Commit fb8f7ba0 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Wim Van Sebroeck
Browse files

[WATCHDOG] Semi-typical watchdog bug re early misc_register() 



It seems that some watchdog drivers are doing following mistake:

	rv = misc_register();
	if (rv < 0)
		return rv;
	rv = request_region();
	if (rv < 0) {
		misc_deregister();
		return rv;
	}

But, right after misc_register() returns, misc device can be opened and
ioctls interacting with hardware issued, and driver can do outb() to
port it doesn't own yet, because request_region() is still pending.

Here is my patch, compile-tested only.

Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 0e94f2ee

drivers/char/watchdog/cpu5wdt.c

+7 −7
Original line number Diff line number Diff line
@@ -220,17 +220,17 @@ static int __devinit cpu5wdt_init(void) 
	if ( verbose )

		printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);



	if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {

		printk(KERN_ERR PFX "misc_register failed\n");

		goto no_misc;

	}



	if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {

		printk(KERN_ERR PFX "request_region failed\n");

		err = -EBUSY;

		goto no_port;

	}



	if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {

		printk(KERN_ERR PFX "misc_register failed\n");

		goto no_misc;

	}



	/* watchdog reboot? */

	val = inb(port + CPU5WDT_STATUS_REG);

	val = (val >> 2) & 1;
@@ -250,9 +250,9 @@ static int __devinit cpu5wdt_init(void) 


	return 0;



no_port:

	misc_deregister(&cpu5wdt_misc);

no_misc:

	release_region(port, CPU5WDT_EXTENT);

no_port:

	return err;

}

drivers/char/watchdog/eurotechwdt.c

+11 −11
Original line number Diff line number Diff line
@@ -413,17 +413,10 @@ static int __init eurwdt_init(void) 
{

	int ret;



	ret = misc_register(&eurwdt_miscdev);

	if (ret) {

		printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",

		WATCHDOG_MINOR);

		goto out;

	}



	ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL);

	if(ret) {

		printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);

		goto outmisc;

		goto out;

	}



	if (!request_region(io, 2, "eurwdt")) {
@@ -438,6 +431,13 @@ static int __init eurwdt_init(void) 
		goto outreg;

	}



	ret = misc_register(&eurwdt_miscdev);

	if (ret) {

		printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",

		WATCHDOG_MINOR);

		goto outreboot;

	}



	eurwdt_unlock_chip();



	ret = 0;
@@ -448,14 +448,14 @@ static int __init eurwdt_init(void) 
out:

	return ret;



outreboot:

	unregister_reboot_notifier(&eurwdt_notifier);



outreg:

	release_region(io, 2);



outirq:

	free_irq(irq, NULL);



outmisc:

	misc_deregister(&eurwdt_miscdev);

	goto out;

}

drivers/char/watchdog/ibmasr.c

+5 −6
Original line number Diff line number Diff line
@@ -367,18 +367,17 @@ static int __init ibmasr_init(void) 
	if (!asr_type)

		return -ENODEV;



	rc = asr_get_base_address();

	if (rc)

		return rc;



	rc = misc_register(&asr_miscdev);

	if (rc < 0) {

		release_region(asr_base, asr_length);

		printk(KERN_ERR PFX "failed to register misc device\n");

		return rc;

	}



	rc = asr_get_base_address();

	if (rc) {

		misc_deregister(&asr_miscdev);

		return rc;

	}



	return 0;

}

drivers/char/watchdog/machzwd.c

+9 −9
Original line number Diff line number Diff line
@@ -440,13 +440,6 @@ static int __init zf_init(void) 
	spin_lock_init(&zf_lock);

	spin_lock_init(&zf_port_lock);



	ret = misc_register(&zf_miscdev);

	if (ret){

		printk(KERN_ERR "can't misc_register on minor=%d\n",

							WATCHDOG_MINOR);

		goto out;

	}



	if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){

		printk(KERN_ERR "cannot reserve I/O ports at %d\n",

							ZF_IOBASE);
@@ -461,16 +454,23 @@ static int __init zf_init(void) 
		goto no_reboot;

	}



	ret = misc_register(&zf_miscdev);

	if (ret){

		printk(KERN_ERR "can't misc_register on minor=%d\n",

							WATCHDOG_MINOR);

		goto no_misc;

	}



	zf_set_status(0);

	zf_set_control(0);



	return 0;



no_misc:

	unregister_reboot_notifier(&zf_notifier);

no_reboot:

	release_region(ZF_IOBASE, 3);

no_region:

	misc_deregister(&zf_miscdev);

out:

	return ret;

}

drivers/char/watchdog/sbc8360.c

+14 −14
Original line number Diff line number Diff line
@@ -333,18 +333,17 @@ static int __init sbc8360_init(void) 
	int res;

	unsigned long int mseconds = 60000;



	spin_lock_init(&sbc8360_lock);

	res = misc_register(&sbc8360_miscdev);

	if (res) {

		printk(KERN_ERR PFX "failed to register misc device\n");

		goto out_nomisc;

	if (timeout < 0 || timeout > 63) {

		printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n");

		res = -EINVAL;

		goto out;

	}



	if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) {

		printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n",

		       SBC8360_ENABLE);

		res = -EIO;

		goto out_noenablereg;

		goto out;

	}

	if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) {

		printk(KERN_ERR PFX
@@ -360,10 +359,11 @@ static int __init sbc8360_init(void) 
		goto out_noreboot;

	}



	if (timeout < 0 || timeout > 63) {

		printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n");

		res = -EINVAL;

		goto out_noreboot;

	spin_lock_init(&sbc8360_lock);

	res = misc_register(&sbc8360_miscdev);

	if (res) {

		printk(KERN_ERR PFX "failed to register misc device\n");

		goto out_nomisc;

	}



	wd_margin = wd_times[timeout][0];
@@ -383,13 +383,13 @@ static int __init sbc8360_init(void) 


	return 0;



      out_nomisc:

	unregister_reboot_notifier(&sbc8360_notifier);

      out_noreboot:

	release_region(SBC8360_ENABLE, 1);

	release_region(SBC8360_BASETIME, 1);

      out_noenablereg:

      out_nobasetimereg:

	misc_deregister(&sbc8360_miscdev);

      out_nomisc:

	release_region(SBC8360_ENABLE, 1);

      out:

	return res;

}

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