On Mon, Feb 11, 2019 at 10:55:38AM +0200, Vlad Buslov wrote:
> Extend tcf_chain with new filter_chain_lock mutex. Always lock the chain
> when accessing filter_chain list, instead of relying on rtnl lock.
> Dereference filter_chain with tcf_chain_dereference() lockdep macro to
> verify that all users of chain_list have the lock taken.
>
> Rearrange tp insert/remove code in tc_new_tfilter/tc_del_tfilter to execute
> all necessary code while holding chain lock in order to prevent
> invalidation of chain_info structure by potential concurrent change. This
> also serializes calls to tcf_chain0_head_change(), which allows head change
> callbacks to rely on filter_chain_lock for synchronization instead of rtnl
> mutex.
>
> Signed-off-by: Vlad Buslov <vla...@mellanox.com>
> Acked-by: Jiri Pirko <j...@mellanox.com>
With this sequence [1] I get the following trace [2]. Bisected it to
this patch. Note that second filter is rejected by the device driver
(that's the intention). I guess it is not properly removed from the
filter chain in the error path?
Thanks
[1]
# tc qdisc add dev swp3 clsact
# tc filter add dev swp3 ingress pref 1 matchall skip_sw \
action mirred egress mirror dev swp7
# tc filter add dev swp3 ingress pref 2 matchall skip_sw \
action mirred egress mirror dev swp7
RTNETLINK answers: File exists
We have an error talking to the kernel, -1
# tc qdisc del dev swp3 clsact
[2]
[ 70.545131] kasan: GPF could be caused by NULL-ptr deref or user memory
access
[ 70.553394] general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
[ 70.560618] CPU: 2 PID: 2268 Comm: tc Not tainted
5.0.0-rc5-custom-02103-g415d39427317 #1304
[ 70.570065] Hardware name: Mellanox Technologies Ltd.
MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[ 70.580204] RIP: 0010:mall_reoffload+0x14a/0x760
[ 70.585382] Code: c1 0f 85 ba 05 00 00 31 c0 4d 8d 6c 24 34 b9 06 00 00 00
4c 89 ff f3 48 ab 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 14
02 4c 89 e8 83
e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 bd
[ 70.606382] RSP: 0018:ffff888231faefc0 EFLAGS: 00010207
[ 70.612235] RAX: dffffc0000000000 RBX: 1ffff110463f5dfe RCX: 0000000000000000
[ 70.620220] RDX: 0000000000000006 RSI: 1ffff110463f5e01 RDI: ffff888231faf040
[ 70.628206] RBP: ffff8881ef151a00 R08: 0000000000000000 R09: ffffed10463f5dfa
[ 70.636192] R10: ffffed10463f5dfa R11: 0000000000000003 R12: 0000000000000000
[ 70.644177] R13: 0000000000000034 R14: 0000000000000000 R15: ffff888231faf010
[ 70.652163] FS: 00007f46b5bf0800(0000) GS:ffff888236c00000(0000)
knlGS:0000000000000000
[ 70.661218] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 70.667649] CR2: 0000000001d590a8 CR3: 0000000231c3c000 CR4: 00000000001006e0
[ 70.675633] Call Trace:
[ 70.693046] tcf_block_playback_offloads+0x94/0x230
[ 70.710617] __tcf_block_cb_unregister+0xf7/0x2d0
[ 70.734143] mlxsw_sp_setup_tc+0x20f/0x660
[ 70.738739] tcf_block_offload_unbind+0x22b/0x350
[ 70.748898] __tcf_block_put+0x203/0x630
[ 70.769700] tcf_block_put_ext+0x2f/0x40
[ 70.774098] clsact_destroy+0x7a/0xb0
[ 70.782604] qdisc_destroy+0x11a/0x5c0
[ 70.786810] qdisc_put+0x5a/0x70
[ 70.790435] notify_and_destroy+0x8e/0xa0
[ 70.794933] qdisc_graft+0xbb7/0xef0
[ 70.809009] tc_get_qdisc+0x518/0xa30
[ 70.821530] rtnetlink_rcv_msg+0x397/0xa20
[ 70.835510] netlink_rcv_skb+0x132/0x380
[ 70.848419] netlink_unicast+0x4c0/0x690
[ 70.866019] netlink_sendmsg+0x929/0xe10
[ 70.882134] sock_sendmsg+0xc8/0x110
[ 70.886144] ___sys_sendmsg+0x77a/0x8f0
[ 70.924064] __sys_sendmsg+0xf7/0x250
[ 70.955727] do_syscall_64+0x14d/0x610
