1. 21 Apr, 2012 2 commits
    • Wenqi Ma's avatar
      net/hyperv: Adding cancellation to ensure rndis filter is closed · 792df872
      Wenqi Ma authored
      Although the network interface is down, the RX packets number which
      could be observed by ifconfig may keep on increasing.
      
      This is because the WORK scheduled in netvsc_set_multicast_list()
      may be executed after netvsc_close(). That means the rndis filter
      may be re-enabled by do_set_multicast() even if it was closed by
      netvsc_close().
      
      By canceling possible WORK before close the rndis filter, the issue
      could be never happened.
      Signed-off-by: default avatarWenqi Ma <wenqi_ma@trendmicro.com.cn>
      Reviewed-by: default avatarWei Yongjun <yongjun_wei@trendmicro.com.cn>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      792df872
    • Stephen Boyd's avatar
      ks8851: Fix mutex deadlock in ks8851_net_stop() · c5a99937
      Stephen Boyd authored
      There is a potential deadlock scenario when the ks8851 driver
      is removed. The interrupt handler schedules a workqueue which
      acquires a mutex that ks8851_net_stop() also acquires before
      flushing the workqueue. Previously lockdep wouldn't be able
      to find this problem but now that it has the support we can
      trigger this lockdep warning by rmmoding the driver after
      an ifconfig up.
      
      Fix the possible deadlock by disabling the interrupts in
      the chip and then release the lock across the workqueue
      flushing. The mutex is only there to proect the registers
      anyway so this should be ok.
      
      =======================================================
      [ INFO: possible circular locking dependency detected ]
      3.0.21-00021-g8b33780-dirty #2911
      -------------------------------------------------------
      rmmod/125 is trying to acquire lock:
       ((&ks->irq_work)){+.+...}, at: [<c019e0b8>] flush_work+0x0/0xac
      
      but task is already holding lock:
       (&ks->lock){+.+...}, at: [<bf00b850>] ks8851_net_stop+0x64/0x138 [ks8851]
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #1 (&ks->lock){+.+...}:
             [<c01b89c8>] __lock_acquire+0x940/0x9f8
             [<c01b9058>] lock_acquire+0x10c/0x130
             [<c083dbec>] mutex_lock_nested+0x68/0x3dc
             [<bf00bd48>] ks8851_irq_work+0x24/0x46c [ks8851]
             [<c019c580>] process_one_work+0x2d8/0x518
             [<c019cb98>] worker_thread+0x220/0x3a0
             [<c01a2ad4>] kthread+0x88/0x94
             [<c0107008>] kernel_thread_exit+0x0/0x8
      
      -> #0 ((&ks->irq_work)){+.+...}:
             [<c01b7984>] validate_chain+0x914/0x1018
             [<c01b89c8>] __lock_acquire+0x940/0x9f8
             [<c01b9058>] lock_acquire+0x10c/0x130
             [<c019e104>] flush_work+0x4c/0xac
             [<bf00b858>] ks8851_net_stop+0x6c/0x138 [ks8851]
             [<c06b209c>] __dev_close_many+0x98/0xcc
             [<c06b2174>] dev_close_many+0x68/0xd0
             [<c06b22ec>] rollback_registered_many+0xcc/0x2b8
             [<c06b2554>] rollback_registered+0x28/0x34
             [<c06b25b8>] unregister_netdevice_queue+0x58/0x7c
             [<c06b25f4>] unregister_netdev+0x18/0x20
             [<bf00c1f4>] ks8851_remove+0x64/0xb4 [ks8851]
             [<c049ddf0>] spi_drv_remove+0x18/0x1c
             [<c0468e98>] __device_release_driver+0x7c/0xbc
             [<c0468f64>] driver_detach+0x8c/0xb4
             [<c0467f00>] bus_remove_driver+0xb8/0xe8
             [<c01c1d20>] sys_delete_module+0x1e8/0x27c
             [<c0105ec0>] ret_fast_syscall+0x0/0x3c
      
      other info that might help us debug this:
      
       Possible unsafe locking scenario:
      
             CPU0                    CPU1
             ----                    ----
        lock(&ks->lock);
                                     lock((&ks->irq_work));
                                     lock(&ks->lock);
        lock((&ks->irq_work));
      
       *** DEADLOCK ***
      
      4 locks held by rmmod/125:
       #0:  (&__lockdep_no_validate__){+.+.+.}, at: [<c0468f44>] driver_detach+0x6c/0xb4
       #1:  (&__lockdep_no_validate__){+.+.+.}, at: [<c0468f50>] driver_detach+0x78/0xb4
       #2:  (rtnl_mutex){+.+.+.}, at: [<c06b25e8>] unregister_netdev+0xc/0x20
       #3:  (&ks->lock){+.+...}, at: [<bf00b850>] ks8851_net_stop+0x64/0x138 [ks8851]
      
      Cc: Ben Dooks <ben-linux@fluff.org>
      Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c5a99937
  2. 19 Apr, 2012 5 commits
  3. 18 Apr, 2012 12 commits
  4. 17 Apr, 2012 10 commits
  5. 16 Apr, 2012 2 commits
  6. 14 Apr, 2012 3 commits
  7. 13 Apr, 2012 6 commits