From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/net/ifb.c | 458 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 458 insertions(+) create mode 100644 drivers/net/ifb.c (limited to 'drivers/net/ifb.c') diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c new file mode 100644 index 000000000..43aa1bfd4 --- /dev/null +++ b/drivers/net/ifb.c @@ -0,0 +1,458 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* drivers/net/ifb.c: + + The purpose of this driver is to provide a device that allows + for sharing of resources: + + 1) qdiscs/policies that are per device as opposed to system wide. + ifb allows for a device which can be redirected to thus providing + an impression of sharing. + + 2) Allows for queueing incoming traffic for shaping instead of + dropping. + + The original concept is based on what is known as the IMQ + driver initially written by Martin Devera, later rewritten + by Patrick McHardy and then maintained by Andre Correa. + + You need the tc action mirror or redirect to feed this device + packets. + + + Authors: Jamal Hadi Salim (2005) + +*/ + + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TX_Q_LIMIT 32 + +struct ifb_q_stats { + u64_stats_t packets; + u64_stats_t bytes; + struct u64_stats_sync sync; +}; + +struct ifb_q_private { + struct net_device *dev; + struct tasklet_struct ifb_tasklet; + int tasklet_pending; + int txqnum; + struct sk_buff_head rq; + struct sk_buff_head tq; + struct ifb_q_stats rx_stats; + struct ifb_q_stats tx_stats; +} ____cacheline_aligned_in_smp; + +struct ifb_dev_private { + struct ifb_q_private *tx_private; +}; + +/* For ethtools stats. */ +struct ifb_q_stats_desc { + char desc[ETH_GSTRING_LEN]; + size_t offset; +}; + +#define IFB_Q_STAT(m) offsetof(struct ifb_q_stats, m) + +static const struct ifb_q_stats_desc ifb_q_stats_desc[] = { + { "packets", IFB_Q_STAT(packets) }, + { "bytes", IFB_Q_STAT(bytes) }, +}; + +#define IFB_Q_STATS_LEN ARRAY_SIZE(ifb_q_stats_desc) + +static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev); +static int ifb_open(struct net_device *dev); +static int ifb_close(struct net_device *dev); + +static void ifb_update_q_stats(struct ifb_q_stats *stats, int len) +{ + u64_stats_update_begin(&stats->sync); + u64_stats_inc(&stats->packets); + u64_stats_add(&stats->bytes, len); + u64_stats_update_end(&stats->sync); +} + +static void ifb_ri_tasklet(struct tasklet_struct *t) +{ + struct ifb_q_private *txp = from_tasklet(txp, t, ifb_tasklet); + struct netdev_queue *txq; + struct sk_buff *skb; + + txq = netdev_get_tx_queue(txp->dev, txp->txqnum); + skb = skb_peek(&txp->tq); + if (!skb) { + if (!__netif_tx_trylock(txq)) + goto resched; + skb_queue_splice_tail_init(&txp->rq, &txp->tq); + __netif_tx_unlock(txq); + } + + while ((skb = __skb_dequeue(&txp->tq)) != NULL) { + /* Skip tc and netfilter to prevent redirection loop. */ + skb->redirected = 0; +#ifdef CONFIG_NET_CLS_ACT + skb->tc_skip_classify = 1; +#endif + nf_skip_egress(skb, true); + + ifb_update_q_stats(&txp->tx_stats, skb->len); + + rcu_read_lock(); + skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif); + if (!skb->dev) { + rcu_read_unlock(); + dev_kfree_skb(skb); + txp->dev->stats.tx_dropped++; + if (skb_queue_len(&txp->tq) != 0) + goto resched; + break; + } + rcu_read_unlock(); + skb->skb_iif = txp->dev->ifindex; + + if (!skb->from_ingress) { + dev_queue_xmit(skb); + } else { + skb_pull_rcsum(skb, skb->mac_len); + netif_receive_skb(skb); + } + } + + if (__netif_tx_trylock(txq)) { + skb = skb_peek(&txp->rq); + if (!skb) { + txp->tasklet_pending = 0; + if (netif_tx_queue_stopped(txq)) + netif_tx_wake_queue(txq); + } else { + __netif_tx_unlock(txq); + goto resched; + } + __netif_tx_unlock(txq); + } else { +resched: + txp->tasklet_pending = 1; + tasklet_schedule(&txp->ifb_tasklet); + } + +} + +static void ifb_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + struct ifb_dev_private *dp = netdev_priv(dev); + struct ifb_q_private *txp = dp->tx_private; + unsigned int start; + u64 packets, bytes; + int i; + + for (i = 0; i < dev->num_tx_queues; i++,txp++) { + do { + start = u64_stats_fetch_begin(&txp->rx_stats.sync); + packets = u64_stats_read(&txp->rx_stats.packets); + bytes = u64_stats_read(&txp->rx_stats.bytes); + } while (u64_stats_fetch_retry(&txp->rx_stats.sync, start)); + stats->rx_packets += packets; + stats->rx_bytes += bytes; + + do { + start = u64_stats_fetch_begin(&txp->tx_stats.sync); + packets = u64_stats_read(&txp->tx_stats.packets); + bytes = u64_stats_read(&txp->tx_stats.bytes); + } while (u64_stats_fetch_retry(&txp->tx_stats.sync, start)); + stats->tx_packets += packets; + stats->tx_bytes += bytes; + } + stats->rx_dropped = dev->stats.rx_dropped; + stats->tx_dropped = dev->stats.tx_dropped; +} + +static int ifb_dev_init(struct net_device *dev) +{ + struct ifb_dev_private *dp = netdev_priv(dev); + struct ifb_q_private *txp; + int i; + + txp = kzalloc_objs(*txp, dev->num_tx_queues); + if (!txp) + return -ENOMEM; + dp->tx_private = txp; + for (i = 0; i < dev->num_tx_queues; i++,txp++) { + txp->txqnum = i; + txp->dev = dev; + __skb_queue_head_init(&txp->rq); + __skb_queue_head_init(&txp->tq); + u64_stats_init(&txp->rx_stats.sync); + u64_stats_init(&txp->tx_stats.sync); + tasklet_setup(&txp->ifb_tasklet, ifb_ri_tasklet); + netif_tx_start_queue(netdev_get_tx_queue(dev, i)); + } + return 0; +} + +static void ifb_get_strings(struct net_device *dev, u32 stringset, u8 *buf) +{ + u8 *p = buf; + int i, j; + + switch (stringset) { + case ETH_SS_STATS: + for (i = 0; i < dev->num_tx_queues; i++) + for (j = 0; j < IFB_Q_STATS_LEN; j++) + ethtool_sprintf(&p, "rx_queue_%u_%.18s", + i, ifb_q_stats_desc[j].desc); + + for (i = 0; i < dev->num_tx_queues; i++) + for (j = 0; j < IFB_Q_STATS_LEN; j++) + ethtool_sprintf(&p, "tx_queue_%u_%.18s", + i, ifb_q_stats_desc[j].desc); + + break; + } +} + +static int ifb_get_sset_count(struct net_device *dev, int sset) +{ + switch (sset) { + case ETH_SS_STATS: + return IFB_Q_STATS_LEN * dev->num_tx_queues * 2; + default: + return -EOPNOTSUPP; + } +} + +static void ifb_fill_stats_data(u64 **data, + struct ifb_q_stats *q_stats) +{ + void *stats_base = (void *)q_stats; + unsigned int start; + size_t offset; + int j; + + do { + start = u64_stats_fetch_begin(&q_stats->sync); + for (j = 0; j < IFB_Q_STATS_LEN; j++) { + offset = ifb_q_stats_desc[j].offset; + (*data)[j] = u64_stats_read((u64_stats_t *)(stats_base + offset)); + } + } while (u64_stats_fetch_retry(&q_stats->sync, start)); + + *data += IFB_Q_STATS_LEN; +} + +static void ifb_get_ethtool_stats(struct net_device *dev, + struct ethtool_stats *stats, u64 *data) +{ + struct ifb_dev_private *dp = netdev_priv(dev); + struct ifb_q_private *txp; + int i; + + for (i = 0; i < dev->num_tx_queues; i++) { + txp = dp->tx_private + i; + ifb_fill_stats_data(&data, &txp->rx_stats); + } + + for (i = 0; i < dev->num_tx_queues; i++) { + txp = dp->tx_private + i; + ifb_fill_stats_data(&data, &txp->tx_stats); + } +} + +static const struct net_device_ops ifb_netdev_ops = { + .ndo_open = ifb_open, + .ndo_stop = ifb_close, + .ndo_get_stats64 = ifb_stats64, + .ndo_start_xmit = ifb_xmit, + .ndo_validate_addr = eth_validate_addr, + .ndo_init = ifb_dev_init, +}; + +static const struct ethtool_ops ifb_ethtool_ops = { + .get_strings = ifb_get_strings, + .get_sset_count = ifb_get_sset_count, + .get_ethtool_stats = ifb_get_ethtool_stats, +}; + +#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \ + NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \ + NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \ + NETIF_F_HW_VLAN_STAG_TX) + +static void ifb_dev_free(struct net_device *dev) +{ + struct ifb_dev_private *dp = netdev_priv(dev); + struct ifb_q_private *txp = dp->tx_private; + int i; + + for (i = 0; i < dev->num_tx_queues; i++,txp++) { + tasklet_kill(&txp->ifb_tasklet); + __skb_queue_purge(&txp->rq); + __skb_queue_purge(&txp->tq); + } + kfree(dp->tx_private); +} + +static void ifb_setup(struct net_device *dev) +{ + /* Initialize the device structure. */ + dev->netdev_ops = &ifb_netdev_ops; + dev->ethtool_ops = &ifb_ethtool_ops; + + /* Fill in device structure with ethernet-generic values. */ + ether_setup(dev); + dev->tx_queue_len = TX_Q_LIMIT; + + dev->features |= IFB_FEATURES; + dev->hw_features |= dev->features; + dev->hw_enc_features |= dev->features; + dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_STAG_TX); + + dev->flags |= IFF_NOARP; + dev->flags &= ~IFF_MULTICAST; + dev->priv_flags &= ~IFF_TX_SKB_SHARING; + netif_keep_dst(dev); + eth_hw_addr_random(dev); + dev->needs_free_netdev = true; + dev->priv_destructor = ifb_dev_free; + + dev->min_mtu = 0; + dev->max_mtu = 0; + netif_set_tso_max_size(dev, GSO_MAX_SIZE); +} + +static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ifb_dev_private *dp = netdev_priv(dev); + struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb); + + ifb_update_q_stats(&txp->rx_stats, skb->len); + + if (!skb->redirected || !skb->skb_iif) { + dev_kfree_skb(skb); + dev->stats.rx_dropped++; + return NETDEV_TX_OK; + } + + if (skb_queue_len(&txp->rq) >= dev->tx_queue_len) + netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum)); + + __skb_queue_tail(&txp->rq, skb); + if (!txp->tasklet_pending) { + txp->tasklet_pending = 1; + tasklet_schedule(&txp->ifb_tasklet); + } + + return NETDEV_TX_OK; +} + +static int ifb_close(struct net_device *dev) +{ + netif_tx_stop_all_queues(dev); + return 0; +} + +static int ifb_open(struct net_device *dev) +{ + netif_tx_start_all_queues(dev); + return 0; +} + +static int ifb_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + if (tb[IFLA_ADDRESS]) { + if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) + return -EINVAL; + if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) + return -EADDRNOTAVAIL; + } + return 0; +} + +static struct rtnl_link_ops ifb_link_ops __read_mostly = { + .kind = "ifb", + .priv_size = sizeof(struct ifb_dev_private), + .setup = ifb_setup, + .validate = ifb_validate, +}; + +/* Number of ifb devices to be set up by this module. + * Note that these legacy devices have one queue. + * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb + */ +static int numifbs = 2; +module_param(numifbs, int, 0); +MODULE_PARM_DESC(numifbs, "Number of ifb devices"); + +static int __init ifb_init_one(int index) +{ + struct net_device *dev_ifb; + int err; + + dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d", + NET_NAME_UNKNOWN, ifb_setup); + + if (!dev_ifb) + return -ENOMEM; + + dev_ifb->rtnl_link_ops = &ifb_link_ops; + err = register_netdevice(dev_ifb); + if (err < 0) + goto err; + + return 0; + +err: + free_netdev(dev_ifb); + return err; +} + +static int __init ifb_init_module(void) +{ + int i, err; + + err = rtnl_link_register(&ifb_link_ops); + if (err < 0) + return err; + + rtnl_net_lock(&init_net); + + for (i = 0; i < numifbs && !err; i++) { + err = ifb_init_one(i); + cond_resched(); + } + + rtnl_net_unlock(&init_net); + + if (err) + rtnl_link_unregister(&ifb_link_ops); + + return err; +} + +static void __exit ifb_cleanup_module(void) +{ + rtnl_link_unregister(&ifb_link_ops); +} + +module_init(ifb_init_module); +module_exit(ifb_cleanup_module); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Intermediate Functional Block (ifb) netdevice driver for sharing of resources and ingress packet queuing"); +MODULE_AUTHOR("Jamal Hadi Salim"); +MODULE_ALIAS_RTNL_LINK("ifb"); -- cgit v1.3.1