From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ 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@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
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 a5815be7c81c..8daf2e44595a 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -94,6 +94,44 @@ 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);
@@ -1177,6 +1215,9 @@ 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);
#ifdef CONFIG_NETLINK_MMAP
--
2.14.1