ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 383 insertions, 0 deletions

diff --git a/net/ethtool/pse-pd.c b/net/ethtool/pse-pd.c
new file mode 100644
index 000000000..757c9e0cc
--- /dev/null
+++ b/net/ethtool/pse-pd.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// ethtool interface for Ethernet PSE (Power Sourcing Equipment)
+// and PD (Powered Device)
+//
+// Copyright (c) 2022 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+//
+
+#include <linux/ethtool_netlink.h>
+#include <linux/ethtool.h>
+#include <linux/export.h>
+#include <linux/phy.h>
+
+#include "common.h"
+#include "linux/pse-pd/pse.h"
+#include "netlink.h"
+
+struct pse_req_info {
+	struct ethnl_req_info base;
+};
+
+struct pse_reply_data {
+	struct ethnl_reply_data	base;
+	struct ethtool_pse_control_status status;
+};
+
+#define PSE_REPDATA(__reply_base) \
+	container_of(__reply_base, struct pse_reply_data, base)
+
+/* PSE_GET */
+
+const struct nla_policy ethnl_pse_get_policy[ETHTOOL_A_PSE_HEADER + 1] = {
+	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy_phy),
+};
+
+static int pse_get_pse_attributes(struct phy_device *phydev,
+				  struct netlink_ext_ack *extack,
+				  struct pse_reply_data *data)
+{
+	if (!phydev) {
+		NL_SET_ERR_MSG(extack, "No PHY found");
+		return -EOPNOTSUPP;
+	}
+
+	if (!phydev->psec) {
+		NL_SET_ERR_MSG(extack, "No PSE is attached");
+		return -EOPNOTSUPP;
+	}
+
+	memset(&data->status, 0, sizeof(data->status));
+
+	return pse_ethtool_get_status(phydev->psec, extack, &data->status);
+}
+
+static int pse_prepare_data(const struct ethnl_req_info *req_base,
+			    struct ethnl_reply_data *reply_base,
+			    const struct genl_info *info)
+{
+	struct pse_reply_data *data = PSE_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	struct nlattr **tb = info->attrs;
+	struct phy_device *phydev;
+	int ret;
+
+	phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PSE_HEADER,
+				      info->extack);
+	if (IS_ERR(phydev))
+		return PTR_ERR(phydev);
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = pse_get_pse_attributes(phydev, info->extack, data);
+
+	ethnl_ops_complete(dev);
+
+	return ret;
+}
+
+static int pse_reply_size(const struct ethnl_req_info *req_base,
+			  const struct ethnl_reply_data *reply_base)
+{
+	const struct pse_reply_data *data = PSE_REPDATA(reply_base);
+	const struct ethtool_pse_control_status *st = &data->status;
+	int len = 0;
+
+	if (st->pw_d_id)
+		len += nla_total_size(sizeof(u32)); /* _PSE_PW_D_ID */
+	if (st->podl_admin_state > 0)
+		len += nla_total_size(sizeof(u32)); /* _PODL_PSE_ADMIN_STATE */
+	if (st->podl_pw_status > 0)
+		len += nla_total_size(sizeof(u32)); /* _PODL_PSE_PW_D_STATUS */
+	if (st->c33_admin_state > 0)
+		len += nla_total_size(sizeof(u32)); /* _C33_PSE_ADMIN_STATE */
+	if (st->c33_pw_status > 0)
+		len += nla_total_size(sizeof(u32)); /* _C33_PSE_PW_D_STATUS */
+	if (st->c33_pw_class > 0)
+		len += nla_total_size(sizeof(u32)); /* _C33_PSE_PW_CLASS */
+	if (st->c33_actual_pw > 0)
+		len += nla_total_size(sizeof(u32)); /* _C33_PSE_ACTUAL_PW */
+	if (st->c33_ext_state_info.c33_pse_ext_state > 0) {
+		len += nla_total_size(sizeof(u32)); /* _C33_PSE_EXT_STATE */
+		if (st->c33_ext_state_info.__c33_pse_ext_substate > 0)
+			/* _C33_PSE_EXT_SUBSTATE */
+			len += nla_total_size(sizeof(u32));
+	}
+	if (st->c33_avail_pw_limit > 0)
+		/* _C33_AVAIL_PSE_PW_LIMIT */
+		len += nla_total_size(sizeof(u32));
+	if (st->c33_pw_limit_nb_ranges > 0)
+		/* _C33_PSE_PW_LIMIT_RANGES */
+		len += st->c33_pw_limit_nb_ranges *
+		       (nla_total_size(0) +
+			nla_total_size(sizeof(u32)) * 2);
+	if (st->prio_max)
+		/* _PSE_PRIO_MAX + _PSE_PRIO */
+		len += nla_total_size(sizeof(u32)) * 2;
+
+	return len;
+}
+
+static int pse_put_pw_limit_ranges(struct sk_buff *skb,
+				   const struct ethtool_pse_control_status *st)
+{
+	const struct ethtool_c33_pse_pw_limit_range *pw_limit_ranges;
+	int i;
+
+	pw_limit_ranges = st->c33_pw_limit_ranges;
+	for (i = 0; i < st->c33_pw_limit_nb_ranges; i++) {
+		struct nlattr *nest;
+
+		nest = nla_nest_start(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_RANGES);
+		if (!nest)
+			return -EMSGSIZE;
+
+		if (nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_MIN,
+				pw_limit_ranges->min) ||
+		    nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_MAX,
+				pw_limit_ranges->max)) {
+			nla_nest_cancel(skb, nest);
+			return -EMSGSIZE;
+		}
+		nla_nest_end(skb, nest);
+		pw_limit_ranges++;
+	}
+
+	return 0;
+}
+
+static int pse_fill_reply(struct sk_buff *skb,
+			  const struct ethnl_req_info *req_base,
+			  const struct ethnl_reply_data *reply_base)
+{
+	const struct pse_reply_data *data = PSE_REPDATA(reply_base);
+	const struct ethtool_pse_control_status *st = &data->status;
+
+	if (st->pw_d_id &&
+	    nla_put_u32(skb, ETHTOOL_A_PSE_PW_D_ID,
+			st->pw_d_id))
+		return -EMSGSIZE;
+
+	if (st->podl_admin_state > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_PODL_PSE_ADMIN_STATE,
+			st->podl_admin_state))
+		return -EMSGSIZE;
+
+	if (st->podl_pw_status > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_PODL_PSE_PW_D_STATUS,
+			st->podl_pw_status))
+		return -EMSGSIZE;
+
+	if (st->c33_admin_state > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_C33_PSE_ADMIN_STATE,
+			st->c33_admin_state))
+		return -EMSGSIZE;
+
+	if (st->c33_pw_status > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_D_STATUS,
+			st->c33_pw_status))
+		return -EMSGSIZE;
+
+	if (st->c33_pw_class > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_CLASS,
+			st->c33_pw_class))
+		return -EMSGSIZE;
+
+	if (st->c33_actual_pw > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_C33_PSE_ACTUAL_PW,
+			st->c33_actual_pw))
+		return -EMSGSIZE;
+
+	if (st->c33_ext_state_info.c33_pse_ext_state > 0) {
+		if (nla_put_u32(skb, ETHTOOL_A_C33_PSE_EXT_STATE,
+				st->c33_ext_state_info.c33_pse_ext_state))
+			return -EMSGSIZE;
+
+		if (st->c33_ext_state_info.__c33_pse_ext_substate > 0 &&
+		    nla_put_u32(skb, ETHTOOL_A_C33_PSE_EXT_SUBSTATE,
+				st->c33_ext_state_info.__c33_pse_ext_substate))
+			return -EMSGSIZE;
+	}
+
+	if (st->c33_avail_pw_limit > 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT,
+			st->c33_avail_pw_limit))
+		return -EMSGSIZE;
+
+	if (st->c33_pw_limit_nb_ranges > 0 &&
+	    pse_put_pw_limit_ranges(skb, st))
+		return -EMSGSIZE;
+
+	if (st->prio_max &&
+	    (nla_put_u32(skb, ETHTOOL_A_PSE_PRIO_MAX, st->prio_max) ||
+	     nla_put_u32(skb, ETHTOOL_A_PSE_PRIO, st->prio)))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static void pse_cleanup_data(struct ethnl_reply_data *reply_base)
+{
+	const struct pse_reply_data *data = PSE_REPDATA(reply_base);
+
+	kfree(data->status.c33_pw_limit_ranges);
+}
+
+/* PSE_SET */
+
+const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1] = {
+	[ETHTOOL_A_PSE_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy_phy),
+	[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL] =
+		NLA_POLICY_RANGE(NLA_U32, ETHTOOL_PODL_PSE_ADMIN_STATE_DISABLED,
+				 ETHTOOL_PODL_PSE_ADMIN_STATE_ENABLED),
+	[ETHTOOL_A_C33_PSE_ADMIN_CONTROL] =
+		NLA_POLICY_RANGE(NLA_U32, ETHTOOL_C33_PSE_ADMIN_STATE_DISABLED,
+				 ETHTOOL_C33_PSE_ADMIN_STATE_ENABLED),
+	[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT] = { .type = NLA_U32 },
+	[ETHTOOL_A_PSE_PRIO] = { .type = NLA_U32 },
+};
+
+static int
+ethnl_set_pse_validate(struct phy_device *phydev, struct genl_info *info)
+{
+	struct nlattr **tb = info->attrs;
+
+	if (IS_ERR_OR_NULL(phydev)) {
+		NL_SET_ERR_MSG(info->extack, "No PHY is attached");
+		return -EOPNOTSUPP;
+	}
+
+	if (!phydev->psec) {
+		NL_SET_ERR_MSG(info->extack, "No PSE is attached");
+		return -EOPNOTSUPP;
+	}
+
+	if (tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL] &&
+	    !pse_has_podl(phydev->psec)) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL],
+				    "setting PoDL PSE admin control not supported");
+		return -EOPNOTSUPP;
+	}
+	if (tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL] &&
+	    !pse_has_c33(phydev->psec)) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL],
+				    "setting C33 PSE admin control not supported");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct nlattr **tb = info->attrs;
+	struct phy_device *phydev;
+	int ret;
+
+	phydev = ethnl_req_get_phydev(req_info, tb, ETHTOOL_A_PSE_HEADER,
+				      info->extack);
+	ret = ethnl_set_pse_validate(phydev, info);
+	if (ret)
+		return ret;
+
+	if (tb[ETHTOOL_A_PSE_PRIO]) {
+		unsigned int prio;
+
+		prio = nla_get_u32(tb[ETHTOOL_A_PSE_PRIO]);
+		ret = pse_ethtool_set_prio(phydev->psec, info->extack, prio);
+		if (ret)
+			return ret;
+	}
+
+	if (tb[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT]) {
+		unsigned int pw_limit;
+
+		pw_limit = nla_get_u32(tb[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT]);
+		ret = pse_ethtool_set_pw_limit(phydev->psec, info->extack,
+					       pw_limit);
+		if (ret)
+			return ret;
+	}
+
+	/* These values are already validated by the ethnl_pse_set_policy */
+	if (tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL] ||
+	    tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL]) {
+		struct pse_control_config config = {};
+
+		if (tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL])
+			config.podl_admin_control = nla_get_u32(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);
+		if (tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL])
+			config.c33_admin_control = nla_get_u32(tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL]);
+
+		/* pse_ethtool_set_config() will do nothing if the config
+		 * is zero
+		 */
+		ret = pse_ethtool_set_config(phydev->psec, info->extack,
+					     &config);
+		if (ret)
+			return ret;
+	}
+
+	/* Return errno or zero - PSE has no notification */
+	return ret;
+}
+
+const struct ethnl_request_ops ethnl_pse_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PSE_GET,
+	.reply_cmd		= ETHTOOL_MSG_PSE_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_PSE_HEADER,
+	.req_info_size		= sizeof(struct pse_req_info),
+	.reply_data_size	= sizeof(struct pse_reply_data),
+
+	.prepare_data		= pse_prepare_data,
+	.reply_size		= pse_reply_size,
+	.fill_reply		= pse_fill_reply,
+	.cleanup_data		= pse_cleanup_data,
+
+	.set			= ethnl_set_pse,
+	/* PSE has no notification */
+};
+
+void ethnl_pse_send_ntf(struct net_device *netdev, unsigned long notifs)
+{
+	void *reply_payload;
+	struct sk_buff *skb;
+	int reply_len;
+	int ret;
+
+	ASSERT_RTNL();
+
+	if (!netdev || !notifs)
+		return;
+
+	reply_len = ethnl_reply_header_size() +
+		    nla_total_size(sizeof(u32)); /* _PSE_NTF_EVENTS */
+
+	skb = genlmsg_new(reply_len, GFP_KERNEL);
+	if (!skb)
+		return;
+
+	reply_payload = ethnl_bcastmsg_put(skb, ETHTOOL_MSG_PSE_NTF);
+	if (!reply_payload)
+		goto err_skb;
+
+	ret = ethnl_fill_reply_header(skb, netdev, ETHTOOL_A_PSE_NTF_HEADER);
+	if (ret < 0)
+		goto err_skb;
+
+	if (nla_put_uint(skb, ETHTOOL_A_PSE_NTF_EVENTS, notifs))
+		goto err_skb;
+
+	genlmsg_end(skb, reply_payload);
+	ethnl_multicast(skb, netdev);
+	return;
+
+err_skb:
+	nlmsg_free(skb);
+}
+EXPORT_SYMBOL_GPL(ethnl_pse_send_ntf);