Subject: [TEST] amt.sh crashes smcrouted

From: Jakub Kicinski <[email-masked]>
Date: Thu, 2 May 2024 13:00:49 -0700

Hi Taehee Yoo!

We started running amt tests in the netdev CI, and it looks like it
hangs - or at least it doesn't produce any output for long enough
for the test runner to think it hung.

While looking at the logs, however, I see:

[    3.361660] smcrouted[294]: segfault at 7fff480c95f3 ip 00000000004034e4 sp 00007fff480b9410 error 6 in smcrouted[402000+a000] likely on CPU 3 (core 3, socket 0)
[    3.361812] Code: 74 24 38 89 ef e8 4c 33 00 00 44 0f b7 f8 66 39 84 24 e2 01 00 00 75 09 45 85 ed 0f 85 ed 01 00 00 48 8b 44 24 38 0f b6 40 33 <42> 88 84 3c e4 01 00 00 48 8b 3b 48 8d 54 24 38 48 8d 74 24 50 e8

https://netdev-3.bots.linux.dev/vmksft-net/results/577882/4-amt-sh/

So I think the cause may be a bug in smcroute.

We use smcroute build from latest git
# cd smcroute/
# git log -1 --oneline
cd25930 .github: use same CFLAGS for both configure runs
# smcroute -v
SMCRoute v2.5.6

Could you check if you can repro this crash?