Re: [Qemu-devel] [PATCH] libqtest: fail if child coredumps

[Thomas Huth <thuth@redhat.com>]

On 24.05.2018 16:30, Michael S. Tsirkin wrote:
> Right now tests report OK status if QEMU crashes during cleanup.
> Let's catch that case and fail the test.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  tests/libqtest.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/libqtest.c b/tests/libqtest.c
> index 43fb97e..f869854 100644
> --- a/tests/libqtest.c
> +++ b/tests/libqtest.c
> @@ -103,8 +103,15 @@ static int socket_accept(int sock)
>  static void kill_qemu(QTestState *s)
>  {
>      if (s->qemu_pid != -1) {
> +        int wstatus = 0;
> +        pid_t pid;
> +
>          kill(s->qemu_pid, SIGTERM);
> -        waitpid(s->qemu_pid, NULL, 0);
> +        pid = waitpid(s->qemu_pid, &wstatus, 0);
> +
> +        if (pid == s->qemu_pid && WIFSIGNALED(wstatus)) {
> +            assert(!WCOREDUMP(wstatus));
> +        }
>      }
>  }

That's basically a good idea ... but I've already seen yet another issue
in the past already: QEMU sometimes simply hangs in an endless loop
during clean up and never terminates. I think we should detect that
situation, too.

So instead of killing QEMU at the end of the testing, I think we should
rather try to terminate it with the QMP "quit" command. If QEMU does not
terminate with an exit code of 0, then the test should be flagged a
failed (and only if QEMU did not terminate at all, it should be killed
with SIGKILL).

 Thomas