From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ido Schimmel <idosch@nvidia.com>,
David Ahern <dsahern@gmail.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.8 07/16] ipv4: Silence suspicious RCU usage warning
Date: Fri, 11 Sep 2020 14:47:24 +0200 [thread overview]
Message-ID: <20200911122459.944382043@linuxfoundation.org> (raw)
In-Reply-To: <20200911122459.585735377@linuxfoundation.org>
From: Ido Schimmel <idosch@nvidia.com>
[ Upstream commit 7f6f32bb7d3355cd78ebf1dece9a6ea7a0ca8158 ]
fib_info_notify_update() is always called with RTNL held, but not from
an RCU read-side critical section. This leads to the following warning
[1] when the FIB table list is traversed with
hlist_for_each_entry_rcu(), but without a proper lockdep expression.
Since modification of the list is protected by RTNL, silence the warning
by adding a lockdep expression which verifies RTNL is held.
[1]
=============================
WARNING: suspicious RCU usage
5.9.0-rc1-custom-14233-g2f26e122d62f #129 Not tainted
-----------------------------
net/ipv4/fib_trie.c:2124 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/834:
#0: ffffffff85a3b6b0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0
stack backtrace:
CPU: 0 PID: 834 Comm: ip Not tainted 5.9.0-rc1-custom-14233-g2f26e122d62f #129
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack+0x100/0x184
lockdep_rcu_suspicious+0x143/0x14d
fib_info_notify_update+0x8d1/0xa60
__nexthop_replace_notify+0xd2/0x290
rtm_new_nexthop+0x35e2/0x5946
rtnetlink_rcv_msg+0x4f7/0xbd0
netlink_rcv_skb+0x17a/0x480
rtnetlink_rcv+0x22/0x30
netlink_unicast+0x5ae/0x890
netlink_sendmsg+0x98a/0xf40
____sys_sendmsg+0x879/0xa00
___sys_sendmsg+0x122/0x190
__sys_sendmsg+0x103/0x1d0
__x64_sys_sendmsg+0x7d/0xb0
do_syscall_64+0x32/0x50
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fde28c3be57
Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51
c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
RSP: 002b:00007ffc09330028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde28c3be57
RDX: 0000000000000000 RSI: 00007ffc09330090 RDI: 0000000000000003
RBP: 000000005f45f911 R08: 0000000000000001 R09: 00007ffc0933012c
R10: 0000000000000076 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc09330290 R14: 00007ffc09330eee R15: 00005610e48ed020
Fixes: 1bff1a0c9bbd ("ipv4: Add function to send route updates")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/fib_trie.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -2121,7 +2121,8 @@ void fib_info_notify_update(struct net *
struct hlist_head *head = &net->ipv4.fib_table_hash[h];
struct fib_table *tb;
- hlist_for_each_entry_rcu(tb, head, tb_hlist)
+ hlist_for_each_entry_rcu(tb, head, tb_hlist,
+ lockdep_rtnl_is_held())
__fib_info_notify_update(net, tb, info);
}
}
next prev parent reply other threads:[~2020-09-11 14:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 12:47 [PATCH 5.8 00/16] 5.8.9-rc1 review Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 01/16] io_uring: fix cancel of deferred reqs with ->files Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 02/16] io_uring: fix linked deferred ->files cancellation Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 03/16] RDMA/cma: Simplify DEVICE_REMOVAL for internal_id Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 04/16] RDMA/cma: Using the standard locking pattern when delivering the removal event Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 05/16] RDMA/cma: Remove unneeded locking for req paths Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 06/16] RDMA/cma: Execute rdma_cm destruction from a handler properly Greg Kroah-Hartman
2020-09-11 12:47 ` Greg Kroah-Hartman [this message]
2020-09-11 12:47 ` [PATCH 5.8 08/16] ipv6: Fix sysctl max for fib_multipath_hash_policy Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 09/16] netlabel: fix problems with mapping removal Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 10/16] net: usb: dm9601: Add USB ID of Keenetic Plus DSL Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 11/16] sctp: not disable bh in the whole sctp_get_port_local() Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 12/16] taprio: Fix using wrong queues in gate mask Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 13/16] tipc: fix shutdown() of connectionless socket Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 14/16] tipc: fix using smp_processor_id() in preemptible Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 15/16] net: disable netpoll on fresh napis Greg Kroah-Hartman
2020-09-11 12:47 ` [PATCH 5.8 16/16] mptcp: free acked data before waiting for more memory Greg Kroah-Hartman
2020-09-11 17:10 ` [PATCH 5.8 00/16] 5.8.9-rc1 review Jon Hunter
2020-09-12 12:44 ` Greg Kroah-Hartman
2020-09-11 22:19 ` Shuah Khan
2020-09-12 12:44 ` Greg Kroah-Hartman
2020-09-12 2:19 ` Guenter Roeck
2020-09-12 12:44 ` Greg Kroah-Hartman
2020-09-12 7:27 ` Naresh Kamboju
2020-09-12 12:44 ` Greg Kroah-Hartman
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