linux/drivers/watchdog/smsc37b787_wdt.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x
*
* Based on acquirewdt.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
* and some other existing drivers
*
* The authors do NOT admit liability nor provide warranty for
* any of this software. This material is provided "AS-IS" in
* the hope that it may be useful for others.
*
* (C) Copyright 2003-2006 Sven Anders <anders@anduras.de>
*
* History:
* 2003 - Created version 1.0 for Linux 2.4.x.
* 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
* features. Released version 1.1
*
* Theory of operation:
*
* A Watchdog Timer (WDT) is a hardware circuit that can
* reset the computer system in case of a software fault.
* You probably knew that already.
*
* Usually a userspace daemon will notify the kernel WDT driver
* via the /dev/watchdog special device file that userspace is
* still alive, at regular intervals. When such a notification
* occurs, the driver will usually tell the hardware watchdog
* that everything is in order, and that the watchdog should wait
* for yet another little while to reset the system.
* If userspace fails (RAM error, kernel bug, whatever), the
* notifications cease to occur, and the hardware watchdog will
* reset the system (causing a reboot) after the timeout occurs.
*
* Create device with:
* mknod /dev/watchdog c 10 130
*
* For an example userspace keep-alive daemon, see:
* Documentation/watchdog/wdt.rst
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/uaccess.h>
/* enable support for minutes as units? */
/* (does not always work correctly, so disabled by default!) */
#define SMSC_SUPPORT_MINUTES
#undef SMSC_SUPPORT_MINUTES
#define MAX_TIMEOUT 255
#define UNIT_SECOND 0
#define UNIT_MINUTE 1
#define VERSION "1.1"
#define IOPORT 0x3F0
#define IOPORT_SIZE 2
#define IODEV_NO 8
static int unit = UNIT_SECOND; /* timer's unit */
static int timeout = 60; /* timeout value: default is 60 "units" */
static unsigned long timer_enabled; /* is the timer enabled? */
static char expect_close; /* is the close expected? */
static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
static bool nowayout = WATCHDOG_NOWAYOUT;
/* -- Low level function ----------------------------------------*/
/* unlock the IO chip */
static inline void open_io_config(void)
{
outb(0x55, IOPORT);
mdelay(1);
outb(0x55, IOPORT);
}
/* lock the IO chip */
static inline void close_io_config(void)
{
outb(0xAA, IOPORT);
}
/* select the IO device */
static inline void select_io_device(unsigned char devno)
{
outb(0x07, IOPORT);
outb(devno, IOPORT+1);
}
/* write to the control register */
static inline void write_io_cr(unsigned char reg, unsigned char data)
{
outb(reg, IOPORT);
outb(data, IOPORT+1);
}
/* read from the control register */
static inline char read_io_cr(unsigned char reg)
{
outb(reg, IOPORT);
return inb(IOPORT+1);
}
/* -- Medium level functions ------------------------------------*/
static inline void gpio_bit12(unsigned char reg)
{
/* -- General Purpose I/O Bit 1.2 --
* Bit 0, In/Out: 0 = Output, 1 = Input
* Bit 1, Polarity: 0 = No Invert, 1 = Invert
* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
* Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17,
* 11 = Either Edge Triggered Intr. 2
* Bit 5/6 (Reserved)
* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
*/
write_io_cr(0xE2, reg);
}
static inline void gpio_bit13(unsigned char reg)
{
/* -- General Purpose I/O Bit 1.3 --
* Bit 0, In/Out: 0 = Output, 1 = Input
* Bit 1, Polarity: 0 = No Invert, 1 = Invert
* Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
* Bit 3, Function select: 0 = GPI/O, 1 = LED
* Bit 4-6 (Reserved)
* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
*/
write_io_cr(0xE3, reg);
}
static inline void wdt_timer_units(unsigned char new_units)
{
/* -- Watchdog timer units --
* Bit 0-6 (Reserved)
* Bit 7, WDT Time-out Value Units Select
* (0 = Minutes, 1 = Seconds)
*/
write_io_cr(0xF1, new_units);
}
static inline void wdt_timeout_value(unsigned char new_timeout)
{
/* -- Watchdog Timer Time-out Value --
* Bit 0-7 Binary coded units (0=Disabled, 1..255)
*/
write_io_cr(0xF2, new_timeout);
}
static inline void wdt_timer_conf(unsigned char conf)
{
/* -- Watchdog timer configuration --
* Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon
* Gameport I/O
* Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
* Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
* Bit 3 Reset the timer
* (Wrong in SMsC documentation? Given as: PowerLED Timout
* Enabled)
* Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
* 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
*/
write_io_cr(0xF3, conf);
}
static inline void wdt_timer_ctrl(unsigned char reg)
{
/* -- Watchdog timer control --
* Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
* Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz
* Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
* Bit 3 P20 Force Timeout enabled:
* 0 = P20 activity does not generate the WD timeout event
* 1 = P20 Allows rising edge of P20, from the keyboard
* controller, to force the WD timeout event.
* Bit 4 (Reserved)
* -- Soft power management --
* Bit 5 Stop Counter: 1 = Stop software power down counter
* set via register 0xB8, (self-cleaning)
* (Upon read: 0 = Counter running, 1 = Counter stopped)
* Bit 6 Restart Counter: 1 = Restart software power down counter
* set via register 0xB8, (self-cleaning)
* Bit 7 SPOFF: 1 = Force software power down (self-cleaning)
*/
write_io_cr(0xF4, reg);
}
/* -- Higher level functions ------------------------------------*/
/* initialize watchdog */
static void wb_smsc_wdt_initialize(void)
{
unsigned char old;
spin_lock(&io_lock);
open_io_config();
select_io_device(IODEV_NO);
/* enable the watchdog */
gpio_bit13(0x08); /* Select pin 80 = LED not GPIO */
gpio_bit12(0x0A); /* Set pin 79 = WDT not
GPIO/Output/Polarity=Invert */
/* disable the timeout */
wdt_timeout_value(0);
/* reset control register */
wdt_timer_ctrl(0x00);
/* reset configuration register */
wdt_timer_conf(0x00);
/* read old (timer units) register */
old = read_io_cr(0xF1) & 0x7F;
if (unit == UNIT_SECOND)
old |= 0x80; /* set to seconds */
/* set the watchdog timer units */
wdt_timer_units(old);
close_io_config();
spin_unlock(&io_lock);
}
/* shutdown the watchdog */
static void wb_smsc_wdt_shutdown(void)
{
spin_lock(&io_lock);
open_io_config();
select_io_device(IODEV_NO);
/* disable the watchdog */
gpio_bit13(0x09);
gpio_bit12(0x09);
/* reset watchdog config register */
wdt_timer_conf(0x00);
/* reset watchdog control register */
wdt_timer_ctrl(0x00);
/* disable timeout */
wdt_timeout_value(0x00);
close_io_config();
spin_unlock(&io_lock);
}
/* set timeout => enable watchdog */
static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)
{
spin_lock(&io_lock);
open_io_config();
select_io_device(IODEV_NO);
/* set Power LED to blink, if we enable the timeout */
wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02);
/* set timeout value */
wdt_timeout_value(new_timeout);
close_io_config();
spin_unlock(&io_lock);
}
/* get timeout */
static unsigned char wb_smsc_wdt_get_timeout(void)
{
unsigned char set_timeout;
spin_lock(&io_lock);
open_io_config();
select_io_device(IODEV_NO);
set_timeout = read_io_cr(0xF2);
close_io_config();
spin_unlock(&io_lock);
return set_timeout;
}
/* disable watchdog */
static void wb_smsc_wdt_disable(void)
{
/* set the timeout to 0 to disable the watchdog */
wb_smsc_wdt_set_timeout(0);
}
/* enable watchdog by setting the current timeout */
static void wb_smsc_wdt_enable(void)
{
/* set the current timeout... */
wb_smsc_wdt_set_timeout(timeout);
}
/* reset the timer */
static void wb_smsc_wdt_reset_timer(void)
{
spin_lock(&io_lock);
open_io_config();
select_io_device(IODEV_NO);
/* reset the timer */
wdt_timeout_value(timeout);
wdt_timer_conf(0x08);
close_io_config();
spin_unlock(&io_lock);
}
/* return, if the watchdog is enabled (timeout is set...) */
static int wb_smsc_wdt_status(void)
{
return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING;
}
/* -- File operations -------------------------------------------*/
/* open => enable watchdog and set initial timeout */
static int wb_smsc_wdt_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &timer_enabled))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Reload and activate timer */
wb_smsc_wdt_enable();
pr_info("Watchdog enabled. Timeout set to %d %s\n",
timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
*: convert stream-like files from nonseekable_open -> stream_open Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock"), search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Among cases converted 14 were potentially vulnerable to read vs write deadlock (see details in 10dce8af3422): drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. and the rest were just safe to convert to stream_open because their read and write do not use ppos at all and corresponding file_operations do not have methods that assume @offset file access(*): arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. One can also recheck/review the patch via generating it with explanation comments included via $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain" (*) This second group also contains cases with read/write deadlocks that stream_open.cocci don't yet detect, but which are still valid to convert to stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c calls wait_for_completion_interruptible() in its .read, but stream_open.cocci currently detects only "wait_event*" as blocking. Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Anatolij Gustschin <agust@denx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com> Cc: Corey Minyard <minyard@acm.org> Cc: Harald Welte <laforge@gnumonks.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs] Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Johan Hovold <johan@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Jean Delvare <jdelvare@suse.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [watchdog/* hwmon/*] Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec] Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec] Cc: Benson Leung <bleung@chromium.org> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome] Cc: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*] Cc: Mark Brown <broonie@kernel.org> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Zwane Mwaikambo <zwanem@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-03-26 20:51:19 +00:00
return stream_open(inode, file);
}
/* close => shut off the timer */
static int wb_smsc_wdt_release(struct inode *inode, struct file *file)
{
/* Shut off the timer. */
if (expect_close == 42) {
wb_smsc_wdt_disable();
pr_info("Watchdog disabled, sleeping again...\n");
} else {
pr_crit("Unexpected close, not stopping watchdog!\n");
wb_smsc_wdt_reset_timer();
}
clear_bit(0, &timer_enabled);
expect_close = 0;
return 0;
}
/* write => update the timer to keep the machine alive */
static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/* reset expect flag */
expect_close = 0;
/* scan to see whether or not we got the
magic character */
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
/* someone wrote to us, we should reload the timer */
wb_smsc_wdt_reset_timer();
}
return len;
}
/* ioctl => control interface */
static long wb_smsc_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
int new_timeout;
union {
struct watchdog_info __user *ident;
int __user *i;
} uarg;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "SMsC 37B787 Watchdog",
};
uarg.i = (int __user *)arg;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(uarg.ident, &ident, sizeof(ident))
? -EFAULT : 0;
case WDIOC_GETSTATUS:
return put_user(wb_smsc_wdt_status(), uarg.i);
case WDIOC_GETBOOTSTATUS:
return put_user(0, uarg.i);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, uarg.i))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
wb_smsc_wdt_disable();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
wb_smsc_wdt_enable();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
wb_smsc_wdt_reset_timer();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, uarg.i))
return -EFAULT;
/* the API states this is given in secs */
if (unit == UNIT_MINUTE)
new_timeout /= 60;
if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
return -EINVAL;
timeout = new_timeout;
wb_smsc_wdt_set_timeout(timeout);
/* fall through - and return the new timeout... */
case WDIOC_GETTIMEOUT:
new_timeout = timeout;
if (unit == UNIT_MINUTE)
new_timeout *= 60;
return put_user(new_timeout, uarg.i);
default:
return -ENOTTY;
}
}
/* -- Notifier funtions -----------------------------------------*/
static int wb_smsc_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT) {
/* set timeout to 0, to avoid possible race-condition */
timeout = 0;
wb_smsc_wdt_disable();
}
return NOTIFY_DONE;
}
/* -- Module's structures ---------------------------------------*/
static const struct file_operations wb_smsc_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wb_smsc_wdt_write,
.unlocked_ioctl = wb_smsc_wdt_ioctl,
.open = wb_smsc_wdt_open,
.release = wb_smsc_wdt_release,
};
static struct notifier_block wb_smsc_wdt_notifier = {
.notifier_call = wb_smsc_wdt_notify_sys,
};
static struct miscdevice wb_smsc_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wb_smsc_wdt_fops,
};
/* -- Module init functions -------------------------------------*/
/* module's "constructor" */
static int __init wb_smsc_wdt_init(void)
{
int ret;
pr_info("SMsC 37B787 watchdog component driver "
VERSION " initialising...\n");
if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
pr_err("Unable to register IO port %#x\n", IOPORT);
ret = -EBUSY;
goto out_pnp;
}
/* set new maximum, if it's too big */
if (timeout > MAX_TIMEOUT)
timeout = MAX_TIMEOUT;
/* init the watchdog timer */
wb_smsc_wdt_initialize();
ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
if (ret) {
pr_err("Unable to register reboot notifier err = %d\n", ret);
goto out_io;
}
ret = misc_register(&wb_smsc_wdt_miscdev);
if (ret) {
pr_err("Unable to register miscdev on minor %d\n",
WATCHDOG_MINOR);
goto out_rbt;
}
/* output info */
pr_info("Timeout set to %d %s\n",
timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
pr_info("Watchdog initialized and sleeping (nowayout=%d)...\n",
nowayout);
out_clean:
return ret;
out_rbt:
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
out_io:
release_region(IOPORT, IOPORT_SIZE);
out_pnp:
goto out_clean;
}
/* module's "destructor" */
static void __exit wb_smsc_wdt_exit(void)
{
/* Stop the timer before we leave */
if (!nowayout) {
wb_smsc_wdt_shutdown();
pr_info("Watchdog disabled\n");
}
misc_deregister(&wb_smsc_wdt_miscdev);
unregister_reboot_notifier(&wb_smsc_wdt_notifier);
release_region(IOPORT, IOPORT_SIZE);
pr_info("SMsC 37B787 watchdog component driver removed\n");
}
module_init(wb_smsc_wdt_init);
module_exit(wb_smsc_wdt_exit);
MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version "
VERSION ")");
MODULE_LICENSE("GPL");
#ifdef SMSC_SUPPORT_MINUTES
module_param(unit, int, 0);
MODULE_PARM_DESC(unit,
"set unit to use, 0=seconds or 1=minutes, default is 0");
#endif
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");