Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Petr Machata
authored
[ Upstream commit 62bef63646c194e0f82b40304a0f2d060b28687b ]
If there are IPIP nexthops at the time when the driver is loaded (or the
devlink instance reloaded), the driver looks up the corresponding IPIP
entry. But IPIP entries are only created as a result of netdevice
notifications. Since the netdevice notifier is registered after the nexthop
notifier, mlxsw_sp_nexthop_type_init() never finds the IPIP entry,
registers the nexthop MLXSW_SP_NEXTHOP_TYPE_ETH, and fails to assign a CRIF
to the nexthop. Later on when the CRIF is necessary, the WARN_ON in
mlxsw_sp_nexthop_rif() triggers, causing the splat [1].
In order to fix the issue, reorder the netdevice notifier to be registered
before the nexthop one.
[1] (edited for clarity):
WARNING: CPU: 1 PID: 1364 at drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3245 mlxsw_sp_nexthop_rif (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3246 (discriminator 1)) mlxsw_spectrum
Hardware name: Mellanox Technologies Ltd. MSN4410/VMOD0010, BIOS 5.11 01/06/2019
Call Trace:
? mlxsw_sp_nexthop_rif (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3246 (discriminator 1)) mlxsw_spectrum
__mlxsw_sp_nexthop_eth_update (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3637) mlxsw_spectrum
mlxsw_sp_nexthop_update (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3679 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3727) mlxsw_spectrum
mlxsw_sp_nexthop_group_update (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3757) mlxsw_spectrum
mlxsw_sp_nexthop_group_refresh (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:4112) mlxsw_spectrum
mlxsw_sp_nexthop_obj_event (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5118 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5191 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5315 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5500) mlxsw_spectrum
nexthops_dump (net/ipv4/nexthop.c:217 net/ipv4/nexthop.c:440 net/ipv4/nexthop.c:3609)
register_nexthop_notifier (net/ipv4/nexthop.c:3624)
mlxsw_sp_router_init (drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:11486) mlxsw_spectrum
mlxsw_sp_init (drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3267) mlxsw_spectrum
__mlxsw_core_bus_device_register (drivers/net/ethernet/mellanox/mlxsw/core.c:2202) mlxsw_core
mlxsw_devlink_core_bus_device_reload_up (drivers/net/ethernet/mellanox/mlxsw/core.c:2265 drivers/net/ethernet/mellanox/mlxsw/core.c:1603) mlxsw_core
devlink_reload (net/devlink/dev.c:314 net/devlink/dev.c:475)
[...]
Fixes: 9464a3d6 ("mlxsw: spectrum_router: Track next hops at CRIFs")
Reported-by: 
Maksym Yaremchuk <maksymy@nvidia.com>
Signed-off-by: 
Petr Machata <petrm@nvidia.com>
Reviewed-by: 
Ido Schimmel <idosch@nvidia.com>
Acked-by: 
Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/74edb8d45d004e8d8f5318eede6ccc3d786d8ba9.1705502064.git.petrm@nvidia.com
Signed-off-by: 
Jakub Kicinski <kuba@kernel.org>
Signed-off-by: 
Sasha Levin <sashal@kernel.org>