Bug 209427
| Summary: | Incorrect timestamp cause packet to be dropped | ||
|---|---|---|---|
| Product: | Networking | Reporter: | ep4eg (abt-admin) |
| Component: | Other | Assignee: | Stephen Hemminger (stephen) |
| Status: | NEW --- | ||
| Severity: | normal | ||
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 5.8.10 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
After upgrading from my 3.10 to 5.8.10 I found out some of my packets are getting dropped by ipvlan interface (I'm using qdisk fq). Debugging session led me to the place where this happens net/sched/sch_fq.c:464 ... if (fq_packet_beyond_horizon(skb, q)) { if (q->horizon_drop) { q->stat_horizon_drops++; return qdisc_drop(skb, sch, to_free); } q->stat_horizon_caps++; skb->tstamp = q->ktime_cache + q->horizon; } ... then I noticed that in some cases skb->tstamp is equal to real ts whereas in the regular cases where a packet pass through it's time since kernel boot. This doesn't make any sense for me as this condition is satisfied constantly net/sched/sch_fq.c:439 static bool fq_packet_beyond_horizon(const struct sk_buff *skb, const struct fq_sched_data *q) { return unlikely((s64)skb->tstamp > (s64)(q->ktime_cache + q->horizon)); } Any ideas on what it can be? some outputs: [Tue Sep 29 14:59:06 2020] DBG: TIME: trid: -1081131982. all: q->ktime_cache 328453964122, skb->tstamp 1601391546982793177 << [Tue Sep 29 14:59:06 2020] DBG: TIME: trid: -1485308564. all: q->ktime_cache 334998110463, skb->tstamp 335012588783 ... [Tue Sep 29 14:59:06 2020] DBG: TIME: trid: -1010372082. all: q->ktime_cache 335873778729, skb->tstamp 335741726080 [Tue Sep 29 14:59:06 2020] DBG: TIME: trid: 192888327. all: q->ktime_cache 335860696387, skb->tstamp 335870531339 [Tue Sep 29 14:59:07 2020] DBG: TIME: trid: -1463571809. all: q->ktime_cache 335305774517, skb->tstamp 1601391548109319017 << perf trace: curl 32613 [014] 1546.957467: skb:kfree_skb: skbaddr=0xffff888f57159ae0 protocol=2048 location=0xffffffff817bfdad 9bfd56 kfree_skb (/lib/modules/5.8.10/build/vmlinux) 9bfd56 kfree_skb (/lib/modules/5.8.10/build/vmlinux) 9bfdad kfree_skb_list (/lib/modules/5.8.10/build/vmlinux) 9da2b1 __dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 9da380 dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 1f39 vlan_dev_open ([8021q]) 9d9851 dev_hard_start_xmit (/lib/modules/5.8.10/build/vmlinux) 9d9d05 __dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 9da380 dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 9d9d05 __dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 9da380 dev_queue_xmit (/lib/modules/5.8.10/build/vmlinux) 9e32c3 neigh_connected_output (/lib/modules/5.8.10/build/vmlinux) a68cdb ip_finish_output2 (/lib/modules/5.8.10/build/vmlinux) a69b77 __ip_finish_output (/lib/modules/5.8.10/build/vmlinux) a69cad ip_finish_output (/lib/modules/5.8.10/build/vmlinux) a6b65a ip_output (/lib/modules/5.8.10/build/vmlinux) f2e4 ip_vs_tunnel_xmit ([ip_vs]) 536a ip_vs_nat_icmp ([ip_vs]) 5913 ip_vs_out_icmp ([ip_vs]) 59c6 ip_vs_out_icmp ([ip_vs]) a58255 nf_hook_slow (/lib/modules/5.8.10/build/vmlinux) a656f1 ip_local_deliver (/lib/modules/5.8.10/build/vmlinux) a64e07 ip_rcv_finish (/lib/modules/5.8.10/build/vmlinux) b717bb ip_sabotage_in (/lib/modules/5.8.10/build/vmlinux) a58255 nf_hook_slow (/lib/modules/5.8.10/build/vmlinux) a657a0 ip_rcv (/lib/modules/5.8.10/build/vmlinux) 9db608 __netif_receive_skb_one_core (/lib/modules/5.8.10/build/vmlinux) 9db658 __netif_receive_skb (/lib/modules/5.8.10/build/vmlinux) 9db6e9 netif_receive_skb (/lib/modules/5.8.10/build/vmlinux) b5c5b6 br_netif_receive_skb (/lib/modules/5.8.10/build/vmlinux) b5c7d3 br_pass_frame_up (/lib/modules/5.8.10/build/vmlinux) b5c94d br_handle_frame_finish (/lib/modules/5.8.10/build/vmlinux) b7253b br_nf_hook_thresh (/lib/modules/5.8.10/build/vmlinux) b72fb0 br_nf_pre_routing_finish (/lib/modules/5.8.10/build/vmlinux) b733bc br_nf_pre_routing (/lib/modules/5.8.10/build/vmlinux) b5cdf1 br_handle_frame (/lib/modules/5.8.10/build/vmlinux) 9da8c8 __netif_receive_skb_core (/lib/modules/5.8.10/build/vmlinux) 9db5bf __netif_receive_skb_one_core (/lib/modules/5.8.10/build/vmlinux) 9db658 __netif_receive_skb (/lib/modules/5.8.10/build/vmlinux) 9db8a9 process_backlog (/lib/modules/5.8.10/build/vmlinux) 9dd337 net_rx_action (/lib/modules/5.8.10/build/vmlinux) e000e1 __do_softirq (/lib/modules/5.8.10/build/vmlinux) c010c2 asm_call_on_stack (/lib/modules/5.8.10/build/vmlinux) 235bef do_softirq_own_stack (/lib/modules/5.8.10/build/vmlinux) 297f86 do_softirq.part.0 (/lib/modules/5.8.10/build/vmlinux) 297fe0 __local_bh_enable_ip (/lib/modules/5.8.10/build/vmlinux) a68cef ip_finish_output2 (/lib/modules/5.8.10/build/vmlinux) a69b77 __ip_finish_output (/lib/modules/5.8.10/build/vmlinux) a69cad ip_finish_output (/lib/modules/5.8.10/build/vmlinux) a6b65a ip_output (/lib/modules/5.8.10/build/vmlinux) a6ad4d ip_local_out (/lib/modules/5.8.10/build/vmlinux) a6b097 __ip_queue_xmit (/lib/modules/5.8.10/build/vmlinux) a8f740 ip_queue_xmit (/lib/modules/5.8.10/build/vmlinux) a89746 __tcp_transmit_skb (/lib/modules/5.8.10/build/vmlinux) a8a5de tcp_connect (/lib/modules/5.8.10/build/vmlinux) a90f73 tcp_v4_connect (/lib/modules/5.8.10/build/vmlinux) aad59a __inet_stream_connect (/lib/modules/5.8.10/build/vmlinux) aad88b inet_stream_connect (/lib/modules/5.8.10/build/vmlinux) 9b3e3f __sys_connect_file (/lib/modules/5.8.10/build/vmlinux) 9b3ef1 __sys_connect (/lib/modules/5.8.10/build/vmlinux) 9b3f3a __x64_sys_connect (/lib/modules/5.8.10/build/vmlinux) b896b2 do_syscall_64 (/lib/modules/5.8.10/build/vmlinux) c0008c entry_SYSCALL_64 (/lib/modules/5.8.10/build/vmlinux) 53878 [unknown] (/lib/ld-musl-x86_64.so.1) 0 [unknown] ([unknown]) 0 [unknown] ([unknown])