6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 07cc7b0b942bf55ef1a471470ecda8d2a6a6541f ]
Before commit addf9b90de22 ("net: rtnetlink: use rcu to free rtnl message handlers"), once rtnl_msg_handlers[protocol] was allocated, the following rtnl_register_module() for the same protocol never failed.
However, after the commit, rtnl_msg_handler[protocol][msgtype] needs to be allocated in each rtnl_register_module(), so each call could fail.
Many callers of rtnl_register_module() do not handle the returned error, and we need to add many error handlings.
To handle that easily, let's add wrapper functions for bulk registration of rtnetlink message handlers.
Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: Paolo Abeni pabeni@redhat.com Stable-dep-of: 78b7b991838a ("vxlan: Handle error of rtnl_register_module().") Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/rtnetlink.h | 17 +++++++++++++++++ net/core/rtnetlink.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+)
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index 6506221c5fe31..0bd400be3f8d9 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -27,6 +27,15 @@ static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype) return msgtype & RTNL_KIND_MASK; }
+struct rtnl_msg_handler { + struct module *owner; + int protocol; + int msgtype; + rtnl_doit_func doit; + rtnl_dumpit_func dumpit; + int flags; +}; + void rtnl_register(int protocol, int msgtype, rtnl_doit_func, rtnl_dumpit_func, unsigned int flags); int rtnl_register_module(struct module *owner, int protocol, int msgtype, @@ -34,6 +43,14 @@ int rtnl_register_module(struct module *owner, int protocol, int msgtype, int rtnl_unregister(int protocol, int msgtype); void rtnl_unregister_all(int protocol);
+int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n); +void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n); + +#define rtnl_register_many(handlers) \ + __rtnl_register_many(handlers, ARRAY_SIZE(handlers)) +#define rtnl_unregister_many(handlers) \ + __rtnl_unregister_many(handlers, ARRAY_SIZE(handlers)) + static inline int rtnl_msg_family(const struct nlmsghdr *nlh) { if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg)) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8573dad6d8171..ffa1334cddf44 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -389,6 +389,35 @@ void rtnl_unregister_all(int protocol) } EXPORT_SYMBOL_GPL(rtnl_unregister_all);
+int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n) +{ + const struct rtnl_msg_handler *handler; + int i, err; + + for (i = 0, handler = handlers; i < n; i++, handler++) { + err = rtnl_register_internal(handler->owner, handler->protocol, + handler->msgtype, handler->doit, + handler->dumpit, handler->flags); + if (err) { + __rtnl_unregister_many(handlers, i); + break; + } + } + + return err; +} +EXPORT_SYMBOL_GPL(__rtnl_register_many); + +void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n) +{ + const struct rtnl_msg_handler *handler; + int i; + + for (i = n - 1, handler = handlers + n - 1; i >= 0; i--, handler--) + rtnl_unregister(handler->protocol, handler->msgtype); +} +EXPORT_SYMBOL_GPL(__rtnl_unregister_many); + static LIST_HEAD(link_ops);
static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)