Subject: Re: [PATCH net v2 0/2] selftests: mptcp: connect: cover alt modes

From: Jakub Kicinski <[email-masked]>
Date: Wed, 16 Jul 2025 07:26:02 -0700

On Tue, 15 Jul 2025 18:53:08 -0700 Jakub Kicinski wrote:
> On Tue, 15 Jul 2025 20:43:27 +0200 Matthieu Baerts (NGI0) wrote:
> > mptcp_connect.sh can be executed manually with "-m <MODE>" and "-C" to
> > make sure everything works as expected when using "mmap" and "sendfile"
> > modes instead of "poll", and with the MPTCP checksum support.
> > 
> > These modes should be validated, but they are not when the selftests are
> > executed via the kselftest helpers. It means that most CIs validating
> > these selftests, like NIPA for the net development trees and LKFT for
> > the stable ones, are not covering these modes.
> > 
> > To fix that, new test programs have been added, simply calling
> > mptcp_connect.sh with the right parameters.
> > 
> > The first patch can be backported up to v5.6, and the second one up to
> > v5.14.  
> 
> Looks like the failures that Paolo flagged yesterday:
> 
> https://lore.kernel.org/all/[email-masked]/
> 
> are back as soon as this hit NIPA :(
> 
> https://netdev.bots.linux.dev/contest.html?branch=net-next-2025-07-16--00-00&executor=vmksft-mptcp&pw-n=0&pass=0
> 
> No idea why TBH, the tests run sequentially and connect.sh run before
> any of the new ones.
> 
> I'm gonna leave it in patchwork in case the next run is clean,
> please use pw-bot to discard them if they keep failing.

It failed again on the latest run, in a somewhat more concerning way :(

# (duration 30279ms) [FAIL] file received by server does not match (in, out):
# -rw------- 1 root root 5171914 Jul 16 05:24 /tmp/tmp.W2c96hxSIz
# Trailing bytes are: 
# w,ѐ)-rw------- 1 root root 5166208 Jul 16 05:24 /tmp/tmp.s33PNcrN6M
# Trailing bytes are: 
# (<v /&^<ֱrnFsaC7INFO: with peek mode: saveAfterPeek

https://netdev-3.bots.linux.dev/vmksft-mptcp/results/211121/4-mptcp-connect-sh/stdout

BTW feeding the random data into hexdump-like formatter seems
advisable? :P