From 5c6201319ca7491d4315c36b9d15d399c5158c6c Mon Sep 17 00:00:00 2001 From: Alaa Hleihel Date: Tue, 12 May 2020 10:54:21 -0400 Subject: [PATCH 154/312] [netdrv] net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa Message-id: <20200512105530.4207-56-ahleihel@redhat.com> Patchwork-id: 306927 Patchwork-instance: patchwork O-Subject: [RHEL8.3 BZ 1789382 055/124] net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa Bugzilla: 1789382 RH-Acked-by: Tony Camuso RH-Acked-by: Kamal Heib RH-Acked-by: Jarod Wilson Bugzilla: http://bugzilla.redhat.com/1789382 Upstream: v5.6-rc3 commit 3d9c5e023a0dbf3e117bb416cfefd9405bf5af0c Author: Huy Nguyen Date: Mon Feb 3 16:32:18 2020 -0600 net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa 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 Even if a user does it, so he will read a value which is no longer valid.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: 8da202b24913 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.") Signed-off-by: Huy Nguyen Reviewed-by: Mark Bloch Signed-off-by: Saeed Mahameed Signed-off-by: Alaa Hleihel Signed-off-by: Frantisek Hrbata --- drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c index 8e53bc0a6b6e..2151787235e0 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c @@ -2456,25 +2456,17 @@ int mlx5_eswitch_set_vepa(struct mlx5_eswitch *esw, u8 setting) 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, -- 2.13.6