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, 51 insertions, 0 deletions

diff --git a/drivers/dpll/dpll_nl.h b/drivers/dpll/dpll_nl.h
new file mode 100644
index 000000000..fa8280e3d
--- /dev/null
+++ b/drivers/dpll/dpll_nl.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/dpll.yaml */
+/* YNL-GEN kernel header */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#ifndef _LINUX_DPLL_GEN_H
+#define _LINUX_DPLL_GEN_H
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include <uapi/linux/dpll.h>
+
+/* Common nested types */
+extern const struct nla_policy dpll_pin_parent_device_nl_policy[DPLL_A_PIN_OPERSTATE + 1];
+extern const struct nla_policy dpll_pin_parent_pin_nl_policy[DPLL_A_PIN_STATE + 1];
+extern const struct nla_policy dpll_reference_sync_nl_policy[DPLL_A_PIN_STATE + 1];
+
+int dpll_lock_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+		   struct genl_info *info);
+int dpll_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+		  struct genl_info *info);
+int dpll_pin_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+		      struct genl_info *info);
+void
+dpll_unlock_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+		 struct genl_info *info);
+void
+dpll_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+	       struct genl_info *info);
+void
+dpll_pin_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
+		   struct genl_info *info);
+
+int dpll_nl_device_id_get_doit(struct sk_buff *skb, struct genl_info *info);
+int dpll_nl_device_get_doit(struct sk_buff *skb, struct genl_info *info);
+int dpll_nl_device_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int dpll_nl_device_set_doit(struct sk_buff *skb, struct genl_info *info);
+int dpll_nl_pin_id_get_doit(struct sk_buff *skb, struct genl_info *info);
+int dpll_nl_pin_get_doit(struct sk_buff *skb, struct genl_info *info);
+int dpll_nl_pin_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int dpll_nl_pin_set_doit(struct sk_buff *skb, struct genl_info *info);
+
+enum {
+	DPLL_NLGRP_MONITOR,
+};
+
+extern struct genl_family dpll_nl_family;
+
+#endif /* _LINUX_DPLL_GEN_H */