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:
    <TASK>
     __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 <leitao@debian.org>
Fixes: 45079e0013 ("net: ethtool: optionally skip rtnl_lock on Netlink path for GET ops")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Breno Leitao <leitao@debian.org>
Acked-by: Harshitha Ramamurthy <hramamurthy@google.com>
Link: https://patch.msgid.link/20260624190439.2521219-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2026-06-24 12:04:39 -07:00
parent 2c0f1b651d
commit 1105ef941c
9 changed files with 20 additions and 6 deletions

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@ -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,

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@ -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,

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@ -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 |

View File

@ -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,

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@ -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,

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@ -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,

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@ -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,

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@ -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

View File

@ -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;
}