From: Joel Fernandes <joel@joelfernandes.org>
To: Tycho Andersen <tycho@tycho.ws>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Christian Brauner <christian@brauner.io>,
dancol@google.com, "Eric W. Biederman" <ebiederm@xmission.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
jannh@google.com, Jann Horn <jann@thejh.net>,
Jonathan Kowalski <bl0pbl33p@gmail.com>,
kernel-team@android.com, linux-kselftest@vger.kernel.org,
luto@amacapital.net, Michal Hocko <mhocko@suse.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
rostedt@goodmis.org, Serge Hallyn <serge@hallyn.com>,
Shuah Khan <shuah@kernel.org>,
sspatil@google.com, Stephen Rothwell <sfr@canb.auug.org.au>,
surenb@google.com, Thomas Gleixner <tglx@linutronix.de>,
timmurray@google.com, torvalds@linux-foundation.org
Subject: Re: [PATCH v1 2/2] Add selftests for pidfd polling
Date: Fri, 26 Apr 2019 09:47:19 -0400 [thread overview]
Message-ID: <20190426134719.GB261279@google.com> (raw)
In-Reply-To: <20190425200035.GC30500@cisco>
On Thu, Apr 25, 2019 at 02:00:35PM -0600, Tycho Andersen wrote:
> On Thu, Apr 25, 2019 at 03:00:10PM -0400, Joel Fernandes (Google) wrote:
> >
> > +void *test_pidfd_poll_exec_thread(void *priv)
>
> I think everything in this file can be static, there's this one and
> 3-4 below.
>
> > +int test_pidfd_poll_exec(int use_waitpid)
> > +{
> > + int pid, pidfd = 0;
> > + int status, ret;
> > + pthread_t t1;
> > + time_t prog_start = time(NULL);
> > + const char *test_name = "pidfd_poll check for premature notification on child thread exec";
> > +
> > + ksft_print_msg("Parent: pid: %d\n", getpid());
> > + pid = pidfd_clone(CLONE_PIDFD, &pidfd, child_poll_exec_test);
>
> If pidfd_clone() fails here, I think things will go haywire below.
>
> > + ksft_print_msg("Parent: Waiting for Child (%d) to complete.\n", pid);
> > +
> > + if (use_waitpid) {
> > + ret = waitpid(pid, &status, 0);
> > + if (ret == -1)
> > + ksft_print_msg("Parent: error\n");
> > +
> > + if (ret == pid)
> > + ksft_print_msg("Parent: Child process waited for.\n");
> > + } else {
> > + poll_pidfd(test_name, pidfd);
> > + }
> > +
> > + time_t prog_time = time(NULL) - prog_start;
> > +
> > + ksft_print_msg("Time waited for child: %lu\n", prog_time);
> > +
> > + close(pidfd);
> > +
> > + if (prog_time < CHILD_THREAD_MIN_WAIT || prog_time > CHILD_THREAD_MIN_WAIT + 2)
> > + ksft_exit_fail_msg("%s test: Failed\n", test_name);
> > + else
> > + ksft_test_result_pass("%s test: Passed\n", test_name);
> > +}
> > +
> > +void *test_pidfd_poll_leader_exit_thread(void *priv)
> > +{
> > + char waittime[256];
> > +
> > + ksft_print_msg("Child Thread: starting. pid %d tid %d ; and sleeping\n",
> > + getpid(), syscall(SYS_gettid));
> > + sleep(CHILD_THREAD_MIN_WAIT);
> > + ksft_print_msg("Child Thread: DONE. pid %d tid %d\n", getpid(), syscall(SYS_gettid));
> > + return NULL;
> > +}
> > +
> > +static time_t *child_exit_secs;
> > +static int child_poll_leader_exit_test(void *args)
> > +{
> > + pthread_t t1, t2;
> > +
> > + ksft_print_msg("Child: starting. pid %d tid %d\n", getpid(), syscall(SYS_gettid));
> > + pthread_create(&t1, NULL, test_pidfd_poll_leader_exit_thread, NULL);
> > + pthread_create(&t2, NULL, test_pidfd_poll_leader_exit_thread, NULL);
> > +
> > + /*
> > + * glibc exit calls exit_group syscall, so explicity call exit only
> > + * so that only the group leader exits, leaving the threads alone.
> > + */
> > + *child_exit_secs = time(NULL);
> > + syscall(SYS_exit, 0);
> > +}
> > +
> > +int test_pidfd_poll_leader_exit(int use_waitpid)
> > +{
> > + int pid, pidfd = 0;
> > + int status, ret;
> > + time_t prog_start = time(NULL);
> > + const char *test_name = "pidfd_poll check for premature notification on non-empty"
> > + "group leader exit";
> > +
> > + child_exit_secs = mmap(NULL, sizeof *child_exit_secs, PROT_READ | PROT_WRITE,
> > + MAP_SHARED | MAP_ANONYMOUS, -1, 0);
> > +
> > + ksft_print_msg("Parent: pid: %d\n", getpid());
> > + pid = pidfd_clone(CLONE_PIDFD, &pidfd, child_poll_leader_exit_test);
>
> Same problem here, I think.
All comments address and fixed in the next revision, thanks!
- Joel
next prev parent reply other threads:[~2019-04-26 13:47 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-25 19:00 [PATCH v1 1/2] Add polling support to pidfd Joel Fernandes (Google)
2019-04-25 19:00 ` [PATCH v1 2/2] Add selftests for pidfd polling Joel Fernandes (Google)
2019-04-25 20:00 ` Tycho Andersen
2019-04-26 13:47 ` Joel Fernandes [this message]
2019-04-25 21:29 ` Christian Brauner
2019-04-25 22:07 ` Daniel Colascione
2019-04-26 17:26 ` Joel Fernandes
2019-04-26 19:35 ` Daniel Colascione
2019-04-26 20:31 ` Joel Fernandes
2019-04-26 13:42 ` Joel Fernandes
2019-04-25 22:24 ` [PATCH v1 1/2] Add polling support to pidfd Christian Brauner
2019-04-26 14:23 ` Joel Fernandes
2019-04-26 15:21 ` Christian Brauner
2019-04-26 15:31 ` Christian Brauner
2019-04-28 16:24 ` Oleg Nesterov
2019-04-29 14:02 ` Joel Fernandes
2019-04-29 14:07 ` Joel Fernandes
2019-04-29 14:25 ` Oleg Nesterov
2019-04-29 14:20 ` Oleg Nesterov
2019-04-29 16:32 ` Joel Fernandes
2019-04-30 11:53 ` Oleg Nesterov
2019-04-30 12:07 ` Oleg Nesterov
2019-04-30 15:49 ` Joel Fernandes
2019-04-26 14:58 ` Christian Brauner
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