mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-26 23:40:55 +07:00
50624c934d
There is currently serialization network namespaces exiting and network devices exiting as the final part of netdev_run_todo does not happen under the rtnl_lock. This is compounded by the fact that the only list of devices unregistering in netdev_run_todo is local to the netdev_run_todo. This lack of serialization in extreme cases results in network devices unregistering in netdev_run_todo after the loopback device of their network namespace has been freed (making dst_ifdown unsafe), and after the their network namespace has exited (making the NETDEV_UNREGISTER, and NETDEV_UNREGISTER_FINAL callbacks unsafe). Add the missing serialization by a per network namespace count of how many network devices are unregistering and having a wait queue that is woken up whenever the count is decreased. The count and wait queue allow default_device_exit_batch to wait until all of the unregistration activity for a network namespace has finished before proceeding to unregister the loopback device and then allowing the network namespace to exit. Only a single global wait queue is used because there is a single global lock, and there is a single waiter, per network namespace wait queues would be a waste of resources. The per network namespace count of unregistering devices gives a progress guarantee because the number of network devices unregistering in an exiting network namespace must ultimately drop to zero (assuming network device unregistration completes). The basic logic remains the same as in v1. This patch is now half comment and half rtnl_lock_unregistering an expanded version of wait_event performs no extra work in the common case where no network devices are unregistering when we get to default_device_exit_batch. Reported-by: Francesco Ruggeri <fruggeri@aristanetworks.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
385 lines
8.8 KiB
C
385 lines
8.8 KiB
C
/*
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* Operations on the network namespace
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*/
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#ifndef __NET_NET_NAMESPACE_H
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#define __NET_NET_NAMESPACE_H
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#include <linux/atomic.h>
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#include <linux/workqueue.h>
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#include <linux/list.h>
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#include <linux/sysctl.h>
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#include <net/netns/core.h>
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#include <net/netns/mib.h>
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#include <net/netns/unix.h>
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#include <net/netns/packet.h>
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#include <net/netns/ipv4.h>
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#include <net/netns/ipv6.h>
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#include <net/netns/sctp.h>
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#include <net/netns/dccp.h>
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#include <net/netns/netfilter.h>
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#include <net/netns/x_tables.h>
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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#include <net/netns/conntrack.h>
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#endif
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#include <net/netns/xfrm.h>
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struct user_namespace;
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struct proc_dir_entry;
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struct net_device;
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struct sock;
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struct ctl_table_header;
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struct net_generic;
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struct sock;
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struct netns_ipvs;
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#define NETDEV_HASHBITS 8
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#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
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struct net {
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atomic_t passive; /* To decided when the network
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* namespace should be freed.
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*/
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atomic_t count; /* To decided when the network
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* namespace should be shut down.
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*/
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#ifdef NETNS_REFCNT_DEBUG
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atomic_t use_count; /* To track references we
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* destroy on demand
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*/
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#endif
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spinlock_t rules_mod_lock;
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struct list_head list; /* list of network namespaces */
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struct list_head cleanup_list; /* namespaces on death row */
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struct list_head exit_list; /* Use only net_mutex */
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struct user_namespace *user_ns; /* Owning user namespace */
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unsigned int proc_inum;
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struct proc_dir_entry *proc_net;
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struct proc_dir_entry *proc_net_stat;
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#ifdef CONFIG_SYSCTL
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struct ctl_table_set sysctls;
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#endif
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struct sock *rtnl; /* rtnetlink socket */
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struct sock *genl_sock;
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struct list_head dev_base_head;
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struct hlist_head *dev_name_head;
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struct hlist_head *dev_index_head;
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unsigned int dev_base_seq; /* protected by rtnl_mutex */
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int ifindex;
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unsigned int dev_unreg_count;
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/* core fib_rules */
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struct list_head rules_ops;
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struct net_device *loopback_dev; /* The loopback */
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struct netns_core core;
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struct netns_mib mib;
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struct netns_packet packet;
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struct netns_unix unx;
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struct netns_ipv4 ipv4;
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#if IS_ENABLED(CONFIG_IPV6)
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struct netns_ipv6 ipv6;
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#endif
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#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
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struct netns_sctp sctp;
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#endif
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#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
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struct netns_dccp dccp;
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#endif
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#ifdef CONFIG_NETFILTER
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struct netns_nf nf;
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struct netns_xt xt;
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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struct netns_ct ct;
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#endif
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#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
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struct netns_nf_frag nf_frag;
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#endif
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struct sock *nfnl;
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struct sock *nfnl_stash;
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#endif
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#ifdef CONFIG_WEXT_CORE
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struct sk_buff_head wext_nlevents;
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#endif
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struct net_generic __rcu *gen;
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/* Note : following structs are cache line aligned */
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#ifdef CONFIG_XFRM
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struct netns_xfrm xfrm;
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#endif
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#if IS_ENABLED(CONFIG_IP_VS)
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struct netns_ipvs *ipvs;
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#endif
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struct sock *diag_nlsk;
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atomic_t fnhe_genid;
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};
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/*
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* ifindex generation is per-net namespace, and loopback is
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* always the 1st device in ns (see net_dev_init), thus any
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* loopback device should get ifindex 1
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*/
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#define LOOPBACK_IFINDEX 1
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#include <linux/seq_file_net.h>
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/* Init's network namespace */
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extern struct net init_net;
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#ifdef CONFIG_NET_NS
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extern struct net *copy_net_ns(unsigned long flags,
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struct user_namespace *user_ns, struct net *old_net);
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#else /* CONFIG_NET_NS */
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#include <linux/sched.h>
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#include <linux/nsproxy.h>
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static inline struct net *copy_net_ns(unsigned long flags,
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struct user_namespace *user_ns, struct net *old_net)
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{
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if (flags & CLONE_NEWNET)
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return ERR_PTR(-EINVAL);
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return old_net;
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}
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#endif /* CONFIG_NET_NS */
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extern struct list_head net_namespace_list;
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extern struct net *get_net_ns_by_pid(pid_t pid);
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extern struct net *get_net_ns_by_fd(int pid);
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#ifdef CONFIG_NET_NS
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extern void __put_net(struct net *net);
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static inline struct net *get_net(struct net *net)
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{
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atomic_inc(&net->count);
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return net;
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}
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static inline struct net *maybe_get_net(struct net *net)
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{
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/* Used when we know struct net exists but we
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* aren't guaranteed a previous reference count
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* exists. If the reference count is zero this
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* function fails and returns NULL.
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*/
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if (!atomic_inc_not_zero(&net->count))
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net = NULL;
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return net;
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}
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static inline void put_net(struct net *net)
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{
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if (atomic_dec_and_test(&net->count))
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__put_net(net);
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}
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static inline
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int net_eq(const struct net *net1, const struct net *net2)
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{
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return net1 == net2;
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}
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extern void net_drop_ns(void *);
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#else
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static inline struct net *get_net(struct net *net)
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{
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return net;
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}
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static inline void put_net(struct net *net)
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{
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}
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static inline struct net *maybe_get_net(struct net *net)
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{
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return net;
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}
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static inline
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int net_eq(const struct net *net1, const struct net *net2)
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{
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return 1;
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}
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#define net_drop_ns NULL
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#endif
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#ifdef NETNS_REFCNT_DEBUG
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static inline struct net *hold_net(struct net *net)
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{
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if (net)
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atomic_inc(&net->use_count);
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return net;
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}
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static inline void release_net(struct net *net)
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{
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if (net)
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atomic_dec(&net->use_count);
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}
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#else
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static inline struct net *hold_net(struct net *net)
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{
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return net;
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}
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static inline void release_net(struct net *net)
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{
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}
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#endif
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#ifdef CONFIG_NET_NS
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static inline void write_pnet(struct net **pnet, struct net *net)
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{
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*pnet = net;
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}
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static inline struct net *read_pnet(struct net * const *pnet)
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{
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return *pnet;
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}
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#else
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#define write_pnet(pnet, net) do { (void)(net);} while (0)
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#define read_pnet(pnet) (&init_net)
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#endif
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#define for_each_net(VAR) \
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list_for_each_entry(VAR, &net_namespace_list, list)
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#define for_each_net_rcu(VAR) \
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list_for_each_entry_rcu(VAR, &net_namespace_list, list)
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#ifdef CONFIG_NET_NS
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#define __net_init
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#define __net_exit
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#define __net_initdata
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#define __net_initconst
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#else
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#define __net_init __init
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#define __net_exit __exit_refok
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#define __net_initdata __initdata
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#define __net_initconst __initconst
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#endif
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struct pernet_operations {
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struct list_head list;
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int (*init)(struct net *net);
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void (*exit)(struct net *net);
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void (*exit_batch)(struct list_head *net_exit_list);
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int *id;
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size_t size;
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};
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/*
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* Use these carefully. If you implement a network device and it
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* needs per network namespace operations use device pernet operations,
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* otherwise use pernet subsys operations.
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*
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* Network interfaces need to be removed from a dying netns _before_
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* subsys notifiers can be called, as most of the network code cleanup
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* (which is done from subsys notifiers) runs with the assumption that
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* dev_remove_pack has been called so no new packets will arrive during
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* and after the cleanup functions have been called. dev_remove_pack
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* is not per namespace so instead the guarantee of no more packets
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* arriving in a network namespace is provided by ensuring that all
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* network devices and all sockets have left the network namespace
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* before the cleanup methods are called.
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*
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* For the longest time the ipv4 icmp code was registered as a pernet
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* device which caused kernel oops, and panics during network
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* namespace cleanup. So please don't get this wrong.
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*/
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extern int register_pernet_subsys(struct pernet_operations *);
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extern void unregister_pernet_subsys(struct pernet_operations *);
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extern int register_pernet_device(struct pernet_operations *);
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extern void unregister_pernet_device(struct pernet_operations *);
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struct ctl_table;
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struct ctl_table_header;
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#ifdef CONFIG_SYSCTL
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extern int net_sysctl_init(void);
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extern struct ctl_table_header *register_net_sysctl(struct net *net,
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const char *path, struct ctl_table *table);
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extern void unregister_net_sysctl_table(struct ctl_table_header *header);
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#else
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static inline int net_sysctl_init(void) { return 0; }
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static inline struct ctl_table_header *register_net_sysctl(struct net *net,
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const char *path, struct ctl_table *table)
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{
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return NULL;
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}
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static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
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{
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}
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#endif
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static inline int rt_genid_ipv4(struct net *net)
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{
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return atomic_read(&net->ipv4.rt_genid);
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}
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static inline void rt_genid_bump_ipv4(struct net *net)
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{
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atomic_inc(&net->ipv4.rt_genid);
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}
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#if IS_ENABLED(CONFIG_IPV6)
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static inline int rt_genid_ipv6(struct net *net)
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{
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return atomic_read(&net->ipv6.rt_genid);
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}
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static inline void rt_genid_bump_ipv6(struct net *net)
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{
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atomic_inc(&net->ipv6.rt_genid);
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}
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#else
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static inline int rt_genid_ipv6(struct net *net)
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{
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return 0;
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}
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static inline void rt_genid_bump_ipv6(struct net *net)
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{
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}
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#endif
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/* For callers who don't really care about whether it's IPv4 or IPv6 */
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static inline void rt_genid_bump_all(struct net *net)
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{
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rt_genid_bump_ipv4(net);
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rt_genid_bump_ipv6(net);
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}
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static inline int fnhe_genid(struct net *net)
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{
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return atomic_read(&net->fnhe_genid);
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}
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static inline void fnhe_genid_bump(struct net *net)
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{
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atomic_inc(&net->fnhe_genid);
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}
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#endif /* __NET_NET_NAMESPACE_H */
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