Revision dc280d93623927570da279e99393879dbbab39e7 authored by Thomas Gleixner on 21 December 2016, 19:19:49 UTC, committed by Thomas Gleixner on 25 December 2016, 09:47:42 UTC
Developers manage to overwrite states blindly without thought. That's fatal
and hard to debug. Add sanity checks to make it fail.

This requries to restructure the code so that the dynamic state allocation
happens in the same lock protected section as the actual store. Otherwise
the previous assignment of 'Reserved' to the name field would trigger the
overwrite check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192111.675234535@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 parent 59fefd0
Raw File
sky81452.c
/*
 * sky81452.c	SKY81452 MFD driver
 *
 * Copyright 2014 Skyworks Solutions Inc.
 * Author : Gyungoh Yoo <jack.yoo@skyworksinc.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/mfd/core.h>
#include <linux/mfd/sky81452.h>

static const struct regmap_config sky81452_config = {
	.reg_bits = 8,
	.val_bits = 8,
};

static int sky81452_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	const struct sky81452_platform_data *pdata = dev_get_platdata(dev);
	struct mfd_cell cells[2];
	struct regmap *regmap;
	int ret;

	if (!pdata) {
		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
		if (!pdata)
			return -ENOMEM;
	}

	regmap = devm_regmap_init_i2c(client, &sky81452_config);
	if (IS_ERR(regmap)) {
		dev_err(dev, "failed to initialize.err=%ld\n", PTR_ERR(regmap));
		return PTR_ERR(regmap);
	}

	i2c_set_clientdata(client, regmap);

	memset(cells, 0, sizeof(cells));
	cells[0].name = "sky81452-backlight";
	cells[0].of_compatible = "skyworks,sky81452-backlight";
	cells[0].platform_data = pdata->bl_pdata;
	cells[0].pdata_size = sizeof(*pdata->bl_pdata);
	cells[1].name = "sky81452-regulator";
	cells[1].platform_data = pdata->regulator_init_data;
	cells[1].pdata_size = sizeof(*pdata->regulator_init_data);

	ret = devm_mfd_add_devices(dev, -1, cells, ARRAY_SIZE(cells),
				   NULL, 0, NULL);
	if (ret)
		dev_err(dev, "failed to add child devices. err=%d\n", ret);

	return ret;
}

static const struct i2c_device_id sky81452_ids[] = {
	{ "sky81452" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, sky81452_ids);

#ifdef CONFIG_OF
static const struct of_device_id sky81452_of_match[] = {
	{ .compatible = "skyworks,sky81452", },
	{ }
};
MODULE_DEVICE_TABLE(of, sky81452_of_match);
#endif

static struct i2c_driver sky81452_driver = {
	.driver = {
		.name = "sky81452",
		.of_match_table = of_match_ptr(sky81452_of_match),
	},
	.probe = sky81452_probe,
	.id_table = sky81452_ids,
};

module_i2c_driver(sky81452_driver);

MODULE_DESCRIPTION("Skyworks SKY81452 MFD driver");
MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@skyworksinc.com>");
MODULE_LICENSE("GPL v2");
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