From: Herbert Xu herbert@gondor.apana.org.au
[ Upstream commit 8a0f5ccfb33b0b8b51de65b7b3bf342ba10b4fb6 ]
On Tue, Mar 14, 2017 at 10:44:10AM +0100, Dmitry Vyukov wrote:
Yes, please. Disregarding some reports is not a good way long term.
Please try this patch.
---8<--- Subject: netlink: Annotate nlk cb_mutex by protocol
Currently all occurences of nlk->cb_mutex are annotated by lockdep as a single class. This causes a false lcokdep cycle involving genl and crypto_user.
This patch fixes it by dividing cb_mutex into individual classes based on the netlink protocol. As genl and crypto_user do not use the same netlink protocol this breaks the false dependency loop.
Reported-by: Dmitry Vyukov dvyukov@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com --- net/netlink/af_netlink.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index a87afc4f3c91..5fabe68e20dd 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -96,6 +96,44 @@ EXPORT_SYMBOL_GPL(nl_table);
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; + +static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { + "nlk_cb_mutex-ROUTE", + "nlk_cb_mutex-1", + "nlk_cb_mutex-USERSOCK", + "nlk_cb_mutex-FIREWALL", + "nlk_cb_mutex-SOCK_DIAG", + "nlk_cb_mutex-NFLOG", + "nlk_cb_mutex-XFRM", + "nlk_cb_mutex-SELINUX", + "nlk_cb_mutex-ISCSI", + "nlk_cb_mutex-AUDIT", + "nlk_cb_mutex-FIB_LOOKUP", + "nlk_cb_mutex-CONNECTOR", + "nlk_cb_mutex-NETFILTER", + "nlk_cb_mutex-IP6_FW", + "nlk_cb_mutex-DNRTMSG", + "nlk_cb_mutex-KOBJECT_UEVENT", + "nlk_cb_mutex-GENERIC", + "nlk_cb_mutex-17", + "nlk_cb_mutex-SCSITRANSPORT", + "nlk_cb_mutex-ECRYPTFS", + "nlk_cb_mutex-RDMA", + "nlk_cb_mutex-CRYPTO", + "nlk_cb_mutex-SMC", + "nlk_cb_mutex-23", + "nlk_cb_mutex-24", + "nlk_cb_mutex-25", + "nlk_cb_mutex-26", + "nlk_cb_mutex-27", + "nlk_cb_mutex-28", + "nlk_cb_mutex-29", + "nlk_cb_mutex-30", + "nlk_cb_mutex-31", + "nlk_cb_mutex-MAX_LINKS" +}; + static int netlink_dump(struct sock *sk); static void netlink_skb_destructor(struct sk_buff *skb);
@@ -585,6 +623,9 @@ static int __netlink_create(struct net *net, struct socket *sock, } else { nlk->cb_mutex = &nlk->cb_def_mutex; mutex_init(nlk->cb_mutex); + lockdep_set_class_and_name(nlk->cb_mutex, + nlk_cb_mutex_keys + protocol, + nlk_cb_mutex_key_strings[protocol]); } init_waitqueue_head(&nlk->wait);