From bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 20 Sep 2026 08:15:23 -0700 Subject: Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork() --- include/net/netns/generic.h | 52 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 include/net/netns/generic.h (limited to 'include/net/netns/generic.h') diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h new file mode 100644 index 000000000..00c399ede --- /dev/null +++ b/include/net/netns/generic.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * generic net pointers + */ + +#ifndef __NET_GENERIC_H__ +#define __NET_GENERIC_H__ + +#include +#include +#include + +/* + * Generic net pointers are to be used by modules to put some private + * stuff on the struct net without explicit struct net modification + * + * The rules are simple: + * 1. set pernet_operations->id. After register_pernet_device you + * will have the id of your private pointer. + * 2. set pernet_operations->size to have the code allocate and free + * a private structure pointed to from struct net. + * 3. do not change this pointer while the net is alive; + * 4. do not try to have any private reference on the net_generic object. + * + * After accomplishing all of the above, the private pointer can be + * accessed with the net_generic() call. + */ + +struct net_generic { + union { + struct { + unsigned int len; + struct rcu_head rcu; + } s; + + DECLARE_FLEX_ARRAY(void *, ptr); + }; +}; + +static inline void *net_generic(const struct net *net, unsigned int id) +{ + struct net_generic *ng; + void *ptr; + + rcu_read_lock(); + ng = rcu_dereference(net->gen); + ptr = ng->ptr[id]; + rcu_read_unlock(); + + return ptr; +} +#endif -- cgit v1.3.1