Files
linux/net/ethtool/linkinfo.c
Jakub Kicinski f32fe1d79a net: ethtool: add netif_get_link_ksettings() for correct ops-locked use
__ethtool_get_link_ksettings() is exported and called from sysfs
and many drivers. It invokes ethtool_ops->get_link_ksettings
so by our own docs it should be holding netdev lock for ops locked
devices. Looks like commit 2bcf4772e4 ("net: ethtool:
try to protect all callback with netdev instance lock")
missed adding the ops lock here.

There's a number of callers we need to fix up so let's add the
netif_get_link_ksettings() helper first, without any actual
locking changes (this commit is a nop).

Not treating this as a fix because I don't think any driver cares
at this point, but if we want to remove the rtnl_lock protection
this will become critical.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04 14:04:55 -07:00

146 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include "common.h"
#include "netlink.h"
struct linkinfo_req_info {
struct ethnl_req_info base;
};
struct linkinfo_reply_data {
struct ethnl_reply_data base;
struct ethtool_link_ksettings ksettings;
struct ethtool_link_settings *lsettings;
};
#define LINKINFO_REPDATA(__reply_base) \
container_of(__reply_base, struct linkinfo_reply_data, base)
const struct nla_policy ethnl_linkinfo_get_policy[] = {
[ETHTOOL_A_LINKINFO_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
};
static int linkinfo_prepare_data(const struct ethnl_req_info *req_base,
struct ethnl_reply_data *reply_base,
const struct genl_info *info)
{
struct linkinfo_reply_data *data = LINKINFO_REPDATA(reply_base);
struct net_device *dev = reply_base->dev;
int ret;
data->lsettings = &data->ksettings.base;
ret = ethnl_ops_begin(dev);
if (ret < 0)
return ret;
ret = netif_get_link_ksettings(dev, &data->ksettings);
if (ret < 0)
GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
ethnl_ops_complete(dev);
return ret;
}
static int linkinfo_reply_size(const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
return nla_total_size(sizeof(u8)) /* LINKINFO_PORT */
+ nla_total_size(sizeof(u8)) /* LINKINFO_PHYADDR */
+ nla_total_size(sizeof(u8)) /* LINKINFO_TP_MDIX */
+ nla_total_size(sizeof(u8)) /* LINKINFO_TP_MDIX_CTRL */
+ nla_total_size(sizeof(u8)) /* LINKINFO_TRANSCEIVER */
+ 0;
}
static int linkinfo_fill_reply(struct sk_buff *skb,
const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
const struct linkinfo_reply_data *data = LINKINFO_REPDATA(reply_base);
if (nla_put_u8(skb, ETHTOOL_A_LINKINFO_PORT, data->lsettings->port) ||
nla_put_u8(skb, ETHTOOL_A_LINKINFO_PHYADDR,
data->lsettings->phy_address) ||
nla_put_u8(skb, ETHTOOL_A_LINKINFO_TP_MDIX,
data->lsettings->eth_tp_mdix) ||
nla_put_u8(skb, ETHTOOL_A_LINKINFO_TP_MDIX_CTRL,
data->lsettings->eth_tp_mdix_ctrl) ||
nla_put_u8(skb, ETHTOOL_A_LINKINFO_TRANSCEIVER,
data->lsettings->transceiver))
return -EMSGSIZE;
return 0;
}
/* LINKINFO_SET */
const struct nla_policy ethnl_linkinfo_set_policy[] = {
[ETHTOOL_A_LINKINFO_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
[ETHTOOL_A_LINKINFO_PORT] = { .type = NLA_U8 },
[ETHTOOL_A_LINKINFO_PHYADDR] = { .type = NLA_U8 },
[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL] = { .type = NLA_U8 },
};
static int
ethnl_set_linkinfo_validate(struct ethnl_req_info *req_info,
struct genl_info *info)
{
const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
if (!ops->get_link_ksettings || !ops->set_link_ksettings)
return -EOPNOTSUPP;
return 1;
}
static int
ethnl_set_linkinfo(struct ethnl_req_info *req_info, struct genl_info *info)
{
struct ethtool_link_ksettings ksettings = {};
struct ethtool_link_settings *lsettings;
struct net_device *dev = req_info->dev;
struct nlattr **tb = info->attrs;
bool mod = false;
int ret;
ret = netif_get_link_ksettings(dev, &ksettings);
if (ret < 0) {
GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
return ret;
}
lsettings = &ksettings.base;
ethnl_update_u8(&lsettings->port, tb[ETHTOOL_A_LINKINFO_PORT], &mod);
ethnl_update_u8(&lsettings->phy_address, tb[ETHTOOL_A_LINKINFO_PHYADDR],
&mod);
ethnl_update_u8(&lsettings->eth_tp_mdix_ctrl,
tb[ETHTOOL_A_LINKINFO_TP_MDIX_CTRL], &mod);
if (!mod)
return 0;
ret = dev->ethtool_ops->set_link_ksettings(dev, &ksettings);
if (ret < 0) {
GENL_SET_ERR_MSG(info, "link settings update failed");
return ret;
}
return 1;
}
const struct ethnl_request_ops ethnl_linkinfo_request_ops = {
.request_cmd = ETHTOOL_MSG_LINKINFO_GET,
.reply_cmd = ETHTOOL_MSG_LINKINFO_GET_REPLY,
.hdr_attr = ETHTOOL_A_LINKINFO_HEADER,
.req_info_size = sizeof(struct linkinfo_req_info),
.reply_data_size = sizeof(struct linkinfo_reply_data),
.prepare_data = linkinfo_prepare_data,
.reply_size = linkinfo_reply_size,
.fill_reply = linkinfo_fill_reply,
.set_validate = ethnl_set_linkinfo_validate,
.set = ethnl_set_linkinfo,
.set_ntf_cmd = ETHTOOL_MSG_LINKINFO_NTF,
};