[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>

1 files changed, 11 insertions, 11 deletions

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;
 }