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
arizona-i2c.c
/*
 * Arizona-i2c.c  --  Arizona I2C bus interface
 *
 * Copyright 2012 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <linux/mfd/arizona/core.h>

#include "arizona.h"

static int arizona_i2c_probe(struct i2c_client *i2c,
			     const struct i2c_device_id *id)
{
	struct arizona *arizona;
	const struct regmap_config *regmap_config = NULL;
	unsigned long type;
	int ret;

	if (i2c->dev.of_node)
		type = arizona_of_get_type(&i2c->dev);
	else
		type = id->driver_data;

	switch (type) {
	case WM5102:
		if (IS_ENABLED(CONFIG_MFD_WM5102))
			regmap_config = &wm5102_i2c_regmap;
		break;
	case WM5110:
	case WM8280:
		if (IS_ENABLED(CONFIG_MFD_WM5110))
			regmap_config = &wm5110_i2c_regmap;
		break;
	case WM8997:
		if (IS_ENABLED(CONFIG_MFD_WM8997))
			regmap_config = &wm8997_i2c_regmap;
		break;
	case WM8998:
	case WM1814:
		if (IS_ENABLED(CONFIG_MFD_WM8998))
			regmap_config = &wm8998_i2c_regmap;
		break;
	default:
		dev_err(&i2c->dev, "Unknown device type %ld\n", type);
		return -EINVAL;
	}

	if (!regmap_config) {
		dev_err(&i2c->dev,
			"No kernel support for device type %ld\n", type);
		return -EINVAL;
	}

	arizona = devm_kzalloc(&i2c->dev, sizeof(*arizona), GFP_KERNEL);
	if (arizona == NULL)
		return -ENOMEM;

	arizona->regmap = devm_regmap_init_i2c(i2c, regmap_config);
	if (IS_ERR(arizona->regmap)) {
		ret = PTR_ERR(arizona->regmap);
		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
			ret);
		return ret;
	}

	arizona->type = type;
	arizona->dev = &i2c->dev;
	arizona->irq = i2c->irq;

	return arizona_dev_init(arizona);
}

static int arizona_i2c_remove(struct i2c_client *i2c)
{
	struct arizona *arizona = dev_get_drvdata(&i2c->dev);

	arizona_dev_exit(arizona);

	return 0;
}

static const struct i2c_device_id arizona_i2c_id[] = {
	{ "wm5102", WM5102 },
	{ "wm5110", WM5110 },
	{ "wm8280", WM8280 },
	{ "wm8997", WM8997 },
	{ "wm8998", WM8998 },
	{ "wm1814", WM1814 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, arizona_i2c_id);

static struct i2c_driver arizona_i2c_driver = {
	.driver = {
		.name	= "arizona",
		.pm	= &arizona_pm_ops,
		.of_match_table	= of_match_ptr(arizona_of_match),
	},
	.probe		= arizona_i2c_probe,
	.remove		= arizona_i2c_remove,
	.id_table	= arizona_i2c_id,
};

module_i2c_driver(arizona_i2c_driver);

MODULE_DESCRIPTION("Arizona I2C bus interface");
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_LICENSE("GPL");
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