf(m, "no%s\n", trace_opts[i].name);

	}

	mutex_unlock(&trace_types_lock);



	WARN_ON(r >= len + 1);



	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);



	kfree(buf);

	return r;

	return 0;

}



/* Try to assign a tracer specific option */
@@ -2471,9 +2436,18 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, 
	return cnt;

}



static int tracing_trace_options_open(struct inode *inode, struct file *file)

{

	if (tracing_disabled)

		return -ENODEV;

	return single_open(file, tracing_trace_options_show, NULL);

}



static const struct file_operations tracing_iter_fops = {

	.open		= tracing_open_generic,

	.read		= tracing_trace_options_read,

	.open		= tracing_trace_options_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

	.write		= tracing_trace_options_write,

};