Investigate new v12.19.0 segfaults in tests.

[hertzg]

Describe the bug
Single test seems to be consistently failing
PR / test-integration (ubuntu-latest, 12) (pull_request) Failing after 59s — test-integration

The error seems to be tcpdump utility segfaulting but I'm not sure if it really is the problem as it only affects ubuntu-latest with node-12 so it might be node crashing due to various reasons.

[hertzg]

I'm more leaning towards segfault in node other than tcpdump as there seems to be keepalive packets being reported in the output.

Also the last passed PR workflow had Node 12.18.4/x64 and first failing one had 12.19.0/x64. This could be the reasons for segfault as well. Manual check would help.

References

• Last Passing Action
• First Failing Action

[hertzg]

Seems to be segfaulting only on v12.19.0 which is currently the latest LTS release needs a bit more investigation on what changed in node to cause this or might be related to node-ffi.

Node version	Release Date	Workflow Run
v10.22.1	2020-09-15	✔️ Passed
v12.18.4	2020-09-15	✔️ Passed
v14.11.0	2020-09-15	✔️ Passed
v14.12.0	2020-09-22	✔️ Passed
v14.13.0	2020-09-29	✔️ Passed
v12.19.0	2020-10-06	🛑 Failed
v14.13.1	2020-10-07	✔️ Passed
v14.14.0	2020-10-15	✔️ Passed

[hertzg]

Seems like there will be a revert of a change that caused issues with ABI. Need to re-test after the change is reverted on node.

[hertzg]

Waiting for nodejs/node#35777 to "bake" and get released.

[hertzg]

Revert seems to be included for 2020-11-24 Version 12.20.0 `Erbium' (LTS) release (proposal).

[MylesBorins]

@hertzg can you confirm that the segfault is fixed with the rc?

https://nodejs.org/download/rc/v12.20.0-rc.1/

[hertzg]

@MylesBorins ✔️ No segfaults with v12.20.0-rc.1, so far the tests finish normally. 🎉

hertz@hertz-ThinkPad-P51:~/projects/node-net-keepalive$ node --version
v12.20.0-rc.1
hertz@hertz-ThinkPad-P51:~/projects/node-net-keepalive$ npm --version
6.14.8
hertz@hertz-ThinkPad-P51:~/projects/node-net-keepalive$ npm run test:integration

> net-keepalive@1.3.9 test:integration /home/hertz/projects/node-net-keepalive
> mocha --recursive test/integration



  tcp-dump
waiting 10.5s for: $ tcpdump -pl -c 10 -i lo (port 34357 or port 49534) and ( tcp[tcpflags] & tcp-ack != 0 and ( (ip[2:2] - ((ip[0]&0xf)<<2) ) - ((tcp[12]&0xf0)>>2) ) == 0 ) 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on lo, link-type EN10MB (Ethernet), capture size 262144 bytes
20:29:40.382237 IP localhost.49534 > localhost.34357: Flags [.], ack 1301656948, win 64, options [nop,nop,TS val 953132890 ecr 953131880], length 0
20:29:40.382262 IP localhost.34357 > localhost.49534: Flags [.], ack 1, win 64, options [nop,nop,TS val 953132890 ecr 953131880], length 0
20:29:42.398217 IP localhost.49534 > localhost.34357: Flags [.], ack 1, win 64, options [nop,nop,TS val 953134906 ecr 953132890], length 0
20:29:42.398234 IP localhost.34357 > localhost.49534: Flags [.], ack 1, win 64, options [nop,nop,TS val 953134906 ecr 953131880], length 0
20:29:44.414230 IP localhost.49534 > localhost.34357: Flags [.], ack 1, win 64, options [nop,nop,TS val 953136922 ecr 953134906], length 0
20:29:44.414249 IP localhost.34357 > localhost.49534: Flags [.], ack 1, win 64, options [nop,nop,TS val 953136922 ecr 953131880], length 0
20:29:46.430224 IP localhost.49534 > localhost.34357: Flags [.], ack 1, win 64, options [nop,nop,TS val 953138938 ecr 953136922], length 0
20:29:46.430242 IP localhost.34357 > localhost.49534: Flags [.], ack 1, win 64, options [nop,nop,TS val 953138938 ecr 953131880], length 0
20:29:48.446238 IP localhost.49534 > localhost.34357: Flags [.], ack 1, win 64, options [nop,nop,TS val 953140954 ecr 953138938], length 0
20:29:48.446256 IP localhost.34357 > localhost.49534: Flags [.], ack 1, win 64, options [nop,nop,TS val 953140954 ecr 953131880], length 0
10 packets captured
20 packets received by filter
0 packets dropped by kernel
    ✓ should send keepalive packets on the wire (9126ms)


  1 passing (9s)