1. 16 Jun, 2010 20 commits
  2. 15 Jun, 2010 19 commits
  3. 14 Jun, 2010 1 commit
    • Juuso Oikarinen's avatar
      mac80211: Fix circular locking dependency in ARP filter handling · 68542962
      Juuso Oikarinen authored
      There is a circular locking dependency when configuring the
      hardware ARP filters on association, occurring when flushing the mac80211
      workqueue. This is what happens:
      
      [   92.026800] =======================================================
      [   92.030507] [ INFO: possible circular locking dependency detected ]
      [   92.030507] 2.6.34-04781-g2b2c009e #85
      [   92.030507] -------------------------------------------------------
      [   92.030507] modprobe/5225 is trying to acquire lock:
      [   92.030507]  ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8105b5c0>] flush_workq
      ueue+0x0/0xb0
      [   92.030507]
      [   92.030507] but task is already holding lock:
      [   92.030507]  (rtnl_mutex){+.+.+.}, at: [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
      [   92.030507]
      [   92.030507] which lock already depends on the new lock.
      [   92.030507]
      [   92.030507]
      [   92.030507] the existing dependency chain (in reverse order) is:
      [   92.030507]
      [   92.030507] -> #2 (rtnl_mutex){+.+.+.}:
      [   92.030507]        [<ffffffff810761fb>] lock_acquire+0xdb/0x110
      [   92.030507]        [<ffffffff81341754>] mutex_lock_nested+0x44/0x300
      [   92.030507]        [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
      [   92.030507]        [<ffffffffa022d47c>] ieee80211_assoc_done+0x6c/0xe0 [mac80211]
      [   92.030507]        [<ffffffffa022f2ad>] ieee80211_work_work+0x31d/0x1280 [mac80211]
      
      [   92.030507] -> #1 ((&local->work_work)){+.+.+.}:
      [   92.030507]        [<ffffffff810761fb>] lock_acquire+0xdb/0x110
      [   92.030507]        [<ffffffff8105a51a>] worker_thread+0x22a/0x370
      [   92.030507]        [<ffffffff8105ecc6>] kthread+0x96/0xb0
      [   92.030507]        [<ffffffff81003a94>] kernel_thread_helper+0x4/0x10
      [   92.030507]
      [   92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}:
      [   92.030507]        [<ffffffff81075fdc>] __lock_acquire+0x1c0c/0x1d50
      [   92.030507]        [<ffffffff810761fb>] lock_acquire+0xdb/0x110
      [   92.030507]        [<ffffffff8105b60e>] flush_workqueue+0x4e/0xb0
      [   92.030507]        [<ffffffffa023ff7b>] ieee80211_stop_device+0x2b/0xb0 [mac80211]
      [   92.030507]        [<ffffffffa0231635>] ieee80211_stop+0x3e5/0x680 [mac80211]
      
      The locking in this case is quite complex. Fix the problem by rewriting the
      way the hardware ARP filter list is handled - i.e. make a copy of the address
      list to the bss_conf struct, and provide that list to the hardware driver
      when needed.
      
      The current patch will enable filtering also in promiscuous mode. This may need
      to be changed in the future.
      Reported-by: default avatarReinette Chatre <reinette.chatre@intel.com>
      Signed-off-by: default avatarJuuso Oikarinen <juuso.oikarinen@nokia.com>
      Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
      68542962