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, 377 insertions, 0 deletions

diff --git a/net/mac80211/led.c b/net/mac80211/led.c
new file mode 100644
index 000000000..b5600d223
--- /dev/null
+++ b/net/mac80211/led.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2006, Johannes Berg <johannes@sipsolutions.net>
+ */
+
+/* just for IFNAMSIZ */
+#include <linux/if.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include "led.h"
+
+void ieee80211_led_assoc(struct ieee80211_local *local, bool associated)
+{
+	if (!atomic_read(&local->assoc_led_active))
+		return;
+	if (associated)
+		led_trigger_event(&local->assoc_led, LED_FULL);
+	else
+		led_trigger_event(&local->assoc_led, LED_OFF);
+}
+
+void ieee80211_led_radio(struct ieee80211_local *local, bool enabled)
+{
+	if (!atomic_read(&local->radio_led_active))
+		return;
+	if (enabled)
+		led_trigger_event(&local->radio_led, LED_FULL);
+	else
+		led_trigger_event(&local->radio_led, LED_OFF);
+}
+
+void ieee80211_alloc_led_names(struct ieee80211_local *local)
+{
+	local->rx_led.name = kasprintf(GFP_KERNEL, "%srx",
+				       wiphy_name(local->hw.wiphy));
+	local->tx_led.name = kasprintf(GFP_KERNEL, "%stx",
+				       wiphy_name(local->hw.wiphy));
+	local->assoc_led.name = kasprintf(GFP_KERNEL, "%sassoc",
+					  wiphy_name(local->hw.wiphy));
+	local->radio_led.name = kasprintf(GFP_KERNEL, "%sradio",
+					  wiphy_name(local->hw.wiphy));
+}
+
+void ieee80211_free_led_names(struct ieee80211_local *local)
+{
+	kfree(local->rx_led.name);
+	kfree(local->tx_led.name);
+	kfree(local->assoc_led.name);
+	kfree(local->radio_led.name);
+}
+
+static int ieee80211_tx_led_activate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     tx_led);
+
+	atomic_inc(&local->tx_led_active);
+
+	return 0;
+}
+
+static void ieee80211_tx_led_deactivate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     tx_led);
+
+	atomic_dec(&local->tx_led_active);
+}
+
+static int ieee80211_rx_led_activate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     rx_led);
+
+	atomic_inc(&local->rx_led_active);
+
+	return 0;
+}
+
+static void ieee80211_rx_led_deactivate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     rx_led);
+
+	atomic_dec(&local->rx_led_active);
+}
+
+static int ieee80211_assoc_led_activate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     assoc_led);
+
+	atomic_inc(&local->assoc_led_active);
+
+	return 0;
+}
+
+static void ieee80211_assoc_led_deactivate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     assoc_led);
+
+	atomic_dec(&local->assoc_led_active);
+}
+
+static int ieee80211_radio_led_activate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     radio_led);
+
+	atomic_inc(&local->radio_led_active);
+
+	return 0;
+}
+
+static void ieee80211_radio_led_deactivate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     radio_led);
+
+	atomic_dec(&local->radio_led_active);
+}
+
+static int ieee80211_tpt_led_activate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     tpt_led);
+
+	atomic_inc(&local->tpt_led_active);
+
+	return 0;
+}
+
+static void ieee80211_tpt_led_deactivate(struct led_classdev *led_cdev)
+{
+	struct ieee80211_local *local = container_of(led_cdev->trigger,
+						     struct ieee80211_local,
+						     tpt_led);
+
+	atomic_dec(&local->tpt_led_active);
+}
+
+void ieee80211_led_init(struct ieee80211_local *local)
+{
+	atomic_set(&local->rx_led_active, 0);
+	local->rx_led.activate = ieee80211_rx_led_activate;
+	local->rx_led.deactivate = ieee80211_rx_led_deactivate;
+	if (local->rx_led.name && led_trigger_register(&local->rx_led)) {
+		kfree(local->rx_led.name);
+		local->rx_led.name = NULL;
+	}
+
+	atomic_set(&local->tx_led_active, 0);
+	local->tx_led.activate = ieee80211_tx_led_activate;
+	local->tx_led.deactivate = ieee80211_tx_led_deactivate;
+	if (local->tx_led.name && led_trigger_register(&local->tx_led)) {
+		kfree(local->tx_led.name);
+		local->tx_led.name = NULL;
+	}
+
+	atomic_set(&local->assoc_led_active, 0);
+	local->assoc_led.activate = ieee80211_assoc_led_activate;
+	local->assoc_led.deactivate = ieee80211_assoc_led_deactivate;
+	if (local->assoc_led.name && led_trigger_register(&local->assoc_led)) {
+		kfree(local->assoc_led.name);
+		local->assoc_led.name = NULL;
+	}
+
+	atomic_set(&local->radio_led_active, 0);
+	local->radio_led.activate = ieee80211_radio_led_activate;
+	local->radio_led.deactivate = ieee80211_radio_led_deactivate;
+	if (local->radio_led.name && led_trigger_register(&local->radio_led)) {
+		kfree(local->radio_led.name);
+		local->radio_led.name = NULL;
+	}
+
+	atomic_set(&local->tpt_led_active, 0);
+	if (local->tpt_led_trigger) {
+		local->tpt_led.activate = ieee80211_tpt_led_activate;
+		local->tpt_led.deactivate = ieee80211_tpt_led_deactivate;
+		if (led_trigger_register(&local->tpt_led)) {
+			kfree(local->tpt_led_trigger);
+			local->tpt_led_trigger = NULL;
+		}
+	}
+}
+
+void ieee80211_led_exit(struct ieee80211_local *local)
+{
+	if (local->radio_led.name)
+		led_trigger_unregister(&local->radio_led);
+	if (local->assoc_led.name)
+		led_trigger_unregister(&local->assoc_led);
+	if (local->tx_led.name)
+		led_trigger_unregister(&local->tx_led);
+	if (local->rx_led.name)
+		led_trigger_unregister(&local->rx_led);
+
+	if (local->tpt_led_trigger) {
+		led_trigger_unregister(&local->tpt_led);
+		kfree(local->tpt_led_trigger);
+	}
+}
+
+const char *__ieee80211_get_radio_led_name(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	return local->radio_led.name;
+}
+EXPORT_SYMBOL(__ieee80211_get_radio_led_name);
+
+const char *__ieee80211_get_assoc_led_name(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	return local->assoc_led.name;
+}
+EXPORT_SYMBOL(__ieee80211_get_assoc_led_name);
+
+const char *__ieee80211_get_tx_led_name(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	return local->tx_led.name;
+}
+EXPORT_SYMBOL(__ieee80211_get_tx_led_name);
+
+const char *__ieee80211_get_rx_led_name(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	return local->rx_led.name;
+}
+EXPORT_SYMBOL(__ieee80211_get_rx_led_name);
+
+static unsigned long tpt_trig_traffic(struct ieee80211_local *local,
+				      struct tpt_led_trigger *tpt_trig)
+{
+	unsigned long traffic, delta;
+
+	traffic = tpt_trig->tx_bytes + tpt_trig->rx_bytes;
+
+	delta = traffic - tpt_trig->prev_traffic;
+	tpt_trig->prev_traffic = traffic;
+	return DIV_ROUND_UP(delta, 1024 / 8);
+}
+
+static void tpt_trig_timer(struct timer_list *t)
+{
+	struct tpt_led_trigger *tpt_trig = timer_container_of(tpt_trig, t,
+							      timer);
+	struct ieee80211_local *local = tpt_trig->local;
+	unsigned long on, off, tpt;
+	int i;
+
+	if (!tpt_trig->running)
+		return;
+
+	mod_timer(&tpt_trig->timer, round_jiffies(jiffies + HZ));
+
+	tpt = tpt_trig_traffic(local, tpt_trig);
+
+	/* default to just solid on */
+	on = 1;
+	off = 0;
+
+	for (i = tpt_trig->blink_table_len - 1; i >= 0; i--) {
+		if (tpt_trig->blink_table[i].throughput < 0 ||
+		    tpt > tpt_trig->blink_table[i].throughput) {
+			off = tpt_trig->blink_table[i].blink_time / 2;
+			on = tpt_trig->blink_table[i].blink_time - off;
+			break;
+		}
+	}
+
+	led_trigger_blink(&local->tpt_led, on, off);
+}
+
+const char *
+__ieee80211_create_tpt_led_trigger(struct ieee80211_hw *hw,
+				   unsigned int flags,
+				   const struct ieee80211_tpt_blink *blink_table,
+				   unsigned int blink_table_len)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct tpt_led_trigger *tpt_trig;
+
+	if (WARN_ON(local->tpt_led_trigger))
+		return NULL;
+
+	tpt_trig = kzalloc_obj(struct tpt_led_trigger);
+	if (!tpt_trig)
+		return NULL;
+
+	snprintf(tpt_trig->name, sizeof(tpt_trig->name),
+		 "%stpt", wiphy_name(local->hw.wiphy));
+
+	local->tpt_led.name = tpt_trig->name;
+
+	tpt_trig->blink_table = blink_table;
+	tpt_trig->blink_table_len = blink_table_len;
+	tpt_trig->want = flags;
+	tpt_trig->local = local;
+
+	timer_setup(&tpt_trig->timer, tpt_trig_timer, 0);
+
+	local->tpt_led_trigger = tpt_trig;
+
+	return tpt_trig->name;
+}
+EXPORT_SYMBOL(__ieee80211_create_tpt_led_trigger);
+
+static void ieee80211_start_tpt_led_trig(struct ieee80211_local *local)
+{
+	struct tpt_led_trigger *tpt_trig = local->tpt_led_trigger;
+
+	if (tpt_trig->running)
+		return;
+
+	/* reset traffic */
+	tpt_trig_traffic(local, tpt_trig);
+	tpt_trig->running = true;
+
+	tpt_trig_timer(&tpt_trig->timer);
+	mod_timer(&tpt_trig->timer, round_jiffies(jiffies + HZ));
+}
+
+static void ieee80211_stop_tpt_led_trig(struct ieee80211_local *local)
+{
+	struct tpt_led_trigger *tpt_trig = local->tpt_led_trigger;
+
+	if (!tpt_trig->running)
+		return;
+
+	tpt_trig->running = false;
+	timer_delete_sync(&tpt_trig->timer);
+
+	led_trigger_event(&local->tpt_led, LED_OFF);
+}
+
+void ieee80211_mod_tpt_led_trig(struct ieee80211_local *local,
+				unsigned int types_on, unsigned int types_off)
+{
+	struct tpt_led_trigger *tpt_trig = local->tpt_led_trigger;
+	bool allowed;
+
+	WARN_ON(types_on & types_off);
+
+	if (!tpt_trig)
+		return;
+
+	tpt_trig->active &= ~types_off;
+	tpt_trig->active |= types_on;
+
+	/*
+	 * Regardless of wanted state, we shouldn't blink when
+	 * the radio is disabled -- this can happen due to some
+	 * code ordering issues with __ieee80211_recalc_idle()
+	 * being called before the radio is started.
+	 */
+	allowed = tpt_trig->active & IEEE80211_TPT_LEDTRIG_FL_RADIO;
+
+	if (!allowed || !(tpt_trig->active & tpt_trig->want))
+		ieee80211_stop_tpt_led_trig(local);
+	else
+		ieee80211_start_tpt_led_trig(local);
+}