[PATCH net-next v2 0/6] xfrm & bonding: Correct use of xso.real_dev

[Cosmin Ratiu <cratiu@nvidia.com>]

This patch series was motivated by fixing a few bugs in the bonding
driver related to xfrm state migration on device failover.

struct xfrm_dev_offload has two net_device pointers: dev and real_dev.
The first one is the device the xfrm_state is offloaded on and the
second one is used by the bonding driver to manage the underlying device
xfrm_states are actually offloaded on. When bonding isn't used, the two
pointers are the same.

This causes confusion in drivers: Which device pointer should they use?
If they want to support bonding, they need to only use real_dev and
never look at dev.

Furthermore, real_dev is used without proper locking from multiple code
paths and changing it is dangerous. See commit [1] for example.

This patch series clears things out by removing all uses of real_dev
from outside the bonding driver.
Then, the bonding driver is refactored to fix a couple of long standing
races and the original bug which motivated this patch series.

[1] commit f8cde9805981 ("bonding: fix xfrm real_dev null pointer
dereference")

v1 -> v2:
Added missing kdoc for various functions.
Made bond_ipsec_del_sa() use xso.real_dev instead of curr_active_slave.

Cosmin Ratiu (6):
Cleaning up unnecessary uses of xso.real_dev:
  net/mlx5: Avoid using xso.real_dev unnecessarily
  xfrm: Use xdo.dev instead of xdo.real_dev
  xfrm: Remove unneeded device check from validate_xmit_xfrm
Refactoring device operations to get an explicit device pointer:
  xfrm: Add explicit dev to .xdo_dev_state_{add,delete,free}
Fixing a bonding xfrm state migration bug:
  bonding: Mark active offloaded xfrm_states
Fixing long standing races in bonding:
  bonding: Fix multiple long standing offload races

 Documentation/networking/xfrm_device.rst      |  10 +-
 drivers/net/bonding/bond_main.c               | 113 +++++++++---------
 .../net/ethernet/chelsio/cxgb4/cxgb4_main.c   |  20 ++--
 .../inline_crypto/ch_ipsec/chcr_ipsec.c       |  18 ++-
 .../net/ethernet/intel/ixgbe/ixgbe_ipsec.c    |  41 ++++---
 drivers/net/ethernet/intel/ixgbevf/ipsec.c    |  21 ++--
 .../marvell/octeontx2/nic/cn10k_ipsec.c       |  18 +--
 .../mellanox/mlx5/core/en_accel/ipsec.c       |  28 ++---
 .../mellanox/mlx5/core/en_accel/ipsec.h       |   1 +
 .../net/ethernet/netronome/nfp/crypto/ipsec.c |  11 +-
 drivers/net/netdevsim/ipsec.c                 |  15 ++-
 include/linux/netdevice.h                     |  10 +-
 include/net/xfrm.h                            |   8 ++
 net/xfrm/xfrm_device.c                        |  13 +-
 net/xfrm/xfrm_state.c                         |  16 +--
 15 files changed, 182 insertions(+), 161 deletions(-)

-- 
2.45.0