[CRIU] [PATCH v2 3/5] tests: add a test for the case when there is a helper with a zombie child

[Tycho Andersen]

On Wed, Jun 29, 2016 at 01:57:06PM -0700, Andrew Vagin wrote:
> On Wed, Jun 29, 2016 at 03:53:23PM +0000, Tycho Andersen wrote:
> > v2: drop /bin/ps from test deps
> > 
> > Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
> > ---
> >  test/zdtm/.gitignore                      |   1 +
> >  test/zdtm/static/Makefile                 |   1 +
> >  test/zdtm/static/helper_zombie_child.c    | 104 ++++++++++++++++++++++++++++++
> >  test/zdtm/static/helper_zombie_child.desc |   1 +
> >  4 files changed, 107 insertions(+)
> >  create mode 100644 test/zdtm/static/helper_zombie_child.c
> >  create mode 100644 test/zdtm/static/helper_zombie_child.desc
> > 
> > diff --git a/test/zdtm/.gitignore b/test/zdtm/.gitignore
> > index 85e39a2..ec3c9d4 100644
> > --- a/test/zdtm/.gitignore
> > +++ b/test/zdtm/.gitignore
> > @@ -55,6 +55,7 @@
> >  /static/grow_map
> >  /static/grow_map02
> >  /static/grow_map03
> > +/static/helper_zombie_child
> >  /static/inotify00
> >  /static/inotify01
> >  /static/inotify02
> > diff --git a/test/zdtm/static/Makefile b/test/zdtm/static/Makefile
> > index 407a80f..1f465f0 100644
> > --- a/test/zdtm/static/Makefile
> > +++ b/test/zdtm/static/Makefile
> > @@ -150,6 +150,7 @@ TST_NOFILE	=				\
> >  		oom_score_adj			\
> >  		loginuid			\
> >  		cgroupns			\
> > +		helper_zombie_child		\
> >  #		jobctl00			\
> >  
> >  TST_FILE	=				\
> > diff --git a/test/zdtm/static/helper_zombie_child.c b/test/zdtm/static/helper_zombie_child.c
> > new file mode 100644
> > index 0000000..5c3ffa9
> > --- /dev/null
> > +++ b/test/zdtm/static/helper_zombie_child.c
> > @@ -0,0 +1,104 @@
> > +#define _GNU_SOURCE
> > +#include <unistd.h>
> > +#include <stdlib.h>
> > +#include <stdbool.h>
> > +#include <signal.h>
> > +#include <stddef.h>
> > +#include <sys/types.h>
> > +#include <sys/socket.h>
> > +#include <sys/wait.h>
> > +#include <sys/prctl.h>
> > +
> > +#include "zdtmtst.h"
> > +
> > +const char *test_doc	= "Check that a zombie with a helper parent is restored";
> > +const char *test_author	= "Tycho Andersen <tycho.andersen at canonical.com>";
> > +
> > +void setsid_and_fork(int sk)
> > +{
> > +	pid_t zombie;
> > +
> > +	setsid();
> > +
> > +	zombie = fork();
> > +	if (zombie < 0) {
> > +		fail("fork");
> > +		exit(1);
> > +	}
> > +
> > +	if (zombie == 0)
> > +		exit(0);
> > +
> > +	if (write(sk, &zombie, sizeof(zombie)) != sizeof(zombie)) {
> > +		fail("write");
> > +		exit(1);
> > +	}
> > +
> > +	close(sk);
> > +
> > +	exit(0);
> > +}
> > +
> > +int main(int argc, char **argv)
> > +{
> > +	pid_t pid, zombie;
> > +	int status, sk_pair[2];
> > +
> > +	if (setenv("ZDTM_NOREAP", "1", 1) < 0) {
> > +		fail("setenv");
> > +		return 1;
> > +	}
> > +
> > +	test_init(argc, argv);
> > +
> > +	if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sk_pair)) {
> > +		pr_perror("socketpair");
> > +		return 1;
> > +	}
> > +
> > +	pid = fork();
> > +	if (pid < 0) {
> > +		fail("fork");
> > +		return 1;
> > +	}
> > +
> > +	if (pid == 0) {
> > +		close(sk_pair[0]);
> > +		setsid_and_fork(sk_pair[1]);
> > +	}
> > +
> > +	close(sk_pair[1]);
> > +
> > +	if (read(sk_pair[0], &zombie, sizeof(zombie)) != sizeof(zombie)) {
> > +		fail("read");
> > +		kill(pid, SIGKILL);
> > +		return 1;
> > +	}
> > +
> > +	if (waitpid(pid, &status, 0) < 0) {
> > +		fail("waitpid");
> > +		return 1;
> > +	}
> > +
> > +	if (!WIFEXITED(status) || WEXITSTATUS(status)) {
> > +		fail("setsid_and_fork");
> > +		return 1;
> > +	}
> > +
> > +	if (kill(zombie, 0) < 0) {
> > +		fail("zombie already dead?");
> > +		return 1;
> > +	}
> 
> You need to wait when the signal will be delivered.

Hmm, yep. Actually we can't wait() here because it's not a child, but
we should wait for it above, nice catch. I'll resend, thanks!

> 
> > +
> > +	test_daemon();
> > +	test_waitsig();
> > +
> > +	/* XXX: we don't restore zombies with the right uid right now; they're all root */
> > +	if (kill(zombie, 0) < 0 && errno != EPERM) {
> > +		fail("zombie didn't survive restore");
> > +		return 1;
> > +	}
> > +
> > +	pass();
> > +	return 0;
> > +}
> > diff --git a/test/zdtm/static/helper_zombie_child.desc b/test/zdtm/static/helper_zombie_child.desc
> > new file mode 100644
> > index 0000000..6c4afe5
> > --- /dev/null
> > +++ b/test/zdtm/static/helper_zombie_child.desc
> > @@ -0,0 +1 @@
> > +{'flavor': 'ns uns'}
> > -- 
> > 2.7.4
> > 
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