From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- net/openvswitch/vport.c | 510 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 510 insertions(+) create mode 100644 net/openvswitch/vport.c (limited to 'net/openvswitch/vport.c') diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c new file mode 100644 index 000000000..083f7a8d9 --- /dev/null +++ b/net/openvswitch/vport.c @@ -0,0 +1,510 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2007-2014 Nicira, Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "datapath.h" +#include "vport.h" +#include "vport-internal_dev.h" + +static LIST_HEAD(vport_ops_list); + +/* Protected by RCU read lock for reading, ovs_mutex for writing. */ +static struct hlist_head *dev_table; +#define VPORT_HASH_BUCKETS 1024 + +/** + * ovs_vport_init - initialize vport subsystem + * + * Called at module load time to initialize the vport subsystem. + */ +int ovs_vport_init(void) +{ + dev_table = kzalloc_objs(struct hlist_head, VPORT_HASH_BUCKETS); + if (!dev_table) + return -ENOMEM; + + return 0; +} + +/** + * ovs_vport_exit - shutdown vport subsystem + * + * Called at module exit time to shutdown the vport subsystem. + */ +void ovs_vport_exit(void) +{ + kfree(dev_table); +} + +static struct hlist_head *hash_bucket(const struct net *net, const char *name) +{ + unsigned int hash = jhash(name, strlen(name), (unsigned long) net); + return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)]; +} + +int ovs_vport_ops_register(struct vport_ops *ops) +{ + int err = -EEXIST; + struct vport_ops *o; + + ovs_lock(); + list_for_each_entry(o, &vport_ops_list, list) + if (ops->type == o->type) + goto errout; + + list_add_tail(&ops->list, &vport_ops_list); + err = 0; +errout: + ovs_unlock(); + return err; +} + +void ovs_vport_ops_unregister(struct vport_ops *ops) +{ + ovs_lock(); + list_del(&ops->list); + ovs_unlock(); +} + +/** + * ovs_vport_locate - find a port that has already been created + * + * @net: network namespace + * @name: name of port to find + * + * Must be called with ovs or RCU read lock. + */ +struct vport *ovs_vport_locate(const struct net *net, const char *name) +{ + struct hlist_head *bucket = hash_bucket(net, name); + struct vport *vport; + + hlist_for_each_entry_rcu(vport, bucket, hash_node, + lockdep_ovsl_is_held()) + if (!strcmp(name, ovs_vport_name(vport)) && + net_eq(ovs_dp_get_net(vport->dp), net)) + return vport; + + return NULL; +} + +/** + * ovs_vport_alloc - allocate and initialize new vport + * + * @priv_size: Size of private data area to allocate. + * @ops: vport device ops + * @parms: information about new vport. + * + * Allocate and initialize a new vport defined by @ops. The vport will contain + * a private data area of size @priv_size that can be accessed using + * vport_priv(). Some parameters of the vport will be initialized from @parms. + * @vports that are no longer needed should be released with + * vport_free(). + */ +struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops, + const struct vport_parms *parms) +{ + struct vport *vport; + size_t alloc_size; + int err; + + alloc_size = sizeof(struct vport); + if (priv_size) { + alloc_size = ALIGN(alloc_size, VPORT_ALIGN); + alloc_size += priv_size; + } + + vport = kzalloc(alloc_size, GFP_KERNEL); + if (!vport) + return ERR_PTR(-ENOMEM); + + vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu); + if (!vport->upcall_stats) { + err = -ENOMEM; + goto err_kfree_vport; + } + + vport->dp = parms->dp; + vport->port_no = parms->port_no; + vport->ops = ops; + INIT_HLIST_NODE(&vport->dp_hash_node); + + if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) { + err = -EINVAL; + goto err_free_percpu; + } + + return vport; + +err_free_percpu: + free_percpu(vport->upcall_stats); +err_kfree_vport: + kfree(vport); + return ERR_PTR(err); +} + +/** + * ovs_vport_free - uninitialize and free vport + * + * @vport: vport to free + * + * Frees a vport allocated with vport_alloc() when it is no longer needed. + * + * The caller must ensure that an RCU grace period has passed since the last + * time @vport was in a datapath. + */ +void ovs_vport_free(struct vport *vport) +{ + /* vport is freed from RCU callback or error path, Therefore + * it is safe to use raw dereference. + */ + kfree(rcu_dereference_raw(vport->upcall_portids)); + free_percpu(vport->upcall_stats); + kfree(vport); +} + +static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms) +{ + struct vport_ops *ops; + + list_for_each_entry(ops, &vport_ops_list, list) + if (ops->type == parms->type) + return ops; + + return NULL; +} + +/** + * ovs_vport_add - add vport device (for kernel callers) + * + * @parms: Information about new vport. + * + * Creates a new vport with the specified configuration (which is dependent on + * device type). ovs_mutex must be held. + */ +struct vport *ovs_vport_add(const struct vport_parms *parms) +{ + struct vport_ops *ops; + struct vport *vport; + + ops = ovs_vport_lookup(parms); + if (ops) { + struct hlist_head *bucket; + + vport = ops->create(parms); + if (IS_ERR(vport)) + return vport; + + bucket = hash_bucket(ovs_dp_get_net(vport->dp), + ovs_vport_name(vport)); + hlist_add_head_rcu(&vport->hash_node, bucket); + return vport; + } + + return ERR_PTR(-EAFNOSUPPORT); +} + +/** + * ovs_vport_del - delete existing vport device + * + * @vport: vport to delete. + * + * Detaches @vport from its datapath and destroys it. ovs_mutex must + * be held. + */ +void ovs_vport_del(struct vport *vport) +{ + hlist_del_rcu(&vport->hash_node); + vport->ops->destroy(vport); +} + +/** + * ovs_vport_get_stats - retrieve device stats + * + * @vport: vport from which to retrieve the stats + * @stats: location to store stats + * + * Retrieves transmit, receive, and error stats for the given device. + * + * Must be called with ovs_mutex or rcu_read_lock. + */ +void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats) +{ + const struct rtnl_link_stats64 *dev_stats; + struct rtnl_link_stats64 temp; + + dev_stats = dev_get_stats(vport->dev, &temp); + stats->rx_errors = dev_stats->rx_errors; + stats->tx_errors = dev_stats->tx_errors; + stats->tx_dropped = dev_stats->tx_dropped; + stats->rx_dropped = dev_stats->rx_dropped; + + stats->rx_bytes = dev_stats->rx_bytes; + stats->rx_packets = dev_stats->rx_packets; + stats->tx_bytes = dev_stats->tx_bytes; + stats->tx_packets = dev_stats->tx_packets; +} + +/** + * ovs_vport_get_upcall_stats - retrieve upcall stats + * + * @vport: vport from which to retrieve the stats. + * @skb: sk_buff where upcall stats should be appended. + * + * Retrieves upcall stats for the given device. + * + * Must be called with ovs_mutex or rcu_read_lock. + */ +int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb) +{ + u64 tx_success = 0, tx_fail = 0; + struct nlattr *nla; + int i; + + for_each_possible_cpu(i) { + const struct vport_upcall_stats_percpu *stats; + u64 n_success, n_fail; + unsigned int start; + + stats = per_cpu_ptr(vport->upcall_stats, i); + do { + start = u64_stats_fetch_begin(&stats->syncp); + n_success = u64_stats_read(&stats->n_success); + n_fail = u64_stats_read(&stats->n_fail); + } while (u64_stats_fetch_retry(&stats->syncp, start)); + tx_success += n_success; + tx_fail += n_fail; + } + + nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS); + if (!nla) + return -EMSGSIZE; + + if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_SUCCESS, tx_success, + OVS_VPORT_ATTR_PAD)) { + nla_nest_cancel(skb, nla); + return -EMSGSIZE; + } + + if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_FAIL, tx_fail, + OVS_VPORT_ATTR_PAD)) { + nla_nest_cancel(skb, nla); + return -EMSGSIZE; + } + nla_nest_end(skb, nla); + + return 0; +} + +/** + * ovs_vport_set_upcall_portids - set upcall portids of @vport. + * + * @vport: vport to modify. + * @ids: new configuration, an array of port ids. + * + * Sets the vport's upcall_portids to @ids. + * + * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed + * as an array of U32. + * + * Must be called with ovs_mutex. + */ +int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids) +{ + struct vport_portids *old, *vport_portids; + + if (!nla_len(ids) || nla_len(ids) % sizeof(u32)) + return -EINVAL; + + if (nla_len(ids) / sizeof(u32) > nr_cpu_ids) + return -EINVAL; + + old = ovsl_dereference(vport->upcall_portids); + + vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids), + GFP_KERNEL); + if (!vport_portids) + return -ENOMEM; + + vport_portids->n_ids = nla_len(ids) / sizeof(u32); + vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids); + nla_memcpy(vport_portids->ids, ids, nla_len(ids)); + + rcu_assign_pointer(vport->upcall_portids, vport_portids); + + if (old) + kfree_rcu(old, rcu); + return 0; +} + +/** + * ovs_vport_get_upcall_portids - get the upcall_portids of @vport. + * + * @vport: vport from which to retrieve the portids. + * @skb: sk_buff where portids should be appended. + * + * Retrieves the configuration of the given vport, appending the + * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall + * portids to @skb. + * + * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room. + * If an error occurs, @skb is left unmodified. Must be called with + * ovs_mutex or rcu_read_lock. + */ +int ovs_vport_get_upcall_portids(const struct vport *vport, + struct sk_buff *skb) +{ + struct vport_portids *ids; + + ids = rcu_dereference_ovsl(vport->upcall_portids); + + if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS) + return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID, + ids->n_ids * sizeof(u32), (void *)ids->ids); + else + return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]); +} + +/** + * ovs_vport_find_upcall_portid - find the upcall portid to send upcall. + * + * @vport: vport from which the missed packet is received. + * @skb: skb that the missed packet was received. + * + * Uses the skb_get_hash() to select the upcall portid to send the + * upcall. + * + * Returns the portid of the target socket. Must be called with rcu_read_lock. + */ +u32 ovs_vport_find_upcall_portid(const struct vport *vport, + struct sk_buff *skb) +{ + struct vport_portids *ids; + u32 ids_index; + u32 hash; + + ids = rcu_dereference(vport->upcall_portids); + + /* If there is only one portid, select it in the fast-path. */ + if (ids->n_ids == 1) + return ids->ids[0]; + + hash = skb_get_hash(skb); + ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids); + return ids->ids[ids_index]; +} + +/** + * ovs_vport_receive - pass up received packet to the datapath for processing + * + * @vport: vport that received the packet + * @skb: skb that was received + * @tun_info: tunnel (if any) that carried packet + * + * Must be called with rcu_read_lock. The packet cannot be shared and + * skb->data should point to the Ethernet header. + */ +int ovs_vport_receive(struct vport *vport, struct sk_buff *skb, + const struct ip_tunnel_info *tun_info) +{ + struct sw_flow_key key; + int error; + + OVS_CB(skb)->input_vport = vport; + OVS_CB(skb)->mru = 0; + OVS_CB(skb)->cutlen = U32_MAX; + OVS_CB(skb)->probability = 0; + OVS_CB(skb)->upcall_pid = 0; + if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) { + u32 mark; + + mark = skb->mark; + skb_scrub_packet(skb, true); + skb->mark = mark; + tun_info = NULL; + } + + /* Extract flow from 'skb' into 'key'. */ + error = ovs_flow_key_extract(tun_info, skb, &key); + if (unlikely(error)) { + kfree_skb(skb); + return error; + } + ovs_dp_process_packet(skb, &key); + return 0; +} + +static int packet_length(const struct sk_buff *skb, + struct net_device *dev) +{ + int length = skb->len - dev->hard_header_len; + + if (!skb_vlan_tag_present(skb) && + eth_type_vlan(skb->protocol)) + length -= VLAN_HLEN; + + /* Don't subtract for multiple VLAN tags. Most (all?) drivers allow + * (ETH_LEN + VLAN_HLEN) in addition to the mtu value, but almost none + * account for 802.1ad. e.g. is_skb_forwardable(). + */ + + return length > 0 ? length : 0; +} + +void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto) +{ + int mtu = vport->dev->mtu; + + switch (vport->dev->type) { + case ARPHRD_NONE: + if (mac_proto == MAC_PROTO_ETHERNET) { + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + skb->protocol = htons(ETH_P_TEB); + } else if (mac_proto != MAC_PROTO_NONE) { + WARN_ON_ONCE(1); + goto drop; + } + break; + case ARPHRD_ETHER: + if (mac_proto != MAC_PROTO_ETHERNET) + goto drop; + break; + default: + goto drop; + } + + if (unlikely(packet_length(skb, vport->dev) > mtu && + !skb_is_gso(skb))) { + vport->dev->stats.tx_errors++; + if (vport->dev->flags & IFF_UP) + net_warn_ratelimited("%s: dropped over-mtu packet: " + "%d > %d\n", vport->dev->name, + packet_length(skb, vport->dev), + mtu); + goto drop; + } + + skb->dev = vport->dev; + skb_clear_tstamp(skb); + vport->ops->send(skb); + return; + +drop: + kfree_skb(skb); +} -- cgit v1.3.1