diff options
| author | Vlad Buslov <vladbu@mellanox.com> | 2019-08-03 16:36:19 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-08-07 00:15:39 +0300 |
| commit | 67cbf7dedd03a63ca2fbd9df2049eabba7a37edf (patch) | |
| tree | a070b8dedee983ee82415fe636b0ca7d435c4d77 | |
| parent | c4bd48699beb92d6bb99d6139d1e9737cca73480 (diff) | |
| download | linux-67cbf7dedd03a63ca2fbd9df2049eabba7a37edf.tar.xz | |
net: sched: sample: allow accessing psample_group with rtnl
Recently implemented support for sample action in flow_offload infra leads
to following rcu usage warning:
[ 1938.234856] =============================
[ 1938.234858] WARNING: suspicious RCU usage
[ 1938.234863] 5.3.0-rc1+ #574 Not tainted
[ 1938.234866] -----------------------------
[ 1938.234869] include/net/tc_act/tc_sample.h:47 suspicious rcu_dereference_check() usage!
[ 1938.234872]
other info that might help us debug this:
[ 1938.234875]
rcu_scheduler_active = 2, debug_locks = 1
[ 1938.234879] 1 lock held by tc/19540:
[ 1938.234881] #0: 00000000b03cb918 (rtnl_mutex){+.+.}, at: tc_new_tfilter+0x47c/0x970
[ 1938.234900]
stack backtrace:
[ 1938.234905] CPU: 2 PID: 19540 Comm: tc Not tainted 5.3.0-rc1+ #574
[ 1938.234908] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[ 1938.234911] Call Trace:
[ 1938.234922] dump_stack+0x85/0xc0
[ 1938.234930] tc_setup_flow_action+0xed5/0x2040
[ 1938.234944] fl_hw_replace_filter+0x11f/0x2e0 [cls_flower]
[ 1938.234965] fl_change+0xd24/0x1b30 [cls_flower]
[ 1938.234990] tc_new_tfilter+0x3e0/0x970
[ 1938.235021] ? tc_del_tfilter+0x720/0x720
[ 1938.235028] rtnetlink_rcv_msg+0x389/0x4b0
[ 1938.235038] ? netlink_deliver_tap+0x95/0x400
[ 1938.235044] ? rtnl_dellink+0x2d0/0x2d0
[ 1938.235053] netlink_rcv_skb+0x49/0x110
[ 1938.235063] netlink_unicast+0x171/0x200
[ 1938.235073] netlink_sendmsg+0x224/0x3f0
[ 1938.235091] sock_sendmsg+0x5e/0x60
[ 1938.235097] ___sys_sendmsg+0x2ae/0x330
[ 1938.235111] ? __handle_mm_fault+0x12cd/0x19e0
[ 1938.235125] ? __handle_mm_fault+0x12cd/0x19e0
[ 1938.235138] ? find_held_lock+0x2b/0x80
[ 1938.235147] ? do_user_addr_fault+0x22d/0x490
[ 1938.235160] __sys_sendmsg+0x59/0xa0
[ 1938.235178] do_syscall_64+0x5c/0xb0
[ 1938.235187] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1938.235192] RIP: 0033:0x7ff9a4d597b8
[ 1938.235197] Code: 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 8f 0c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83
ec 28 89 54
[ 1938.235200] RSP: 002b:00007ffcfe381c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1938.235205] RAX: ffffffffffffffda RBX: 000000005d4497f9 RCX: 00007ff9a4d597b8
[ 1938.235208] RDX: 0000000000000000 RSI: 00007ffcfe381cb0 RDI: 0000000000000003
[ 1938.235211] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000006
[ 1938.235214] R10: 0000000000404ec2 R11: 0000000000000246 R12: 0000000000000001
[ 1938.235217] R13: 0000000000480640 R14: 0000000000000012 R15: 0000000000000001
Change tcf_sample_psample_group() helper to allow using it from both rtnl
and rcu protected contexts.
Fixes: a7a7be6087b0 ("net/sched: add sample action to the hardware intermediate representation")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/tc_act/tc_sample.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/tc_act/tc_sample.h b/include/net/tc_act/tc_sample.h index 0a559d4b6f0f..b4fce0fae645 100644 --- a/include/net/tc_act/tc_sample.h +++ b/include/net/tc_act/tc_sample.h @@ -44,7 +44,7 @@ static inline int tcf_sample_trunc_size(const struct tc_action *a) static inline struct psample_group * tcf_sample_psample_group(const struct tc_action *a) { - return rcu_dereference(to_sample(a)->psample_group); + return rcu_dereference_rtnl(to_sample(a)->psample_group); } #endif /* __NET_TC_SAMPLE_H */ |