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
wdt_pci.c
/*
* Industrial Computer Source PCI-WDT500/501 driver
*
* (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* 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.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Release 0.10.
*
* Fixes
* Dave Gregorich : Modularisation and minor bugs
* Alan Cox : Added the watchdog ioctl() stuff
* Alan Cox : Fixed the reboot problem (as noted by
* Matt Crocker).
* Alan Cox : Added wdt= boot option
* Alan Cox : Cleaned up copy/user stuff
* Tim Hockin : Added insmod parameters, comment cleanup
* Parameterized timeout
* JP Nollmann : Added support for PCI wdt501p
* Alan Cox : Split ISA and PCI cards into two drivers
* Jeff Garzik : PCI cleanups
* Tigran Aivazian : Restructured wdtpci_init_one() to handle
* failures
* Joel Becker : Added WDIOC_GET/SETTIMEOUT
* Zwane Mwaikambo : Magic char closing, locking changes,
* cleanups
* Matt Domsch : nowayout module option
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define WDT_IS_PCI
#include "wd501p.h"
/* We can only use 1 card due to the /dev/watchdog restriction */
static int dev_count;
static unsigned long open_lock;
static DEFINE_SPINLOCK(wdtpci_lock);
static char expect_close;
static resource_size_t io;
static int irq;
/* Default timeout */
#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
static int heartbeat = WD_TIMO;
static int wd_heartbeat;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat,
"Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
__MODULE_STRING(WD_TIMO) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/* Support for the Fan Tachometer on the PCI-WDT501 */
static int tachometer;
module_param(tachometer, int, 0);
MODULE_PARM_DESC(tachometer,
"PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
static int type = 500;
module_param(type, int, 0);
MODULE_PARM_DESC(type,
"PCI-WDT501 Card type (500 or 501 , default=500)");
/*
* Programming support
*/
static void wdtpci_ctr_mode(int ctr, int mode)
{
ctr <<= 6;
ctr |= 0x30;
ctr |= (mode << 1);
outb(ctr, WDT_CR);
udelay(8);
}
static void wdtpci_ctr_load(int ctr, int val)
{
outb(val & 0xFF, WDT_COUNT0 + ctr);
udelay(8);
outb(val >> 8, WDT_COUNT0 + ctr);
udelay(8);
}
/**
* wdtpci_start:
*
* Start the watchdog driver.
*/
static int wdtpci_start(void)
{
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
/*
* "pet" the watchdog, as Access says.
* This resets the clock outputs.
*/
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
Pulse on Terminal Count */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
inb(WDT_DC); /* Disable watchdog */
udelay(8);
outb(0, WDT_CLOCK); /* 2.0833MHz clock */
udelay(8);
inb(WDT_BUZZER); /* disable */
udelay(8);
inb(WDT_OPTONOTRST); /* disable */
udelay(8);
inb(WDT_OPTORST); /* disable */
udelay(8);
inb(WDT_PROGOUT); /* disable */
udelay(8);
wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
Square Wave Generator */
wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
Rate Generator */
wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1:
Retriggerable One-Shot */
wdtpci_ctr_load(0, 20833); /* count at 100Hz */
wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
/* DO NOT LOAD CTR2 on PCI card! -- JPN */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_stop:
*
* Stop the watchdog driver.
*/
static int wdtpci_stop(void)
{
unsigned long flags;
/* Turn the card off */
spin_lock_irqsave(&wdtpci_lock, flags);
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_ping:
*
* Reload counter one with the watchdog heartbeat. We don't bother
* reloading the cascade counter.
*/
static int wdtpci_ping(void)
{
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
/* Write a watchdog value */
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
Rate Generator */
wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_set_heartbeat:
* @t: the new heartbeat value that needs to be set.
*
* Set a new heartbeat value for the watchdog device. If the heartbeat
* value is incorrect we keep the old value and return -EINVAL.
* If successful we return 0.
*/
static int wdtpci_set_heartbeat(int t)
{
/* Arbitrary, can't find the card's limits */
if (t < 1 || t > 65535)
return -EINVAL;
heartbeat = t;
wd_heartbeat = t * 100;
return 0;
}
/**
* wdtpci_get_status:
* @status: the new status.
*
* Extract the status information from a WDT watchdog device. There are
* several board variants so we have to know which bits are valid. Some
* bits default to one and some to zero in order to be maximally painful.
*
* we then map the bits onto the status ioctl flags.
*/
static int wdtpci_get_status(int *status)
{
unsigned char new_status;
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
new_status = inb(WDT_SR);
spin_unlock_irqrestore(&wdtpci_lock, flags);
*status = 0;
if (new_status & WDC_SR_ISOI0)
*status |= WDIOF_EXTERN1;
if (new_status & WDC_SR_ISII1)
*status |= WDIOF_EXTERN2;
if (type == 501) {
if (!(new_status & WDC_SR_TGOOD))
*status |= WDIOF_OVERHEAT;
if (!(new_status & WDC_SR_PSUOVER))
*status |= WDIOF_POWEROVER;
if (!(new_status & WDC_SR_PSUUNDR))
*status |= WDIOF_POWERUNDER;
if (tachometer) {
if (!(new_status & WDC_SR_FANGOOD))
*status |= WDIOF_FANFAULT;
}
}
return 0;
}
/**
* wdtpci_get_temperature:
*
* Reports the temperature in degrees Fahrenheit. The API is in
* farenheit. It was designed by an imperial measurement luddite.
*/
static int wdtpci_get_temperature(int *temperature)
{
unsigned short c;
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
c = inb(WDT_RT);
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
*temperature = (c * 11 / 15) + 7;
return 0;
}
/**
* wdtpci_interrupt:
* @irq: Interrupt number
* @dev_id: Unused as we don't allow multiple devices.
*
* Handle an interrupt from the board. These are raised when the status
* map changes in what the board considers an interesting way. That means
* a failure condition occurring.
*/
static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
{
/*
* Read the status register see what is up and
* then printk it.
*/
unsigned char status;
spin_lock(&wdtpci_lock);
status = inb(WDT_SR);
udelay(8);
pr_crit("status %d\n", status);
if (type == 501) {
if (!(status & WDC_SR_TGOOD)) {
pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
udelay(8);
}
if (!(status & WDC_SR_PSUOVER))
pr_crit("PSU over voltage\n");
if (!(status & WDC_SR_PSUUNDR))
pr_crit("PSU under voltage\n");
if (tachometer) {
if (!(status & WDC_SR_FANGOOD))
pr_crit("Possible fan fault\n");
}
}
if (!(status & WDC_SR_WCCR)) {
#ifdef SOFTWARE_REBOOT
#ifdef ONLY_TESTING
pr_crit("Would Reboot\n");
#else
pr_crit("Initiating system reboot\n");
emergency_restart(NULL);
#endif
#else
pr_crit("Reset in 5ms\n");
#endif
}
spin_unlock(&wdtpci_lock);
return IRQ_HANDLED;
}
/**
* wdtpci_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t wdtpci_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
wdtpci_ping();
}
return count;
}
/**
* wdtpci_ioctl:
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features. We only actually usefully support
* querying capabilities and current status.
*/
static long wdtpci_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_heartbeat;
int status;
struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT|
WDIOF_MAGICCLOSE|
WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = "PCI-WDT500/501",
};
/* Add options according to the card we have */
ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
if (type == 501) {
ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
WDIOF_POWEROVER);
if (tachometer)
ident.options |= WDIOF_FANFAULT;
}
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
wdtpci_get_status(&status);
return put_user(status, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
wdtpci_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, p))
return -EFAULT;
if (wdtpci_set_heartbeat(new_heartbeat))
return -EINVAL;
wdtpci_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
default:
return -ENOTTY;
}
}
/**
* wdtpci_open:
* @inode: inode of device
* @file: file handle to device
*
* The watchdog device has been opened. The watchdog device is single
* open and on opening we load the counters. Counter zero is a 100Hz
* cascade, into counter 1 which downcounts to reboot. When the counter
* triggers counter 2 downcounts the length of the reset pulse which
* set set to be as long as possible.
*/
static int wdtpci_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &open_lock))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/*
* Activate
*/
wdtpci_start();
return nonseekable_open(inode, file);
}
/**
* wdtpci_release:
* @inode: inode to board
* @file: file handle to board
*
* The watchdog has a configurable API. There is a religious dispute
* between people who want their watchdog to be able to shut down and
* those who want to be sure if the watchdog manager dies the machine
* reboots. In the former case we disable the counters, in the latter
* case you have to open it again very soon.
*/
static int wdtpci_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
wdtpci_stop();
} else {
pr_crit("Unexpected close, not stopping timer!\n");
wdtpci_ping();
}
expect_close = 0;
clear_bit(0, &open_lock);
return 0;
}
/**
* wdtpci_temp_read:
* @file: file handle to the watchdog board
* @buf: buffer to write 1 byte into
* @count: length of buffer
* @ptr: offset (no seek allowed)
*
* Read reports the temperature in degrees Fahrenheit. The API is in
* fahrenheit. It was designed by an imperial measurement luddite.
*/
static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
size_t count, loff_t *ptr)
{
int temperature;
if (wdtpci_get_temperature(&temperature))
return -EFAULT;
if (copy_to_user(buf, &temperature, 1))
return -EFAULT;
return 1;
}
/**
* wdtpci_temp_open:
* @inode: inode of device
* @file: file handle to device
*
* The temperature device has been opened.
*/
static int wdtpci_temp_open(struct inode *inode, struct file *file)
{
return nonseekable_open(inode, file);
}
/**
* wdtpci_temp_release:
* @inode: inode to board
* @file: file handle to board
*
* The temperature device has been closed.
*/
static int wdtpci_temp_release(struct inode *inode, struct file *file)
{
return 0;
}
/**
* notify_sys:
* @this: our notifier block
* @code: the event being reported
* @unused: unused
*
* Our notifier is called on system shutdowns. We want to turn the card
* off at reboot otherwise the machine will reboot again during memory
* test or worse yet during the following fsck. This would suck, in fact
* trust me - if it happens it does suck.
*/
static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdtpci_stop();
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations wdtpci_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdtpci_write,
.unlocked_ioctl = wdtpci_ioctl,
.open = wdtpci_open,
.release = wdtpci_release,
};
static struct miscdevice wdtpci_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdtpci_fops,
};
static const struct file_operations wdtpci_temp_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = wdtpci_temp_read,
.open = wdtpci_temp_open,
.release = wdtpci_temp_release,
};
static struct miscdevice temp_miscdev = {
.minor = TEMP_MINOR,
.name = "temperature",
.fops = &wdtpci_temp_fops,
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdtpci_notifier = {
.notifier_call = wdtpci_notify_sys,
};
static int wdtpci_init_one(struct pci_dev *dev,
const struct pci_device_id *ent)
{
int ret = -EIO;
dev_count++;
if (dev_count > 1) {
pr_err("This driver only supports one device\n");
return -ENODEV;
}
if (type != 500 && type != 501) {
pr_err("unknown card type '%d'\n", type);
return -ENODEV;
}
if (pci_enable_device(dev)) {
pr_err("Not possible to enable PCI Device\n");
return -ENODEV;
}
if (pci_resource_start(dev, 2) == 0x0000) {
pr_err("No I/O-Address for card detected\n");
ret = -ENODEV;
goto out_pci;
}
if (pci_request_region(dev, 2, "wdt_pci")) {
pr_err("I/O address 0x%llx already in use\n",
(unsigned long long)pci_resource_start(dev, 2));
goto out_pci;
}
irq = dev->irq;
io = pci_resource_start(dev, 2);
if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
"wdt_pci", &wdtpci_miscdev)) {
pr_err("IRQ %d is not free\n", irq);
goto out_reg;
}
pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
(unsigned long long)io, irq);
/* Check that the heartbeat value is within its range;
if not reset to the default */
if (wdtpci_set_heartbeat(heartbeat)) {
wdtpci_set_heartbeat(WD_TIMO);
pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
WD_TIMO);
}
ret = register_reboot_notifier(&wdtpci_notifier);
if (ret) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
goto out_irq;
}
if (type == 501) {
ret = misc_register(&temp_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
TEMP_MINOR, ret);
goto out_rbt;
}
}
ret = misc_register(&wdtpci_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto out_misc;
}
pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);
if (type == 501)
pr_info("Fan Tachometer is %s\n",
tachometer ? "Enabled" : "Disabled");
ret = 0;
out:
return ret;
out_misc:
if (type == 501)
misc_deregister(&temp_miscdev);
out_rbt:
unregister_reboot_notifier(&wdtpci_notifier);
out_irq:
free_irq(irq, &wdtpci_miscdev);
out_reg:
pci_release_region(dev, 2);
out_pci:
pci_disable_device(dev);
goto out;
}
static void wdtpci_remove_one(struct pci_dev *pdev)
{
/* here we assume only one device will ever have
* been picked up and registered by probe function */
misc_deregister(&wdtpci_miscdev);
if (type == 501)
misc_deregister(&temp_miscdev);
unregister_reboot_notifier(&wdtpci_notifier);
free_irq(irq, &wdtpci_miscdev);
pci_release_region(pdev, 2);
pci_disable_device(pdev);
dev_count--;
}
static const struct pci_device_id wdtpci_pci_tbl[] = {
{
.vendor = PCI_VENDOR_ID_ACCESSIO,
.device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
},
{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
static struct pci_driver wdtpci_driver = {
.name = "wdt_pci",
.id_table = wdtpci_pci_tbl,
.probe = wdtpci_init_one,
.remove = wdtpci_remove_one,
};
module_pci_driver(wdtpci_driver);
MODULE_AUTHOR("JP Nollmann, Alan Cox");
MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
MODULE_LICENSE("GPL");
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