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net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa 

commit 3d9c5e023a upstream.

rtnl_bridge_getlink is protected by rcu lock, so mlx5_eswitch_get_vepa
cannot take mutex lock. Two possible issues can happen:
1. User at the same time change vepa mode via RTM_SETLINK command.
2. User at the same time change the switchdev mode via devlink netlink
interface.

Case 1 cannot happen because rtnl executes one message in order.
Case 2 can happen but we do not expect user to change the switchdev mode
when changing vepa. Even if a user does it, so he will read a value
which is no longer valid.

Fixes: 8da202b249 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Huy Nguyen 2020-02-03 16:32:18 -06:00 committed by Greg Kroah-Hartman
parent 06320052ee
commit fca1cdd341
1 changed files with 3 additions and 11 deletions
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14
drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
View File

@ -2319,25 +2319,17 @@ out:
int mlx5_eswitch_get_vepa(struct mlx5_eswitch *esw, u8 *setting)
{
int err = 0;
if (!esw)
return -EOPNOTSUPP;
if (!ESW_ALLOWED(esw))
return -EPERM;
mutex_lock(&esw->state_lock);
if (esw->mode != MLX5_ESWITCH_LEGACY) {
err = -EOPNOTSUPP;
goto out;
}
if (esw->mode != MLX5_ESWITCH_LEGACY)
return -EOPNOTSUPP;
*setting = esw->fdb_table.legacy.vepa_uplink_rule ? 1 : 0;
out:
mutex_unlock(&esw->state_lock);
return err;
return 0;
}
int mlx5_eswitch_set_vport_trust(struct mlx5_eswitch *esw,