1. 19 May, 2017 2 commits
    • Brian Norris's avatar
      mwifiex: fixup error cases in mwifiex_add_virtual_intf() · 8535107a
      Brian Norris authored
      If we fail to add an interface in mwifiex_add_virtual_intf(), we might
      hit a BUG_ON() in the networking code, because we didn't tear things
      down properly. Among the problems:
      
       (a) when failing to allocate workqueues, we fail to unregister the
           netdev before calling free_netdev()
       (b) even if we do try to unregister the netdev, we're still holding the
           rtnl lock, so the device never properly unregistered; we'll be at
           state NETREG_UNREGISTERING, and then hit free_netdev()'s:
      	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
       (c) we're allocating some dependent resources (e.g., DFS workqueues)
           after we've registered the interface; this may or may not cause
           problems, but it's good practice to allocate these before registering
       (d) we're not even trying to unwind anything when mwifiex_send_cmd() or
           mwifiex_sta_init_cmd() fail
      
      To fix these issues, let's:
      
       * add a stacked set of error handling labels, to keep error handling
         consistent and properly ordered (resolving (a) and (d))
       * move the workqueue allocations before the registration (to resolve
         (c); also resolves (b) by avoiding error cases where we have to
         unregister)
      
      [Incidentally, it's pretty easy to interrupt the alloc_workqueue() in,
      e.g., the following:
      
        iw phy phy0 interface add mlan0 type station
      
      by sending it SIGTERM.]
      
      This bugfix covers commits like commit 7d652034 ("mwifiex: channel
      switch support for mwifiex"), but parts of this bug exist all the way
      back to the introduction of dynamic interface handling in commit
      93a1df48 ("mwifiex: add cfg80211 handlers add/del_virtual_intf").
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarBrian Norris <briannorris@chromium.org>
      Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
      8535107a
    • Brian Norris's avatar
      mwifiex: pcie: de-duplicate buffer allocation code · d41bf5c1
      Brian Norris authored
      This code was duplicated as part of the PCIe FLR code added to this
      driver. Let's de-duplicate it to:
      
       * make things easier to read (mwifiex_pcie_free_buffers() now has a
         corresponding mwifiex_pcie_alloc_buffers())
       * reduce likelihood of bugs
       * make error logging equally verbose
       * save lines of code!
      
      Also drop some of the commentary that isn't really needed.
      Signed-off-by: default avatarBrian Norris <briannorris@chromium.org>
      Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
      d41bf5c1
  2. 18 May, 2017 38 commits