[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: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

5 files changed, 46 insertions, 47 deletions

diff --git a/drivers/char/watchdog/cpu5wdt.c b/drivers/char/watchdog/cpu5wdt.c
index bcd7e36ca0aa..d0d45a8b09f0 100644
--- a/drivers/char/watchdog/cpu5wdt.c
+++ b/drivers/char/watchdog/cpu5wdt.c
@@ -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;
 }
 
diff --git a/drivers/char/watchdog/eurotechwdt.c b/drivers/char/watchdog/eurotechwdt.c
index f70387f01b2b..b070324e27a6 100644
--- a/drivers/char/watchdog/eurotechwdt.c
+++ b/drivers/char/watchdog/eurotechwdt.c
@@ -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;
 }
 
diff --git a/drivers/char/watchdog/ibmasr.c b/drivers/char/watchdog/ibmasr.c
index 8195f5023d85..94155f6136c2 100644
--- a/drivers/char/watchdog/ibmasr.c
+++ b/drivers/char/watchdog/ibmasr.c
@@ -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;
 }
 
diff --git a/drivers/char/watchdog/machzwd.c b/drivers/char/watchdog/machzwd.c
index 76c7fa37fa6c..a0d27160c80e 100644
--- a/drivers/char/watchdog/machzwd.c
+++ b/drivers/char/watchdog/machzwd.c
@@ -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;
 }
 
diff --git a/drivers/char/watchdog/sbc8360.c b/drivers/char/watchdog/sbc8360.c
index 67ae42685e75..285d85289532 100644
--- a/drivers/char/watchdog/sbc8360.c
+++ b/drivers/char/watchdog/sbc8360.c
@@ -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;
 }