From: Jakub Kicinski Date: Wed, 24 Jun 2026 19:04:39 +0000 (-0700) Subject: net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link() X-Git-Tag: v7.2-rc1~29^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1105ef941c1a28e115d1b97f17e1c85576884100;p=thirdparty%2Flinux.git net: ethtool: keep rtnl_lock for ops using ethtool_op_get_link() Breno reports following splats on mlx5: RTNL: assertion failed at net/core/dev.c (2241) WARNING: net/core/dev.c:2241 at netif_state_change+0xed/0x130, CPU#5: ethtool/1335 RIP: 0010:netif_state_change+0xf9/0x130 Call Trace: __linkwatch_sync_dev+0xea/0x120 ethtool_op_get_link+0xe/0x20 __ethtool_get_link+0x26/0x40 linkstate_prepare_data+0x51/0x200 ethnl_default_doit+0x213/0x470 genl_family_rcv_msg_doit+0xdd/0x110 Looks like I missed ethtool_op_get_link() trying to sync linkwatch, which needs rtnl_lock. Not all drivers do this - bnxt doesn't, it just returns the link state, so add an opt-in bit. Reported-by: Breno Leitao Fixes: 45079e00133e ("net: ethtool: optionally skip rtnl_lock on Netlink path for GET ops") Acked-by: Stanislav Fomichev Reviewed-by: Breno Leitao Acked-by: Harshitha Ramamurthy Link: https://patch.msgid.link/20260624190439.2521219-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c index 7cc22916852fb..8199738ba979e 100644 --- a/drivers/net/ethernet/google/gve/gve_ethtool.c +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c @@ -984,7 +984,8 @@ const struct ethtool_ops gve_ethtool_ops = { .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT | ETHTOOL_RING_USE_RX_BUF_LEN, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | - ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = gve_get_drvinfo, .get_strings = gve_get_strings, .get_sset_count = gve_get_sset_count, diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c index a615d599b88ee..e7cf12eaa2689 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c +++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c @@ -1855,6 +1855,7 @@ static const struct ethtool_ops iavf_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE, .supported_input_xfrm = RXH_XFRM_SYM_XOR, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = iavf_get_drvinfo, .get_link = ethtool_op_get_link, .get_ringparam = iavf_get_ringparam, diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c index 2f5b626ba33fe..112926d07634d 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c @@ -2721,7 +2721,8 @@ const struct ethtool_ops mlx5e_ethtool_ops = { .rxfh_max_num_contexts = MLX5E_MAX_NUM_RSS, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | - ETHTOOL_OP_NEEDS_RTNL_SPFLAGS, + ETHTOOL_OP_NEEDS_RTNL_SPFLAGS | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE | diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c index 1a8a19f980d33..c8b76d301c92c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c @@ -419,7 +419,8 @@ static const struct ethtool_ops mlx5e_rep_ethtool_ops = { ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | - ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = mlx5e_rep_get_drvinfo, .get_link = ethtool_op_get_link, .get_strings = mlx5e_rep_get_strings, diff --git a/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c index 9b3b32408c64b..01ddc3def9ac0 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c @@ -286,7 +286,8 @@ const struct ethtool_ops mlx5i_ethtool_ops = { ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | - ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = mlx5i_get_drvinfo, .get_strings = mlx5i_get_strings, .get_sset_count = mlx5i_get_sset_count, @@ -309,6 +310,7 @@ const struct ethtool_ops mlx5i_ethtool_ops = { }; const struct ethtool_ops mlx5i_pkey_ethtool_ops = { + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = mlx5i_get_drvinfo, .get_link = ethtool_op_get_link, .get_ts_info = mlx5i_get_ts_info, diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c index cb34fc166ef96..0e47088ec44ba 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c @@ -2024,7 +2024,8 @@ static const struct ethtool_ops fbnic_ethtool_ops = { ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM | ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM | ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | - ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_drvinfo = fbnic_get_drvinfo, .get_regs_len = fbnic_get_regs_len, .get_regs = fbnic_get_regs, diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index 94e658d07a27e..881df597d7f9c 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -597,7 +597,8 @@ static int mana_get_link_ksettings(struct net_device *ndev, const struct ethtool_ops mana_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_RX_CQE_FRAMES, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | - ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_GLINK, .get_ethtool_stats = mana_get_ethtool_stats, .get_sset_count = mana_get_sset_count, .get_strings = mana_get_strings, diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 1b834e2a522ec..5d491a98265ef 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -942,6 +942,7 @@ struct kernel_ethtool_ts_info { #define ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM BIT(5) #define ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM BIT(6) #define ETHTOOL_OP_NEEDS_RTNL_RSS BIT(7) +#define ETHTOOL_OP_NEEDS_RTNL_GLINK BIT(8) /** * struct ethtool_ops - optional netdev operations @@ -978,6 +979,7 @@ struct kernel_ethtool_ts_info { * - phylink helpers (note that phydev is currently unsupported!) * - netdev_update_features() * - netif_set_real_num_tx_queues() + * - ethtool_op_get_link() (syncs link watch under rtnl_lock) * * @get_drvinfo: Report driver/device information. Modern drivers no * longer have to implement this callback. Most fields are diff --git a/net/ethtool/common.h b/net/ethtool/common.h index 2b3847f008018..4e5356e26f400 100644 --- a/net/ethtool/common.h +++ b/net/ethtool/common.h @@ -113,6 +113,8 @@ ethtool_nl_msg_needs_rtnl(const struct net_device *dev, u8 cmd) return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM; case ETHTOOL_MSG_RSS_SET: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_RSS; + case ETHTOOL_MSG_LINKSTATE_GET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_GLINK; case ETHTOOL_MSG_TSCONFIG_GET: case ETHTOOL_MSG_TSCONFIG_SET: /* tsconfig calls ndos (ndo_hwtstamp_set/get), not ethtool ops. @@ -159,6 +161,8 @@ ethtool_ioctl_needs_rtnl(const struct net_device *dev, u32 ethcmd) case ETHTOOL_SRXFH: case ETHTOOL_SRXFHINDIR: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_RSS; + case ETHTOOL_GLINK: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_GLINK; } return false; }