/* * Copyright 2007-2012 Siemens AG * * 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. * * Written by: * Dmitry Eremin-Solenikov * Sergey Lapin * Maxim Gorbachyov * Alexander Smirnov */ #include #include #include #include #include #include #include #include #include "ieee802154_i.h" #include "driver-ops.h" void ieee802154_xmit_worker(struct work_struct *work) { struct ieee802154_local *local = container_of(work, struct ieee802154_local, tx_work); struct sk_buff *skb = local->tx_skb; struct net_device *dev = skb->dev; int res; res = drv_xmit_sync(local, skb); if (res) goto err_tx; ieee802154_xmit_complete(&local->hw, skb, false); dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; return; err_tx: /* Restart the netif queue on each sub_if_data object. */ ieee802154_wake_queue(&local->hw); kfree_skb(skb); netdev_dbg(dev, "transmission failed\n"); } static netdev_tx_t ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb) { struct net_device *dev = skb->dev; int ret; if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) { u16 crc = crc_ccitt(0, skb->data, skb->len); put_unaligned_le16(crc, skb_put(skb, 2)); } /* Stop the netif queue on each sub_if_data object. */ ieee802154_stop_queue(&local->hw); /* async is priority, otherwise sync is fallback */ if (local->ops->xmit_async) { ret = drv_xmit_async(local, skb); if (ret) { ieee802154_wake_queue(&local->hw); goto err_tx; } dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; } else { local->tx_skb = skb; queue_work(local->workqueue, &local->tx_work); } return NETDEV_TX_OK; err_tx: kfree_skb(skb); return NETDEV_TX_OK; } netdev_tx_t ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev); skb->skb_iif = dev->ifindex; return ieee802154_tx(sdata->local, skb); } netdev_tx_t ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev); int rc; /* TODO we should move it to wpan_dev_hard_header and dev_hard_header * functions. The reason is wireshark will show a mac header which is * with security fields but the payload is not encrypted. */ rc = mac802154_llsec_encrypt(&sdata->sec, skb); if (rc) { netdev_warn(dev, "encryption failed: %i\n", rc); kfree_skb(skb); return NETDEV_TX_OK; } skb->skb_iif = dev->ifindex; return ieee802154_tx(sdata->local, skb); } vate-remove&id=966d2b04e070bc040319aaebfec09e0144dc3341'>drivers/usb/host/ehci-ppc-of.c
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /drivers/usb/host/ehci-ppc-of.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'drivers/usb/host/ehci-ppc-of.c')