1. 11 Mar, 2022 38 commits
  2. 10 Mar, 2022 2 commits
    • Ivan Vecera's avatar
      ice: Fix race condition during interface enslave · 5cb1ebdb
      Ivan Vecera authored
      Commit 5dbbbd01 ("ice: Avoid RTNL lock when re-creating
      auxiliary device") changes a process of re-creation of aux device
      so ice_plug_aux_dev() is called from ice_service_task() context.
      This unfortunately opens a race window that can result in dead-lock
      when interface has left LAG and immediately enters LAG again.
      
      Reproducer:
      ```
      #!/bin/sh
      
      ip link add lag0 type bond mode 1 miimon 100
      ip link set lag0
      
      for n in {1..10}; do
              echo Cycle: $n
              ip link set ens7f0 master lag0
              sleep 1
              ip link set ens7f0 nomaster
      done
      ```
      
      This results in:
      [20976.208697] Workqueue: ice ice_service_task [ice]
      [20976.213422] Call Trace:
      [20976.215871]  __schedule+0x2d1/0x830
      [20976.219364]  schedule+0x35/0xa0
      [20976.222510]  schedule_preempt_disabled+0xa/0x10
      [20976.227043]  __mutex_lock.isra.7+0x310/0x420
      [20976.235071]  enum_all_gids_of_dev_cb+0x1c/0x100 [ib_core]
      [20976.251215]  ib_enum_roce_netdev+0xa4/0xe0 [ib_core]
      [20976.256192]  ib_cache_setup_one+0x33/0xa0 [ib_core]
      [20976.261079]  ib_register_device+0x40d/0x580 [ib_core]
      [20976.266139]  irdma_ib_register_device+0x129/0x250 [irdma]
      [20976.281409]  irdma_probe+0x2c1/0x360 [irdma]
      [20976.285691]  auxiliary_bus_probe+0x45/0x70
      [20976.289790]  really_probe+0x1f2/0x480
      [20976.298509]  driver_probe_device+0x49/0xc0
      [20976.302609]  bus_for_each_drv+0x79/0xc0
      [20976.306448]  __device_attach+0xdc/0x160
      [20976.310286]  bus_probe_device+0x9d/0xb0
      [20976.314128]  device_add+0x43c/0x890
      [20976.321287]  __auxiliary_device_add+0x43/0x60
      [20976.325644]  ice_plug_aux_dev+0xb2/0x100 [ice]
      [20976.330109]  ice_service_task+0xd0c/0xed0 [ice]
      [20976.342591]  process_one_work+0x1a7/0x360
      [20976.350536]  worker_thread+0x30/0x390
      [20976.358128]  kthread+0x10a/0x120
      [20976.365547]  ret_from_fork+0x1f/0x40
      ...
      [20976.438030] task:ip              state:D stack:    0 pid:213658 ppid:213627 flags:0x00004084
      [20976.446469] Call Trace:
      [20976.448921]  __schedule+0x2d1/0x830
      [20976.452414]  schedule+0x35/0xa0
      [20976.455559]  schedule_preempt_disabled+0xa/0x10
      [20976.460090]  __mutex_lock.isra.7+0x310/0x420
      [20976.464364]  device_del+0x36/0x3c0
      [20976.467772]  ice_unplug_aux_dev+0x1a/0x40 [ice]
      [20976.472313]  ice_lag_event_handler+0x2a2/0x520 [ice]
      [20976.477288]  notifier_call_chain+0x47/0x70
      [20976.481386]  __netdev_upper_dev_link+0x18b/0x280
      [20976.489845]  bond_enslave+0xe05/0x1790 [bonding]
      [20976.494475]  do_setlink+0x336/0xf50
      [20976.502517]  __rtnl_newlink+0x529/0x8b0
      [20976.543441]  rtnl_newlink+0x43/0x60
      [20976.546934]  rtnetlink_rcv_msg+0x2b1/0x360
      [20976.559238]  netlink_rcv_skb+0x4c/0x120
      [20976.563079]  netlink_unicast+0x196/0x230
      [20976.567005]  netlink_sendmsg+0x204/0x3d0
      [20976.570930]  sock_sendmsg+0x4c/0x50
      [20976.574423]  ____sys_sendmsg+0x1eb/0x250
      [20976.586807]  ___sys_sendmsg+0x7c/0xc0
      [20976.606353]  __sys_sendmsg+0x57/0xa0
      [20976.609930]  do_syscall_64+0x5b/0x1a0
      [20976.613598]  entry_SYSCALL_64_after_hwframe+0x65/0xca
      
      1. Command 'ip link ... set nomaster' causes that ice_plug_aux_dev()
         is called from ice_service_task() context, aux device is created
         and associated device->lock is taken.
      2. Command 'ip link ... set master...' calls ice's notifier under
         RTNL lock and that notifier calls ice_unplug_aux_dev(). That
         function tries to take aux device->lock but this is already taken
         by ice_plug_aux_dev() in step 1
      3. Later ice_plug_aux_dev() tries to take RTNL lock but this is already
         taken in step 2
      4. Dead-lock
      
      The patch fixes this issue by following changes:
      - Bit ICE_FLAG_PLUG_AUX_DEV is kept to be set during ice_plug_aux_dev()
        call in ice_service_task()
      - The bit is checked in ice_clear_rdma_cap() and only if it is not set
        then ice_unplug_aux_dev() is called. If it is set (in other words
        plugging of aux device was requested and ice_plug_aux_dev() is
        potentially running) then the function only clears the bit
      - Once ice_plug_aux_dev() call (in ice_service_task) is finished
        the bit ICE_FLAG_PLUG_AUX_DEV is cleared but it is also checked
        whether it was already cleared by ice_clear_rdma_cap(). If so then
        aux device is unplugged.
      Signed-off-by: default avatarIvan Vecera <ivecera@redhat.com>
      Co-developed-by: default avatarPetr Oros <poros@redhat.com>
      Signed-off-by: default avatarPetr Oros <poros@redhat.com>
      Reviewed-by: default avatarDave Ertman <david.m.ertman@intel.com>
      Link: https://lore.kernel.org/r/20220310171641.3863659-1-ivecera@redhat.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      5cb1ebdb
    • Heiner Kallweit's avatar
      net: phy: meson-gxl: improve link-up behavior · 2c87c6f9
      Heiner Kallweit authored
      Sometimes the link comes up but no data flows. This patch fixes
      this behavior. It's not clear what's the root cause of the issue.
      
      According to the tests one other link-up issue remains.
      In very rare cases the link isn't even reported as up.
      
      Fixes: 84c8f773 ("net: phy: meson-gxl: remove the use of .ack_callback()")
      Tested-by: default avatarErico Nunes <nunes.erico@gmail.com>
      Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
      Link: https://lore.kernel.org/r/e3473452-a1f9-efcf-5fdd-02b6f44c3fcd@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      2c87c6f9