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, 148 insertions, 0 deletions

diff --git a/net/batman-adv/log.h b/net/batman-adv/log.h
new file mode 100644
index 000000000..9f3aed826
--- /dev/null
+++ b/net/batman-adv/log.h
@@ -0,0 +1,148 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner, Simon Wunderlich
+ */
+
+#ifndef _NET_BATMAN_ADV_LOG_H_
+#define _NET_BATMAN_ADV_LOG_H_
+
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/printk.h>
+
+#ifdef CONFIG_BATMAN_ADV_DEBUG
+
+int batadv_debug_log_setup(struct batadv_priv *bat_priv);
+void batadv_debug_log_cleanup(struct batadv_priv *bat_priv);
+
+#else
+
+static inline int batadv_debug_log_setup(struct batadv_priv *bat_priv)
+{
+	return 0;
+}
+
+static inline void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
+{
+}
+
+#endif
+
+/**
+ * enum batadv_dbg_level - available log levels
+ */
+enum batadv_dbg_level {
+	/** @BATADV_DBG_BATMAN: OGM and TQ computations related messages */
+	BATADV_DBG_BATMAN	= BIT(0),
+
+	/** @BATADV_DBG_ROUTES: route added / changed / deleted */
+	BATADV_DBG_ROUTES	= BIT(1),
+
+	/** @BATADV_DBG_TT: translation table messages */
+	BATADV_DBG_TT		= BIT(2),
+
+	/** @BATADV_DBG_BLA: bridge loop avoidance messages */
+	BATADV_DBG_BLA		= BIT(3),
+
+	/** @BATADV_DBG_DAT: ARP snooping and DAT related messages */
+	BATADV_DBG_DAT		= BIT(4),
+
+	/** @BATADV_DBG_MCAST: multicast related messages */
+	BATADV_DBG_MCAST	= BIT(6),
+
+	/** @BATADV_DBG_TP_METER: throughput meter messages */
+	BATADV_DBG_TP_METER	= BIT(7),
+
+	/** @BATADV_DBG_ALL: the union of all the above log levels */
+	BATADV_DBG_ALL		= 255,
+};
+
+#ifdef CONFIG_BATMAN_ADV_DEBUG
+int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
+__printf(2, 3);
+
+/**
+ * _batadv_dbg() - Store debug output with(out) rate limiting
+ * @type: type of debug message
+ * @bat_priv: the bat priv with all the mesh interface information
+ * @ratelimited: whether output should be rate limited
+ * @fmt: format string
+ * @arg: variable arguments
+ */
+#define _batadv_dbg(type, bat_priv, ratelimited, fmt, arg...)		\
+	do {								\
+		struct batadv_priv *__batpriv = (bat_priv);		\
+		if (READ_ONCE(__batpriv->log_level) & (type) &&	\
+		    (!(ratelimited) || net_ratelimit()))		\
+			batadv_debug_log(__batpriv, fmt, ## arg);	\
+	}								\
+	while (0)
+#else /* !CONFIG_BATMAN_ADV_DEBUG */
+__printf(4, 5)
+static inline void _batadv_dbg(int type __always_unused,
+			       struct batadv_priv *bat_priv __always_unused,
+			       int ratelimited __always_unused,
+			       const char *fmt __always_unused, ...)
+{
+}
+#endif
+
+/**
+ * batadv_dbg() - Store debug output without rate limiting
+ * @type: type of debug message
+ * @bat_priv: the bat priv with all the mesh interface information
+ * @arg: format string and variable arguments
+ */
+#define batadv_dbg(type, bat_priv, arg...) \
+	_batadv_dbg(type, bat_priv, 0, ## arg)
+
+/**
+ * batadv_dbg_ratelimited() - Store debug output with rate limiting
+ * @type: type of debug message
+ * @bat_priv: the bat priv with all the mesh interface information
+ * @arg: format string and variable arguments
+ */
+#define batadv_dbg_ratelimited(type, bat_priv, arg...) \
+	_batadv_dbg(type, bat_priv, 1, ## arg)
+
+/**
+ * batadv_info() - Store message in debug buffer and print it to kmsg buffer
+ * @net_dev: the mesh interface net device
+ * @fmt: format string
+ * @arg: variable arguments
+ */
+#define batadv_info(net_dev, fmt, arg...)				\
+	do {								\
+		struct batadv_priv *_batpriv;				\
+		struct net_device *_netdev;				\
+									\
+		_netdev = (net_dev);					\
+		_batpriv = netdev_priv(_netdev);			\
+									\
+		batadv_dbg(BATADV_DBG_ALL, _batpriv, fmt, ## arg);	\
+		pr_info("%s: " fmt, _netdev->name, ## arg);		\
+	} while (0)
+
+/**
+ * batadv_err() - Store error in debug buffer and print it to kmsg buffer
+ * @net_dev: the mesh interface net device
+ * @fmt: format string
+ * @arg: variable arguments
+ */
+#define batadv_err(net_dev, fmt, arg...)				\
+	do {								\
+		struct batadv_priv *_batpriv;				\
+		struct net_device *_netdev;				\
+									\
+		_netdev = (net_dev);					\
+		_batpriv = netdev_priv(_netdev);			\
+									\
+		batadv_dbg(BATADV_DBG_ALL, _batpriv, fmt, ## arg);	\
+		pr_err("%s: " fmt, _netdev->name, ## arg);		\
+	} while (0)
+
+#endif /* _NET_BATMAN_ADV_LOG_H_ */