On Sun, 2008-09-28 at 01:47 -0600, Johannes Berg wrote: > On Sat, 2008-09-27 at 21:51 +0200, Jiri Slaby wrote: > > > BUG: scheduling while atomic: iwl3945/0/1154/0x00000002 > > > [<ffffffff80257315>] synchronize_rcu+0x35/0x40 > > > [<ffffffff80551d17>] sta_info_destroy+0x47/0x110 > > [<ffffffff80559156>] ieee80211_set_disassoc+0x146/0x250 > > [<ffffffff805593d5>] ieee80211_sta_req_auth+0x85/0x90 > > [<ffffffff8055b156>] ieee80211_notify_mac+0x56/0xa0 > > [<ffffffffa0054663>] iwl3945_bg_alive_start+0x2f3/0x360 [iwl3945] > > > I don't know who is responsible here. Maybe ieee80211_notify_mac? Citing: > > "It is illegal to block while in an RCU read-side critical section." from > > rcu_read_lock comments, but synchronize_rcu() in __ieee80211_key_todo() > > sleeps and few mutexes are locked and might_sleep() invoked on the path too. > > Yup, for sure. > > This is a combination of various things, when ieee80211_notify_mac was > added ieee80211_sta_req_auth didn't destroy the sta info, later they > fixed a different bug that started doing that and we all missed that it > was called from here... > > We can fix this by using RTNL locking instead, not sure though that'll > work because I don't know how iwl3945 calls this, I'll let Tomas deal > with it. Johannes, this scheduleing in atomic has nothing to do with the caller. iwl3945 already calls it in a workqueue. The problem is inside ieee80211_notify_mac(). Unfortunately, iwl3945/iwlagn turns to be the only user at this time. Thanks, -yi -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
