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, 86 insertions, 0 deletions

diff --git a/net/mac80211/led.h b/net/mac80211/led.h
new file mode 100644
index 000000000..d25f13346
--- /dev/null
+++ b/net/mac80211/led.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2006, Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/leds.h>
+#include "ieee80211_i.h"
+
+#define MAC80211_BLINK_DELAY 50 /* ms */
+
+static inline void ieee80211_led_rx(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (!atomic_read(&local->rx_led_active))
+		return;
+	led_trigger_blink_oneshot(&local->rx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
+#endif
+}
+
+static inline void ieee80211_led_tx(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (!atomic_read(&local->tx_led_active))
+		return;
+	led_trigger_blink_oneshot(&local->tx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
+#endif
+}
+
+#ifdef CONFIG_MAC80211_LEDS
+void ieee80211_led_assoc(struct ieee80211_local *local,
+			 bool associated);
+void ieee80211_led_radio(struct ieee80211_local *local,
+			 bool enabled);
+void ieee80211_alloc_led_names(struct ieee80211_local *local);
+void ieee80211_free_led_names(struct ieee80211_local *local);
+void ieee80211_led_init(struct ieee80211_local *local);
+void ieee80211_led_exit(struct ieee80211_local *local);
+void ieee80211_mod_tpt_led_trig(struct ieee80211_local *local,
+				unsigned int types_on, unsigned int types_off);
+#else
+static inline void ieee80211_led_assoc(struct ieee80211_local *local,
+				       bool associated)
+{
+}
+static inline void ieee80211_led_radio(struct ieee80211_local *local,
+				       bool enabled)
+{
+}
+static inline void ieee80211_alloc_led_names(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_free_led_names(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_led_init(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_led_exit(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_mod_tpt_led_trig(struct ieee80211_local *local,
+					      unsigned int types_on,
+					      unsigned int types_off)
+{
+}
+#endif
+
+static inline void
+ieee80211_tpt_led_trig_tx(struct ieee80211_local *local, int bytes)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (atomic_read(&local->tpt_led_active))
+		local->tpt_led_trigger->tx_bytes += bytes;
+#endif
+}
+
+static inline void
+ieee80211_tpt_led_trig_rx(struct ieee80211_local *local, int bytes)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (atomic_read(&local->tpt_led_active))
+		local->tpt_led_trigger->rx_bytes += bytes;
+#endif
+}