Re: [Qemu-devel] [PATCH v3 2/1] libqtest: add more exit status checks

[Thomas Huth]

On 24.05.2018 18:11, Michael S. Tsirkin wrote:
> Add more checks on how did QEMU exit.
> 
> Legal ways to exit right now:
> - exit(0) or return from main
> - kill(SIGTERM) - sent by testing infrastructure
> 
> Anything else is illegal.
[...]
> -        if (pid == s->qemu_pid && WIFSIGNALED(wstatus)) {
> +        /* waitpid returns child PID on success */
> +        assert(pid == s->qemu_pid);
> +
> +        /* If exited on signal - check the reason: core dump is never OK */
> +        if (WIFSIGNALED(wstatus)) {
>              assert(!WCOREDUMP(wstatus));
>          }
> +        /* If exited normally - check exit status */
> +        if (WIFEXITED(wstatus)) {
> +            assert(!WEXITSTATUS(wstatus));
> +        }
> +        /* Valid ways to exit: right now only return from main or exit */
> +        assert(WIFEXITED(wstatus));
>      }
>  }

It's strange that you always get WIFEXITED(wstatus) == true here, even
if QEMU has been terminated by SIGTERM? I assume that's due to the fact
that QEMU intercepts SIGTERM and terminates via exit() instead? So I
think you could simply replace the last three asserts with:

        assert(WIFEXITED(wstatus) && !WEXITSTATUS(wstatus));

 Thomas