Re: stap server is not able to use

[Martin Cermak <mcermak@redhat.com>]

Hi Eric,

On  Sun  2023-12-03  13:03 , Lee Eric via Systemtap wrote:
> Hi,
> 
> I just noticed my stap scripts need to run via stap-server and I
> followed the doc link https://sourceware.org/systemtap/wiki/SecureBoot
> to set up stap server. However, I feel like the error messages from
> the stap command is really odd:
> 
> # stap --list-server=all
> ...
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.5.10-300.fc39.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.5.10-200.fc38.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.3.8-200.fc38.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.3.8-100.fc37.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.3.12-200.fc38.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
>  host=thinkpad01.local address=127.0.0.1 port=44621
> sysinfo="6.5.9-200.fc38.x86_64 x86_64" version=5.0
> certinfo="00:c1:73:c9:a1"
> ...
> 
> And I'm using Fedora 39, so I would like to test if stap can connect
> to a server regardless the stap command ONLY accepting
> hostname/ip/cert serial which they are all the same.
> 
> # stap -vvv --use-server=127.0.0.1:44621 -e 'probe begin { exit() }'
> ...
> Session arch: x86_64 release: 6.5.10-300.fc39.x86_64
> Build tree: "/lib/modules/6.5.10-300.fc39.x86_64/build"
> Using a compile server.
> Running sh -c cd '/tmp/stapvTSXTA/client' && zip -qr
> '/tmp/stapvTSXTA/client.zip' *
> Spawn waitpid result (0x0): 0
> Servers matching 127.0.0.1:44621:
>  host=unknown address=127.0.0.1 port=44621 sysinfo="unknown"
> version=unknown certinfo="unknown"
> All specified servers:
>  host=unknown address=127.0.0.1 port=44621 sysinfo="unknown"
> version=unknown certinfo="unknown"
> Unable to connect to a server.
> Passes: via server ? using 264956virt/19200res/16128shr/2424data kb,
> in 0usr/0sys/4real ms.
> Passes: via server failed.  Try again with another '-v' option.
> The kernel on your system requires modules to be signed for loading.
> The module created by compiling your script must be signed by a
> systemtap compile-server.  [man stap-server]
> ...
> 
> What's the meaning of that error exactly? Why stap cannot match one
> server in this case? I also did wireshark and I'm sure stap didn't
> talk to the tcp port 44621
> 
> Is there any clue about this usage? Any help would be appreciated.

I think you are missing a `stap --trust-servers ...` step.  We
have a simple testcase for stap server in Fedora CI:

https://src.fedoraproject.org/rpms/systemtap/blob/rawhide/f/tests/Sanity/stap-server-basic-sanity/runtest.sh

One of relatively fresh logs showing how it worked on Fedora 39
is here:

https://artifacts.dev.testing-farm.io/9d3c8552-145d-424f-a4fb-ddda1f5ef58e/work-ci1wn81l3u/plans/ci/execute/data/guest/default-0/tests/Sanity/stap-server-basic-sanity-32/output.txt

Hope this helps,
Martin