[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, 14 insertions, 14 deletions

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;
 }