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Message-ID: <20251219140408.2300163-1-metze@samba.org>
Date: Fri, 19 Dec 2025 15:04:08 +0100
From: Stefan Metzmacher <metze@...ba.org>
To: linux-rdma@...r.kernel.org
Cc: metze@...ba.org,
Zhu Yanjun <zyjzyj2000@...il.com>,
Jason Gunthorpe <jgg@...pe.ca>,
Leon Romanovsky <leon@...nel.org>,
Shinichiro Kawasaki <shinichiro.kawasaki@....com>,
netdev@...r.kernel.org,
linux-cifs@...r.kernel.org
Subject: [PATCH] RDMA/rxe: let rxe_reclassify_recv_socket() call sk_owner_put()
On kernels build with CONFIG_PROVE_LOCKING, CONFIG_MODULES
and CONFIG_DEBUG_LOCK_ALLOC 'rmmod rdma_rxe' is no longer
possible.
For the global recv sockets rxe_net_exit() is where we
call rxe_release_udp_tunnel-> udp_tunnel_sock_release(),
which means the sockets are destroyed before 'rmmod rdma_rxe'
finishes, so there's no need to protect against
rxe_recv_slock_key and rxe_recv_sk_key disappearing
while the sockets are still alive.
Fixes: 80a85a771deb ("RDMA/rxe: reclassify sockets in order to avoid false positives from lockdep")
Cc: Zhu Yanjun <zyjzyj2000@...il.com>
Cc: Jason Gunthorpe <jgg@...pe.ca>
Cc: Leon Romanovsky <leon@...nel.org>
Cc: Shinichiro Kawasaki <shinichiro.kawasaki@....com>
Cc: linux-rdma@...r.kernel.org
Cc: netdev@...r.kernel.org
Cc: linux-cifs@...r.kernel.org
Signed-off-by: Stefan Metzmacher <metze@...ba.org>
---
drivers/infiniband/sw/rxe/rxe_net.c | 32 +++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index 0195d361e5e3..0bd0902b11f7 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -64,7 +64,39 @@ static inline void rxe_reclassify_recv_socket(struct socket *sock)
break;
default:
WARN_ON_ONCE(1);
+ return;
}
+ /*
+ * sock_lock_init_class_and_name() calls
+ * sk_owner_set(sk, THIS_MODULE); in order
+ * to make sure the referenced global
+ * variables rxe_recv_slock_key and
+ * rxe_recv_sk_key are not removed
+ * before the socket is closed.
+ *
+ * However this prevents rxe_net_exit()
+ * from being called and 'rmmod rdma_rxe'
+ * is refused because of the references.
+ *
+ * For the global sockets in recv_sockets,
+ * we are sure that rxe_net_exit() will call
+ * rxe_release_udp_tunnel -> udp_tunnel_sock_release.
+ *
+ * So we don't need the additional reference to
+ * our own (THIS_MODULE).
+ */
+ sk_owner_put(sk);
+ /*
+ * We also call sk_owner_clear() otherwise
+ * sk_owner_put(sk) in sk_prot_free will
+ * fail, which is called via
+ * sk_free -> __sk_free -> sk_destruct
+ * and sk_destruct calls __sk_destruct
+ * directly or via call_rcu()
+ * so sk_prot_free() might be called
+ * after rxe_net_exit().
+ */
+ sk_owner_clear(sk);
#endif /* CONFIG_DEBUG_LOCK_ALLOC */
}
--
2.43.0
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