/* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* For the statistics structure. */ #include #include #include #include #include #include #include #include #include #include #include #include /* * Only allow IP over NET/ROM frames through if the netrom device is up. */ int nr_rx_ip(struct sk_buff *skb, struct net_device *dev) { struct net_device_stats *stats = &dev->stats; if (!netif_running(dev)) { stats->rx_dropped++; return 0; } stats->rx_packets++; stats->rx_bytes += skb->len; skb->protocol = htons(ETH_P_IP); /* Spoof incoming device */ skb->dev = dev; skb->mac_header = skb->network_header; skb_reset_network_header(skb); skb->pkt_type = PACKET_HOST; netif_rx(skb); return 1; } static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned int len) { unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN); memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len); buff[6] &= ~AX25_CBIT; buff[6] &= ~AX25_EBIT; buff[6] |= AX25_SSSID_SPARE; buff += AX25_ADDR_LEN; if (daddr != NULL) memcpy(buff, daddr, dev->addr_len); buff[6] &= ~AX25_CBIT; buff[6] |= AX25_EBIT; buff[6] |= AX25_SSSID_SPARE; buff += AX25_ADDR_LEN; *buff++ = sysctl_netrom_network_ttl_initialiser; *buff++ = NR_PROTO_IP; *buff++ = NR_PROTO_IP; *buff++ = 0; *buff++ = 0; *buff++ = NR_PROTOEXT; if (daddr != NULL) return 37; return -37; } static int __must_check nr_set_mac_address(struct net_device *dev, void *addr) { struct sockaddr *sa = addr; int err; if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) return 0; if (dev->flags & IFF_UP) { err = ax25_listen_register((ax25_address *)sa->sa_data, NULL); if (err) return err; ax25_listen_release((ax25_address *)dev->dev_addr, NULL); } memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); return 0; } static int nr_open(struct net_device *dev) { int err; err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL); if (err) return err; netif_start_queue(dev); return 0; } static int nr_close(struct net_device *dev) { ax25_listen_release((ax25_address *)dev->dev_addr, NULL); netif_stop_queue(dev); return 0; } static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev) { struct net_device_stats *stats = &dev->stats; unsigned int len = skb->len; if (!nr_route_frame(skb, NULL)) { kfree_skb(skb); stats->tx_errors++; return NETDEV_TX_OK; } stats->tx_packets++; stats->tx_bytes += len; return NETDEV_TX_OK; } static const struct header_ops nr_header_ops = { .create = nr_header, }; static const struct net_device_ops nr_netdev_ops = { .ndo_open = nr_open, .ndo_stop = nr_close, .ndo_start_xmit = nr_xmit, .ndo_set_mac_address = nr_set_mac_address, }; void nr_setup(struct net_device *dev) { dev->mtu = NR_MAX_PACKET_SIZE; dev->netdev_ops = &nr_netdev_ops; dev->header_ops = &nr_header_ops; dev->hard_header_len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; dev->addr_len = AX25_ADDR_LEN; dev->type = ARPHRD_NETROM; /* New-style flags. */ dev->flags = IFF_NOARP; } value='8'>8space:mode:
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 /include/uapi/xen
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 'include/uapi/xen')