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
da9052_wdt.c
/*
* System monitoring driver for DA9052 PMICs.
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: Anthony Olech <Anthony.Olech@diasemi.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/time.h>
#include <linux/watchdog.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>
#define DA9052_DEF_TIMEOUT 4
#define DA9052_TWDMIN 256
struct da9052_wdt_data {
struct watchdog_device wdt;
struct da9052 *da9052;
unsigned long jpast;
};
static const struct {
u8 reg_val;
int time; /* Seconds */
} da9052_wdt_maps[] = {
{ 1, 2 },
{ 2, 4 },
{ 3, 8 },
{ 4, 16 },
{ 5, 32 },
{ 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
{ 6, 65 },
{ 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
{ 7, 131 },
};
static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9052 *da9052 = driver_data->da9052;
int ret, i;
/*
* Disable the Watchdog timer before setting
* new time out.
*/
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE, 0);
if (ret < 0) {
dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
ret);
return ret;
}
if (timeout) {
/*
* To change the timeout, da9052 needs to
* be disabled for at least 150 us.
*/
udelay(150);
/* Set the desired timeout */
for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
if (da9052_wdt_maps[i].time == timeout)
break;
if (i == ARRAY_SIZE(da9052_wdt_maps))
ret = -EINVAL;
else
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE,
da9052_wdt_maps[i].reg_val);
if (ret < 0) {
dev_err(da9052->dev,
"Failed to update timescale bit, %d\n", ret);
return ret;
}
wdt_dev->timeout = timeout;
driver_data->jpast = jiffies;
}
return 0;
}
static int da9052_wdt_start(struct watchdog_device *wdt_dev)
{
return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
}
static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
{
return da9052_wdt_set_timeout(wdt_dev, 0);
}
static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
{
struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9052 *da9052 = driver_data->da9052;
unsigned long msec, jnow = jiffies;
int ret;
/*
* We have a minimum time for watchdog window called TWDMIN. A write
* to the watchdog before this elapsed time should cause an error.
*/
msec = (jnow - driver_data->jpast) * 1000/HZ;
if (msec < DA9052_TWDMIN)
mdelay(msec);
/* Reset the watchdog timer */
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_WATCHDOG, 1 << 7);
if (ret < 0)
goto err_strobe;
/*
* FIXME: Reset the watchdog core, in general PMIC
* is supposed to do this
*/
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_WATCHDOG, 0 << 7);
err_strobe:
return ret;
}
static struct watchdog_info da9052_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9052 Watchdog",
};
static const struct watchdog_ops da9052_wdt_ops = {
.owner = THIS_MODULE,
.start = da9052_wdt_start,
.stop = da9052_wdt_stop,
.ping = da9052_wdt_ping,
.set_timeout = da9052_wdt_set_timeout,
};
static int da9052_wdt_probe(struct platform_device *pdev)
{
struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
struct da9052_wdt_data *driver_data;
struct watchdog_device *da9052_wdt;
int ret;
driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
GFP_KERNEL);
if (!driver_data) {
ret = -ENOMEM;
goto err;
}
driver_data->da9052 = da9052;
da9052_wdt = &driver_data->wdt;
da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
da9052_wdt->info = &da9052_wdt_info;
da9052_wdt->ops = &da9052_wdt_ops;
da9052_wdt->parent = &pdev->dev;
watchdog_set_drvdata(da9052_wdt, driver_data);
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE, 0);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
ret);
goto err;
}
ret = watchdog_register_device(&driver_data->wdt);
if (ret != 0) {
dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
ret);
goto err;
}
platform_set_drvdata(pdev, driver_data);
err:
return ret;
}
static int da9052_wdt_remove(struct platform_device *pdev)
{
struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);
watchdog_unregister_device(&driver_data->wdt);
return 0;
}
static struct platform_driver da9052_wdt_driver = {
.probe = da9052_wdt_probe,
.remove = da9052_wdt_remove,
.driver = {
.name = "da9052-watchdog",
},
};
module_platform_driver(da9052_wdt_driver);
MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
MODULE_DESCRIPTION("DA9052 SM Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-watchdog");
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