Re: [PATCH mptcp-net] selftests: mptcp: don't exit when a symbol not found

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 22/02/2024 8:56 am, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> mptcp_lib_kallsyms_has() will always exit when a symbol has not found, it
> breaks the test itself. Unexpected errors occur:
> 
>  007 userspace pm add & remove address
>        syn                                 [ OK ]
>        synack                              [ OK ]
>        ack                                 [ OK ]
>        add                                 [ OK ]
>        echo                                [ OK ]
>        mptcp_info subflows=2:2             [ OK ]
>        mptcp_info subflows_total=3:3       [ OK ]
>        mptcp_info add_addr_signal=2:2      [ OK ]
>        mptcp_info last_data_sent=191:18    [ OK ]
>        mptcp_info last_data_recv=40:68     [ OK ]
>        mptcp_info last_ack_recv=93:74      [ OK ]
>        dump addrs signal                   ERROR: missing feature: \
> 			mptcp_userspace_pm_dump_addr$ symbol not found
>  Cannot open network namespace "ns1-65d6fb5a-5FviVK": \
> 			No such file or directory
>  Cannot open network namespace "ns2-65d6fb5a-5FviVK": \
> 			No such file or directory
>  cmp: /tmp/tmp.a7osJs7Nj0: No such file or directory
>  cmp: /tmp/tmp.f02z6brCQu: No such file or directory
>  cat: /tmp/tmp.27TzxD2efV: No such file or directory
> not ok 1 test: selftest_mptcp_join # FAIL
> 
> To fix this, this patch adds a new argument 'continue' for the helper
> mptcp_lib_fail_if_expected_feature() to control whether exit or not.
> 
> Always set this argument to 1 in mptcp_lib_kallsyms_has().
> 
> Fixes: 83013bdf90a ("selftests: mptcp: connect: skip if MPTCP is not supported")

I'm not sure to understand why you sent this :)

The fixes commit ('d' is missing at the beginning) here mentions:

> Note that this check can also
> mark the test as failed if 'SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES' env
> var is set to 1: by doing that, we can make sure a test is not being
> skipped by mistake.

So the goal is to fail when the env var is set. Otherwise, we would miss
tests that are skipped by accident.

If you use 'mptcp-upstream-virtme-docker' and you want to run recent
selftests on an older kernel, you can add this to the docker command not
to exit if a feature is missing:

  -e INPUT_SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES=0

But clearly here, we don't want to continue if we expect all features to
work!

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.