From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- net/mac802154/util.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) create mode 100644 net/mac802154/util.c (limited to 'net/mac802154/util.c') diff --git a/net/mac802154/util.c b/net/mac802154/util.c new file mode 100644 index 000000000..ebc9a8521 --- /dev/null +++ b/net/mac802154/util.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Authors: + * Alexander Aring + * + * Based on: net/mac80211/util.c + */ + +#include "ieee802154_i.h" +#include "driver-ops.h" + +/* privid for wpan_phys to determine whether they belong to us or not */ +const void *const mac802154_wpan_phy_privid = &mac802154_wpan_phy_privid; + +/** + * ieee802154_wake_queue - wake ieee802154 queue + * @hw: main hardware object + * + * Tranceivers usually have either one transmit framebuffer or one framebuffer + * for both transmitting and receiving. Hence, the core currently only handles + * one frame at a time for each phy, which means we had to stop the queue to + * avoid new skb to come during the transmission. The queue then needs to be + * woken up after the operation. + */ +static void ieee802154_wake_queue(struct ieee802154_hw *hw) +{ + struct ieee802154_local *local = hw_to_local(hw); + struct ieee802154_sub_if_data *sdata; + + rcu_read_lock(); + clear_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!sdata->dev) + continue; + + netif_wake_queue(sdata->dev); + } + rcu_read_unlock(); +} + +/** + * ieee802154_stop_queue - stop ieee802154 queue + * @hw: main hardware object + * + * Tranceivers usually have either one transmit framebuffer or one framebuffer + * for both transmitting and receiving. Hence, the core currently only handles + * one frame at a time for each phy, which means we need to tell upper layers to + * stop giving us new skbs while we are busy with the transmitted one. The queue + * must then be stopped before transmitting. + */ +static void ieee802154_stop_queue(struct ieee802154_hw *hw) +{ + struct ieee802154_local *local = hw_to_local(hw); + struct ieee802154_sub_if_data *sdata; + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!sdata->dev) + continue; + + netif_stop_queue(sdata->dev); + } + rcu_read_unlock(); +} + +void ieee802154_hold_queue(struct ieee802154_local *local) +{ + unsigned long flags; + + spin_lock_irqsave(&local->phy->queue_lock, flags); + if (!atomic_fetch_inc(&local->phy->hold_txs)) + ieee802154_stop_queue(&local->hw); + spin_unlock_irqrestore(&local->phy->queue_lock, flags); +} + +void ieee802154_release_queue(struct ieee802154_local *local) +{ + unsigned long flags; + + spin_lock_irqsave(&local->phy->queue_lock, flags); + if (atomic_dec_and_test(&local->phy->hold_txs)) + ieee802154_wake_queue(&local->hw); + spin_unlock_irqrestore(&local->phy->queue_lock, flags); +} + +void ieee802154_disable_queue(struct ieee802154_local *local) +{ + struct ieee802154_sub_if_data *sdata; + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!sdata->dev) + continue; + + netif_tx_disable(sdata->dev); + } + rcu_read_unlock(); +} + +enum hrtimer_restart ieee802154_xmit_ifs_timer(struct hrtimer *timer) +{ + struct ieee802154_local *local = + container_of(timer, struct ieee802154_local, ifs_timer); + + ieee802154_release_queue(local); + + return HRTIMER_NORESTART; +} + +void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, + bool ifs_handling) +{ + struct ieee802154_local *local = hw_to_local(hw); + + local->tx_result = IEEE802154_SUCCESS; + + if (ifs_handling) { + u8 max_sifs_size; + + /* If transceiver sets CRC on his own we need to use lifs + * threshold len above 16 otherwise 18, because it's not + * part of skb->len. + */ + if (hw->flags & IEEE802154_HW_TX_OMIT_CKSUM) + max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE - + IEEE802154_FCS_LEN; + else + max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE; + + if (skb->len > max_sifs_size) + hrtimer_start(&local->ifs_timer, + hw->phy->lifs_period * NSEC_PER_USEC, + HRTIMER_MODE_REL); + else + hrtimer_start(&local->ifs_timer, + hw->phy->sifs_period * NSEC_PER_USEC, + HRTIMER_MODE_REL); + } else { + ieee802154_release_queue(local); + } + + dev_consume_skb_any(skb); + if (atomic_dec_and_test(&hw->phy->ongoing_txs)) + wake_up(&hw->phy->sync_txq); +} +EXPORT_SYMBOL(ieee802154_xmit_complete); + +void ieee802154_xmit_error(struct ieee802154_hw *hw, struct sk_buff *skb, + int reason) +{ + struct ieee802154_local *local = hw_to_local(hw); + + local->tx_result = reason; + ieee802154_release_queue(local); + dev_kfree_skb_any(skb); + if (atomic_dec_and_test(&hw->phy->ongoing_txs)) + wake_up(&hw->phy->sync_txq); +} +EXPORT_SYMBOL(ieee802154_xmit_error); + +void ieee802154_xmit_hw_error(struct ieee802154_hw *hw, struct sk_buff *skb) +{ + ieee802154_xmit_error(hw, skb, IEEE802154_SYSTEM_ERROR); +} +EXPORT_SYMBOL(ieee802154_xmit_hw_error); + +void ieee802154_stop_device(struct ieee802154_local *local) +{ + flush_workqueue(local->workqueue); + hrtimer_cancel(&local->ifs_timer); + drv_stop(local); +} -- cgit v1.3.1