Re: [PATCHv5] mac80211: fix NULL pointer dereference in ieee80211_compatible_rates

["Tomas Winkler" <tomasw@gmail.com>]

On Wed, May 21, 2008 at 6:08 PM, Johannes Berg
<johannes@sipsolutions.net> wrote:
>
>> static void ieee80211_rx_bss_put(struct net_device *dev,
>>                                  struct ieee80211_sta_bss *bss)
>> {
>>         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
>>
>>         local_bh_disable();
>>         if (!atomic_dec_and_lock(&bss->users, &local->sta_bss_lock)) {
>>                 local_bh_enable();
>>                 return;
>>         }
>>
>> ---- don't we miss  local_bh_enable(); here or spin_unlock_bh takes
>> care of this ---
>>
>>
>>         __ieee80211_rx_bss_hash_del(dev, bss);
>>         list_del(&bss->list);
>>         spin_unlock_bh(&local->sta_bss_lock);
>
> spin_unlock_bh takes care of it. The local_bh_disable() +
> atomic_dec_and_lock() is like spin_lock_bh() + atomic_dec() just with
> different atomicity guarantees.
>
> johannes
>
OK, thanks for explanation
Tomas