Re: [Qemu-devel] [PATCH v3 for-3.0] tests/libqtest: Improve kill_qemu()

[Eric Blake <eblake@redhat.com>]

On 08/03/2018 10:51 AM, Markus Armbruster wrote:
> Eric Blake <eblake@redhat.com> writes:
> 
>> In kill_qemu() we have an assert that checks that the QEMU process
>> didn't dump core:
>>              assert(!WCOREDUMP(wstatus));
>>
>> Unfortunately the WCOREDUMP macro here means the resulting message
>> is not very easy to comprehend on at least some systems:
>>
>> ahci-test: tests/libqtest.c:113: kill_qemu: Assertion `!(((__extension__ (((union { __typeof(wstatus) __in; int __i; }) { .__in = (wstatus) }).__i))) & 0x80)' failed.
>>
>> and it doesn't identify what signal the process took.
>>
>> -        if (pid == s->qemu_pid && WIFSIGNALED(wstatus)) {
>> -            assert(!WCOREDUMP(wstatus));
>> +        assert(pid == s->qemu_pid);
>> +        /*
>> +         * We expect qemu to exit with status 0; anything else is
>> +         * fishy and should be logged.  Abort except when death by
>> +         * signal is not accompanied by a coredump (as that's the only
>> +         * time it was likely that the user is trying to kill the
>> +         * testsuite early).
>> +         */
>> +        if (wstatus) {
>> +            die = true;
>> +            if (WIFEXITED(wstatus)) {
>> +                fprintf(stderr, "%s:%d: kill_qemu() tried to terminate QEMU "
>> +                        "process but encountered exit status %d\n",
>> +                        __FILE__, __LINE__, WEXITSTATUS(wstatus));
>> +            } else if (WIFSIGNALED(wstatus)) {
>> +                int sig = WTERMSIG(wstatus);

> 
> In review of v2, we found that WCOREDUMP() depends on the user's
> environment.  I doubt we should use it this way.
> 
> Why is suppressing the abort() when "the user is trying to kill the
> testsuite early" important?
> 

Only because the old code was special-casing based on whether WCOREDUMP. 
I'm not particularly attached to it, and am just fine submitting a v4 
that just quits on ALL death-by-signal, rather than caring whether a 
core dump was present.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org