/* This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * 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; 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(); list_for_each_entry_rcu(sdata, &local->interfaces, list) { if (!sdata->dev) continue; netif_wake_queue(sdata->dev); } rcu_read_unlock(); } EXPORT_SYMBOL(ieee802154_wake_queue); 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(); } EXPORT_SYMBOL(ieee802154_stop_queue); enum hrtimer_restart ieee802154_xmit_ifs_timer(struct hrtimer *timer) { struct ieee802154_local *local = container_of(timer, struct ieee802154_local, ifs_timer); ieee802154_wake_queue(&local->hw); return HRTIMER_NORESTART; } void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, bool ifs_handling) { if (ifs_handling) { struct ieee802154_local *local = hw_to_local(hw); 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_wake_queue(hw); } dev_consume_skb_any(skb); } EXPORT_SYMBOL(ieee802154_xmit_complete); void ieee802154_stop_device(struct ieee802154_local *local) { flush_workqueue(local->workqueue); hrtimer_cancel(&local->ifs_timer); drv_stop(local); } value=''/>
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authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /net/ipv4/proc.c
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'net/ipv4/proc.c')