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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-06-21 15:43:21 +02:00
Breno Leitao
f35422ed36
find_skb() is the netconsole-specific entry into the netpoll skb
pool: every other netpoll consumer (bonding, team, vlan, bridge,
macvlan, dsa) builds its own sk_buff and never touches the pool.
With netpoll_send_udp() (its only caller) now living in netconsole,
find_skb() can join it.
Move find_skb() into drivers/net/netconsole.c as a file-static
helper, drop EXPORT_SYMBOL_GPL(find_skb) and remove its prototype
from include/linux/netpoll.h. find_skb() drains TX completions via
netpoll_zap_completion_queue(), which is already exported in the
NETDEV_INTERNAL namespace, so netconsole picks up
MODULE_IMPORT_NS("NETDEV_INTERNAL") to consume it.
The skb pool's lifecycle (np->skb_pool, np->refill_wq, refill_skbs(),
refill_skbs_work_handler(), skb_pool_flush()) stays in netpoll: it
is initialised in __netpoll_setup() and torn down in
__netpoll_cleanup(), both of which remain netpoll's responsibility.
The refill work queued via schedule_work(&np->refill_wq) from the
moved find_skb() runs refill_skbs_work_handler() in netpoll without
any further plumbing.
This is pure code motion: the function body is unchanged and its
sole caller (netpoll_send_udp(), already moved by an earlier patch)
keeps invoking it the same way. Pre-existing concerns about
find_skb() running from NMI/printk context (zap_completion_queue()
re-entry, skb_pool spinlocks, GFP_ATOMIC allocation, fallback skb
sizing vs. MAX_SKB_SIZE, PREEMPT_RT semantics of __kfree_skb()) are
inherited as-is and are not addressed here; they predate this
series and are out of scope. Fixing them is left for follow-up
work.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260512-netconsole_split-v2-9-1191d14ad66d@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
122 lines
2.7 KiB
C
122 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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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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#include <linux/refcount.h>
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union inet_addr {
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__be32 ip;
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struct in6_addr in6;
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};
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struct netpoll {
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struct net_device *dev;
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netdevice_tracker dev_tracker;
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/*
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* Either dev_name or dev_mac can be used to specify the local
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* interface - dev_name is used if it is a nonempty string, else
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* dev_mac is used.
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*/
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char dev_name[IFNAMSIZ];
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u8 dev_mac[ETH_ALEN];
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const char *name;
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union inet_addr local_ip, remote_ip;
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bool ipv6;
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u16 local_port, remote_port;
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u8 remote_mac[ETH_ALEN];
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struct sk_buff_head skb_pool;
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struct work_struct refill_wq;
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};
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#define np_info(np, fmt, ...) \
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pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
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#define np_err(np, fmt, ...) \
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pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
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#define np_notice(np, fmt, ...) \
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pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
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struct netpoll_info {
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refcount_t refcnt;
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struct semaphore dev_lock;
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struct sk_buff_head txq;
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struct delayed_work tx_work;
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struct rcu_head rcu;
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};
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#ifdef CONFIG_NETPOLL
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void netpoll_poll_dev(struct net_device *dev);
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void netpoll_poll_disable(struct net_device *dev);
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void netpoll_poll_enable(struct net_device *dev);
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#else
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static inline void netpoll_poll_disable(struct net_device *dev) { return; }
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static inline void netpoll_poll_enable(struct net_device *dev) { return; }
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#endif
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int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
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int netpoll_setup(struct netpoll *np);
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void __netpoll_free(struct netpoll *np);
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void netpoll_cleanup(struct netpoll *np);
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void do_netpoll_cleanup(struct netpoll *np);
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netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
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void netpoll_zap_completion_queue(void);
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#ifdef CONFIG_NETPOLL
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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 && rcu_access_pointer(dev->npinfo)) {
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int owner = smp_processor_id();
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while (cmpxchg(&napi->poll_owner, -1, owner) != -1)
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cpu_relax();
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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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smp_store_release(&napi->poll_owner, -1);
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}
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static inline bool 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 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 bool netpoll_tx_running(struct net_device *dev)
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{
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return false;
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}
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#endif
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#endif
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