rfkill: add WARN and BUG_ON paranoia (v2)

BUG_ON() and WARN() the heck out of buggy drivers calling into the rfkill
subsystem.

Also switch from WARN_ON(1) to the new descriptive WARN().

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 37 insertions, 13 deletions

diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index b630f358d674..910699c4e04f 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -76,6 +76,7 @@ static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
  */
 int register_rfkill_notifier(struct notifier_block *nb)
 {
+        BUG_ON(!nb);
         return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(register_rfkill_notifier);
@@ -91,6 +92,7 @@ EXPORT_SYMBOL_GPL(register_rfkill_notifier);
  */
 int unregister_rfkill_notifier(struct notifier_block *nb)
 {
+        BUG_ON(!nb);
         return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
@@ -202,6 +204,9 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
                  * RFKILL_STATE_HARD_BLOCKED */
                 break;
         default:
+                WARN(1, KERN_WARNING
+                        "rfkill: illegal state %d passed as parameter "
+                        "to rfkill_toggle_radio\n", state);
                 return -EINVAL;
         }
 
@@ -236,7 +241,11 @@ static void __rfkill_switch_all(const enum rfkill_type type,
 {
         struct rfkill *rfkill;
 
-        if (unlikely(state >= RFKILL_STATE_MAX))
+        if (WARN((state >= RFKILL_STATE_MAX || type >= RFKILL_TYPE_MAX),
+                        KERN_WARNING
+                        "rfkill: illegal state %d or type %d "
+                        "passed as parameter to __rfkill_switch_all\n",
+                        state, type))
                 return;
 
         rfkill_global_states[type].current_state = state;
@@ -334,7 +343,11 @@ int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
 {
         enum rfkill_state oldstate;
 
-        if (unlikely(state >= RFKILL_STATE_MAX))
+        BUG_ON(!rfkill);
+        if (WARN((state >= RFKILL_STATE_MAX),
+                        KERN_WARNING
+                        "rfkill: illegal state %d passed as parameter "
+                        "to rfkill_force_state\n", state))
                 return -EINVAL;
 
         mutex_lock(&rfkill->mutex);
@@ -593,10 +606,10 @@ static int rfkill_check_duplicity(const struct rfkill *rfkill)
         memset(seen, 0, sizeof(seen));
 
         list_for_each_entry(p, &rfkill_list, node) {
-                if (p == rfkill) {
-                        WARN_ON(1);
+                if (WARN((p == rfkill), KERN_WARNING
+                                "rfkill: illegal attempt to register "
+                                "an already registered rfkill struct\n"))
                         return -EEXIST;
-                }
                 set_bit(p->type, seen);
         }
 
@@ -664,6 +677,12 @@ struct rfkill * __must_check rfkill_allocate(struct device *parent,
         struct rfkill *rfkill;
         struct device *dev;
 
+        if (WARN((type >= RFKILL_TYPE_MAX),
+                        KERN_WARNING
+                        "rfkill: illegal type %d passed as parameter "
+                        "to rfkill_allocate\n", type))
+                return NULL;
+
         rfkill = kzalloc(sizeof(struct rfkill), GFP_KERNEL);
         if (!rfkill)
                 return NULL;
@@ -736,11 +755,12 @@ int __must_check rfkill_register(struct rfkill *rfkill)
         struct device *dev = &rfkill->dev;
         int error;
 
-        if (!rfkill->toggle_radio)
-                return -EINVAL;
-        if (rfkill->type >= RFKILL_TYPE_MAX)
-                return -EINVAL;
-        if (rfkill->state >= RFKILL_STATE_MAX)
+        if (WARN((!rfkill || !rfkill->toggle_radio ||
+                        rfkill->type >= RFKILL_TYPE_MAX ||
+                        rfkill->state >= RFKILL_STATE_MAX),
+                        KERN_WARNING
+                        "rfkill: attempt to register a "
+                        "badly initialized rfkill struct\n"))
                 return -EINVAL;
 
         snprintf(dev->bus_id, sizeof(dev->bus_id),
@@ -775,6 +795,7 @@ EXPORT_SYMBOL(rfkill_register);
  */
 void rfkill_unregister(struct rfkill *rfkill)
 {
+        BUG_ON(!rfkill);
         device_del(&rfkill->dev);
         rfkill_remove_switch(rfkill);
         rfkill_led_trigger_unregister(rfkill);
@@ -811,9 +832,12 @@ int rfkill_set_default(enum rfkill_type type, enum rfkill_state state)
 {
         int error;
 
-        if (type >= RFKILL_TYPE_MAX ||
-            (state != RFKILL_STATE_SOFT_BLOCKED &&
-             state != RFKILL_STATE_UNBLOCKED))
+        if (WARN((type >= RFKILL_TYPE_MAX ||
+                        (state != RFKILL_STATE_SOFT_BLOCKED &&
+                         state != RFKILL_STATE_UNBLOCKED)),
+                        KERN_WARNING
+                        "rfkill: illegal state %d or type %d passed as "
+                        "parameter to rfkill_set_default\n", state, type))
                 return -EINVAL;
 
         mutex_lock(&rfkill_mutex);