Re: selftests/ftrace kprobe_eventname test fails on s390x QEMU (KVM/Linux)

[Sven Schnelle <svens@linux.ibm.com>]

Yunseong Kim <yskelg@gmail.com> writes:

> In my s390x archtecture, kprobe_eventname selftest have always failed
> because of rcu_sched stalls.
>
> My environment is QEMU Ubuntu 24.04 KVM Machine Linux version
> 6.8.0-36-generic (buildd@bos01-s390x-012) (s390x-linux-gnu-gcc-13
> (Ubuntu 13.2.0-23ubuntu4) 13.2.0, GNU ld (GNU Binutils for Ubuntu) 2.42) #36
>
> 1 configured CPUs, Linux is running under KVM in 64-bit mode
>
>
>  qemu-system-s390x -no-reboot -name auto-inst-test -nographic -m 4096 \
>    -drive file=disk-image.qcow2,format=qcow2,cache=none,if=virtio \
>    -netdev user,id=enc0,hostfwd=tcp::10000-:22 \
>    -device virtio-net-ccw,netdev=enc0 \
>    -qmp tcp:localhost:4444,server,nowait
>
>
> Currently, This failure can be always reproduced by this kselftests script:
>
>  # tools/testing/selftests/ftrace/ftracetest
> tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc
>
> I've investigating cause of line, then I find this line.
>
>  for i in `seq 0 255`; do
>    echo p $FUNCTION_FORK+${i} >> kprobe_events || continue
>  done

I think this is fixed with:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.10-rc5&id=c239c83ed5c558be3b5926c7f11639f02c8acd00

Regards,
Sven