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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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c2355e1ab9
The bonding driver currently modifies the netpoll structure in its xmit path while sending frames from netpoll. This is racy, as other cpus can access the netpoll structure in parallel. Since the bonding driver points np->dev to a slave device, other cpus can inadvertently attempt to send data directly to slave devices, leading to improper locking with the bonding master, lost frames, and deadlocks. This patch fixes that up. This patch also removes the real_dev pointer from the netpoll structure as that data is really only used by bonding in the poll_controller, and we can emulate its behavior by check each slave for IS_UP. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
158 lines
3.4 KiB
C
158 lines
3.4 KiB
C
/*
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* Common code for low-level network console, dump, and debugger code
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*
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* Derived from netconsole, kgdb-over-ethernet, and netdump patches
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*/
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#ifndef _LINUX_NETPOLL_H
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#define _LINUX_NETPOLL_H
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#include <linux/netdevice.h>
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#include <linux/interrupt.h>
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#include <linux/rcupdate.h>
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#include <linux/list.h>
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struct netpoll {
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struct net_device *dev;
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char dev_name[IFNAMSIZ];
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const char *name;
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void (*rx_hook)(struct netpoll *, int, char *, int);
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__be32 local_ip, remote_ip;
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u16 local_port, remote_port;
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u8 remote_mac[ETH_ALEN];
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struct list_head rx; /* rx_np list element */
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};
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struct netpoll_info {
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atomic_t refcnt;
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int rx_flags;
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spinlock_t rx_lock;
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struct list_head rx_np; /* netpolls that registered an rx_hook */
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struct sk_buff_head arp_tx; /* list of arp requests to reply to */
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struct sk_buff_head txq;
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struct delayed_work tx_work;
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struct netpoll *netpoll;
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};
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void netpoll_poll_dev(struct net_device *dev);
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void netpoll_poll(struct netpoll *np);
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void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
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void netpoll_print_options(struct netpoll *np);
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int netpoll_parse_options(struct netpoll *np, char *opt);
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int __netpoll_setup(struct netpoll *np);
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int netpoll_setup(struct netpoll *np);
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int netpoll_trap(void);
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void netpoll_set_trap(int trap);
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void __netpoll_cleanup(struct netpoll *np);
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void netpoll_cleanup(struct netpoll *np);
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int __netpoll_rx(struct sk_buff *skb);
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void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
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struct net_device *dev);
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static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
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{
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netpoll_send_skb_on_dev(np, skb, np->dev);
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}
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#ifdef CONFIG_NETPOLL
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static inline bool netpoll_rx(struct sk_buff *skb)
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{
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struct netpoll_info *npinfo;
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unsigned long flags;
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bool ret = false;
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local_irq_save(flags);
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npinfo = rcu_dereference_bh(skb->dev->npinfo);
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if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
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goto out;
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spin_lock(&npinfo->rx_lock);
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/* check rx_flags again with the lock held */
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if (npinfo->rx_flags && __netpoll_rx(skb))
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ret = true;
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spin_unlock(&npinfo->rx_lock);
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out:
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local_irq_restore(flags);
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return ret;
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}
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static inline int netpoll_rx_on(struct sk_buff *skb)
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{
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struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
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return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
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}
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static inline int netpoll_receive_skb(struct sk_buff *skb)
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{
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if (!list_empty(&skb->dev->napi_list))
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return netpoll_rx(skb);
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return 0;
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}
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static inline void *netpoll_poll_lock(struct napi_struct *napi)
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{
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struct net_device *dev = napi->dev;
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if (dev && dev->npinfo) {
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spin_lock(&napi->poll_lock);
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napi->poll_owner = smp_processor_id();
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return napi;
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}
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return NULL;
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}
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static inline void netpoll_poll_unlock(void *have)
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{
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struct napi_struct *napi = have;
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if (napi) {
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napi->poll_owner = -1;
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spin_unlock(&napi->poll_lock);
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}
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}
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static inline int netpoll_tx_running(struct net_device *dev)
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{
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return irqs_disabled();
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}
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#else
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static inline bool netpoll_rx(struct sk_buff *skb)
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{
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return 0;
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}
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static inline int netpoll_rx_on(struct sk_buff *skb)
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{
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return 0;
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}
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static inline int netpoll_receive_skb(struct sk_buff *skb)
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{
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return 0;
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}
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static inline void *netpoll_poll_lock(struct napi_struct *napi)
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{
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return NULL;
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}
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static inline void netpoll_poll_unlock(void *have)
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{
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}
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static inline void netpoll_netdev_init(struct net_device *dev)
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{
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}
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static inline int netpoll_tx_running(struct net_device *dev)
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{
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return 0;
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}
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#endif
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#endif
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