diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-07-31 13:07:17 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-08-03 22:38:44 +0100 |
| commit | 768e4bb6a75e3c6a034df7c67edac20bd222857e (patch) | |
| tree | dbf45faf8087ca30a2d44701ecd227122d8f1ec7 | |
| parent | 1ad001347fb1ca1f036144b42a6f1df6615e4104 (diff) | |
net: Don't register pernet_operations if only one of id or size is specified.
We can allocate per-netns memory for struct pernet_operations by specifying
id and size.
register_pernet_operations() assigns an id to pernet_operations and later
ops_init() allocates the specified size of memory as net->gen->ptr[id].
If id is missing, no memory is allocated. If size is not specified,
pernet_operations just wastes an entry of net->gen->ptr[] for every netns.
net_generic is available only when both id and size are specified, so let's
ensure that.
While we are at it, we add const to both fields.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/net_namespace.h | 4 | ||||
| -rw-r--r-- | net/core/net_namespace.c | 12 |
2 files changed, 10 insertions, 6 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 20c34bd7a077..e67b483cc8bb 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -451,8 +451,8 @@ struct pernet_operations { /* Following method is called with RTNL held. */ void (*exit_batch_rtnl)(struct list_head *net_exit_list, struct list_head *dev_kill_list); - unsigned int *id; - size_t size; + unsigned int * const id; + const size_t size; }; /* diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 6a823ba906c6..1cd87df13f39 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -125,7 +125,7 @@ static int ops_init(const struct pernet_operations *ops, struct net *net) int err = -ENOMEM; void *data = NULL; - if (ops->id && ops->size) { + if (ops->id) { data = kzalloc(ops->size, GFP_KERNEL); if (!data) goto out; @@ -140,7 +140,7 @@ static int ops_init(const struct pernet_operations *ops, struct net *net) if (!err) return 0; - if (ops->id && ops->size) { + if (ops->id) { ng = rcu_dereference_protected(net->gen, lockdep_is_held(&pernet_ops_rwsem)); ng->ptr[*ops->id] = NULL; @@ -182,7 +182,8 @@ static void ops_free_list(const struct pernet_operations *ops, struct list_head *net_exit_list) { struct net *net; - if (ops->size && ops->id) { + + if (ops->id) { list_for_each_entry(net, net_exit_list, exit_list) kfree(net_generic(net, *ops->id)); } @@ -1244,7 +1245,7 @@ static int __register_pernet_operations(struct list_head *list, LIST_HEAD(net_exit_list); list_add_tail(&ops->list, list); - if (ops->init || (ops->id && ops->size)) { + if (ops->init || ops->id) { /* We held write locked pernet_ops_rwsem, and parallel * setup_net() and cleanup_net() are not possible. */ @@ -1310,6 +1311,9 @@ static int register_pernet_operations(struct list_head *list, { int error; + if (WARN_ON(!!ops->id ^ !!ops->size)) + return -EINVAL; + if (ops->id) { error = ida_alloc_min(&net_generic_ids, MIN_PERNET_OPS_ID, GFP_KERNEL); |