[CRIU] test/others/rpc test cases

[Adrian Reber]

On Wed, May 16, 2018 at 05:16:12PM +0100, Dmitry Safonov wrote:
> 2018-05-16 16:52 GMT+01:00 Adrian Reber <adrian at lisas.de>:
> > we quickly chatted about the tests in test/others/rpc and I had a look
> > at it.
> >
> > One test (errno.py) dumps itself, keeps on running and tries to restore
> > itself. This should (and does fail) as the PID is already in use by the
> > test case. The test case wants to to test the error handling of 'criu
> > service'. But CRIU just kills all processes which it failed to restore
> > in criu/cr-restore.c (around line 2240 : kill(vpid(pi), SIGKILL);).
> >
> > As the test case is killed by CRIU it counts as a failure. I guess this
> > used to work at some point in time, but with 3.8.1 it does not.
> >
> > I am not sure what the right solution is. Should CRIU kill a process if
> > restore fails, probably to make sure that no half restored process still
> > exists. Maybe the test case does not make sense anymore...
> >
> > Do you have any thoughts on this? Is this a CRIU bug or a wrong test case?
> 
> It looks to me like a valid test. CRIU shouldn't kill existing tasks with
> reused PID. Do we run this errno.py on Travis?
> 
> I haven't even compile tested, but something like this might fix?
> 
> --->8---
> --- a/criu/cr-restore.c
> +++ b/criu/cr-restore.c
> @@ -1510,6 +1510,7 @@ static int do_fork_with_pid(struct pstree_item
> *item, struct ns_id *pid_ns, stru
>         if (pid < 0) {
>                 pr_perror("Can't clone()");
>                 ret = -1;
> +               hlp_pid->ns[i].virt = -1;
>                 goto unblock;
>         }
> 
> 
> -- 

No, the test case is still killed by CRIU. That is the end of the
restore log file (with additional printouts from my testing):

(00.005773) PID: real 25375 virt 25374
(00.005811) Error (criu/cr-restore.c:1869): Pid 25375 do not match expected 25374 (task 25374)
(00.005863) Error (criu/cr-restore.c:2392): Failed to wait inprogress tasks
(00.005869) Warn  (criu/cr-restore.c:2561): About to kill 25374
(00.007245) Error (criu/namespaces.c:1604): Spurious pid ns helper: pid=25375
(00.007256) Error (criu/cr-restore.c:1629): 25375 exited, status=1
(00.007266) Error (criu/cr-restore.c:2571): Restoring FAILED.


		Adrian