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/nsh/Kconfig | 10 ++++ net/nsh/Makefile | 2 + net/nsh/nsh.c | 153 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 165 insertions(+) create mode 100644 net/nsh/Kconfig create mode 100644 net/nsh/Makefile create mode 100644 net/nsh/nsh.c (limited to 'net/nsh') diff --git a/net/nsh/Kconfig b/net/nsh/Kconfig new file mode 100644 index 000000000..84f2a2823 --- /dev/null +++ b/net/nsh/Kconfig @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig NET_NSH + tristate "Network Service Header (NSH) protocol" + default n + help + Network Service Header is an implementation of Service Function + Chaining (RFC 7665). The current implementation in Linux supports + only MD type 1 and only with the openvswitch module. + + If unsure, say N. diff --git a/net/nsh/Makefile b/net/nsh/Makefile new file mode 100644 index 000000000..de34a615a --- /dev/null +++ b/net/nsh/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_NET_NSH) += nsh.o diff --git a/net/nsh/nsh.c b/net/nsh/nsh.c new file mode 100644 index 000000000..bfb775806 --- /dev/null +++ b/net/nsh/nsh.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Network Service Header + * + * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc + */ + +#include +#include +#include +#include +#include +#include + +int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh) +{ + struct nshhdr *nh; + size_t length = nsh_hdr_len(pushed_nh); + u8 next_proto; + + if (skb->mac_len) { + next_proto = TUN_P_ETHERNET; + } else { + next_proto = tun_p_from_eth_p(skb->protocol); + if (!next_proto) + return -EAFNOSUPPORT; + } + + /* Add the NSH header */ + if (skb_cow_head(skb, length) < 0) + return -ENOMEM; + + skb_push(skb, length); + nh = (struct nshhdr *)(skb->data); + memcpy(nh, pushed_nh, length); + nh->np = next_proto; + skb_postpush_rcsum(skb, nh, length); + + skb->protocol = htons(ETH_P_NSH); + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + + return 0; +} +EXPORT_SYMBOL_GPL(nsh_push); + +int nsh_pop(struct sk_buff *skb) +{ + struct nshhdr *nh; + size_t length; + __be16 inner_proto; + + if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN)) + return -ENOMEM; + nh = (struct nshhdr *)(skb->data); + length = nsh_hdr_len(nh); + if (length < NSH_BASE_HDR_LEN) + return -EINVAL; + inner_proto = tun_p_to_eth_p(nh->np); + if (!pskb_may_pull(skb, length)) + return -ENOMEM; + + if (!inner_proto) + return -EAFNOSUPPORT; + + skb_pull_rcsum(skb, length); + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_reset_mac_len(skb); + skb->protocol = inner_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(nsh_pop); + +static struct sk_buff *nsh_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + unsigned int outer_hlen, mac_len, nsh_len; + struct sk_buff *segs = ERR_PTR(-EINVAL); + u16 mac_offset = skb->mac_header; + __be16 outer_proto, proto; + + skb_reset_network_header(skb); + + outer_proto = skb->protocol; + outer_hlen = skb_mac_header_len(skb); + mac_len = skb->mac_len; + + if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN))) + goto out; + nsh_len = nsh_hdr_len(nsh_hdr(skb)); + if (nsh_len < NSH_BASE_HDR_LEN) + goto out; + if (unlikely(!pskb_may_pull(skb, nsh_len))) + goto out; + + proto = tun_p_to_eth_p(nsh_hdr(skb)->np); + if (!proto) + goto out; + + __skb_pull(skb, nsh_len); + + skb_reset_mac_header(skb); + skb->mac_len = proto == htons(ETH_P_TEB) ? ETH_HLEN : 0; + skb->protocol = proto; + + features &= NETIF_F_SG; + segs = skb_mac_gso_segment(skb, features); + if (IS_ERR_OR_NULL(segs)) { + skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len, + mac_offset, mac_len); + goto out; + } + + for (skb = segs; skb; skb = skb->next) { + skb->protocol = outer_proto; + __skb_push(skb, nsh_len + outer_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, outer_hlen); + skb->mac_len = mac_len; + } + +out: + return segs; +} + +static struct packet_offload nsh_packet_offload __read_mostly = { + .type = htons(ETH_P_NSH), + .priority = 15, + .callbacks = { + .gso_segment = nsh_gso_segment, + }, +}; + +static int __init nsh_init_module(void) +{ + dev_add_offload(&nsh_packet_offload); + return 0; +} + +static void __exit nsh_cleanup_module(void) +{ + dev_remove_offload(&nsh_packet_offload); +} + +module_init(nsh_init_module); +module_exit(nsh_cleanup_module); + +MODULE_AUTHOR("Jiri Benc "); +MODULE_DESCRIPTION("NSH protocol"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1