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, 281 insertions, 0 deletions

diff --git a/net/ethtool/tunnels.c b/net/ethtool/tunnels.c
new file mode 100644
index 000000000..b4ce47dd2
--- /dev/null
+++ b/net/ethtool/tunnels.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ethtool_netlink.h>
+#include <net/udp_tunnel.h>
+#include <net/vxlan.h>
+
+#include "bitset.h"
+#include "common.h"
+#include "netlink.h"
+
+const struct nla_policy ethnl_tunnel_info_get_policy[] = {
+	[ETHTOOL_A_TUNNEL_INFO_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN == ilog2(UDP_TUNNEL_TYPE_VXLAN));
+static_assert(ETHTOOL_UDP_TUNNEL_TYPE_GENEVE == ilog2(UDP_TUNNEL_TYPE_GENEVE));
+static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE ==
+	      ilog2(UDP_TUNNEL_TYPE_VXLAN_GPE));
+
+static ssize_t ethnl_udp_table_reply_size(unsigned int types, bool compact)
+{
+	ssize_t size;
+
+	size = ethnl_bitset32_size(&types, NULL, __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
+				   udp_tunnel_type_names, compact);
+	if (size < 0)
+		return size;
+
+	return size +
+		nla_total_size(0) + /* _UDP_TABLE */
+		nla_total_size(sizeof(u32)); /* _UDP_TABLE_SIZE */
+}
+
+static ssize_t
+ethnl_tunnel_info_reply_size(const struct ethnl_req_info *req_base,
+			     struct netlink_ext_ack *extack)
+{
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct udp_tunnel_nic_info *info;
+	unsigned int i;
+	ssize_t ret;
+	size_t size;
+
+	info = req_base->dev->udp_tunnel_nic_info;
+	if (!info) {
+		NL_SET_ERR_MSG(extack,
+			       "device does not report tunnel offload info");
+		return -EOPNOTSUPP;
+	}
+
+	size =	nla_total_size(0); /* _INFO_UDP_PORTS */
+
+	for (i = 0; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
+		if (!info->tables[i].n_entries)
+			break;
+
+		ret = ethnl_udp_table_reply_size(info->tables[i].tunnel_types,
+						 compact);
+		if (ret < 0)
+			return ret;
+		size += ret;
+
+		size += udp_tunnel_nic_dump_size(req_base->dev, i);
+	}
+
+	if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN) {
+		ret = ethnl_udp_table_reply_size(0, compact);
+		if (ret < 0)
+			return ret;
+		size += ret;
+
+		size += nla_total_size(0) +		 /* _TABLE_ENTRY */
+			nla_total_size(sizeof(__be16)) + /* _ENTRY_PORT */
+			nla_total_size(sizeof(u32));	 /* _ENTRY_TYPE */
+	}
+
+	return size;
+}
+
+static int
+ethnl_tunnel_info_fill_reply(const struct ethnl_req_info *req_base,
+			     struct sk_buff *skb)
+{
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct udp_tunnel_nic_info *info;
+	struct nlattr *ports, *table, *entry;
+	unsigned int i;
+
+	info = req_base->dev->udp_tunnel_nic_info;
+	if (!info)
+		return -EOPNOTSUPP;
+
+	ports = nla_nest_start(skb, ETHTOOL_A_TUNNEL_INFO_UDP_PORTS);
+	if (!ports)
+		return -EMSGSIZE;
+
+	for (i = 0; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
+		if (!info->tables[i].n_entries)
+			break;
+
+		table = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE);
+		if (!table)
+			goto err_cancel_ports;
+
+		if (nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE,
+				info->tables[i].n_entries))
+			goto err_cancel_table;
+
+		if (ethnl_put_bitset32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES,
+				       &info->tables[i].tunnel_types, NULL,
+				       __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
+				       udp_tunnel_type_names, compact))
+			goto err_cancel_table;
+
+		if (udp_tunnel_nic_dump_write(req_base->dev, i, skb))
+			goto err_cancel_table;
+
+		nla_nest_end(skb, table);
+	}
+
+	if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN) {
+		u32 zero = 0;
+
+		table = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE);
+		if (!table)
+			goto err_cancel_ports;
+
+		if (nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE, 1))
+			goto err_cancel_table;
+
+		if (ethnl_put_bitset32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES,
+				       &zero, NULL,
+				       __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
+				       udp_tunnel_type_names, compact))
+			goto err_cancel_table;
+
+		entry = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY);
+		if (!entry)
+			goto err_cancel_entry;
+
+		if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,
+				 htons(IANA_VXLAN_UDP_PORT)) ||
+		    nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE,
+				ilog2(UDP_TUNNEL_TYPE_VXLAN)))
+			goto err_cancel_entry;
+
+		nla_nest_end(skb, entry);
+		nla_nest_end(skb, table);
+	}
+
+	nla_nest_end(skb, ports);
+
+	return 0;
+
+err_cancel_entry:
+	nla_nest_cancel(skb, entry);
+err_cancel_table:
+	nla_nest_cancel(skb, table);
+err_cancel_ports:
+	nla_nest_cancel(skb, ports);
+	return -EMSGSIZE;
+}
+
+int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct ethnl_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
+	struct sk_buff *rskb;
+	void *reply_payload;
+	int reply_len;
+	int ret;
+
+	ret = ethnl_parse_header_dev_get(&req_info,
+					 tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	rtnl_lock();
+	ret = ethnl_tunnel_info_reply_size(&req_info, info->extack);
+	if (ret < 0)
+		goto err_unlock_rtnl;
+	reply_len = ret + ethnl_reply_header_size();
+
+	rskb = ethnl_reply_init(reply_len, req_info.dev,
+				ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
+				ETHTOOL_A_TUNNEL_INFO_HEADER,
+				info, &reply_payload);
+	if (!rskb) {
+		ret = -ENOMEM;
+		goto err_unlock_rtnl;
+	}
+
+	ret = ethnl_tunnel_info_fill_reply(&req_info, rskb);
+	if (ret)
+		goto err_free_msg;
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info);
+	genlmsg_end(rskb, reply_payload);
+
+	return genlmsg_reply(rskb, info);
+
+err_free_msg:
+	nlmsg_free(rskb);
+err_unlock_rtnl:
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info);
+	return ret;
+}
+
+struct ethnl_tunnel_info_dump_ctx {
+	struct ethnl_req_info	req_info;
+	unsigned long		ifindex;
+};
+
+int ethnl_tunnel_info_start(struct netlink_callback *cb)
+{
+	const struct genl_dumpit_info *info = genl_dumpit_info(cb);
+	struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
+	struct nlattr **tb = info->info.attrs;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	memset(ctx, 0, sizeof(*ctx));
+
+	ret = ethnl_parse_header_dev_get(&ctx->req_info,
+					 tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
+					 sock_net(cb->skb->sk), cb->extack,
+					 false);
+	if (ctx->req_info.dev) {
+		ethnl_parse_header_dev_put(&ctx->req_info);
+		ctx->req_info.dev = NULL;
+	}
+
+	return ret;
+}
+
+int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
+	struct net *net = sock_net(skb->sk);
+	struct net_device *dev;
+	int ret = 0;
+	void *ehdr;
+
+	rtnl_lock();
+	for_each_netdev_dump(net, dev, ctx->ifindex) {
+		ehdr = ethnl_dump_put(skb, cb,
+				      ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY);
+		if (!ehdr) {
+			ret = -EMSGSIZE;
+			break;
+		}
+
+		ret = ethnl_fill_reply_header(skb, dev,
+					      ETHTOOL_A_TUNNEL_INFO_HEADER);
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			break;
+		}
+
+		ctx->req_info.dev = dev;
+		ret = ethnl_tunnel_info_fill_reply(&ctx->req_info, skb);
+		ctx->req_info.dev = NULL;
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			if (ret == -EOPNOTSUPP)
+				continue;
+			break;
+		}
+		genlmsg_end(skb, ehdr);
+	}
+	rtnl_unlock();
+
+	if (ret == -EMSGSIZE && skb->len)
+		return skb->len;
+	return ret;
+}