Add a test that checks that if pid namespaces are configured the fdinfo
file of a pidfd contains an NSpid: entry containing the process id in
the current and additionally all nested namespaces. In the case that
a pidfd is from a pid namespace not in the same namespace hierarchy as
the process accessing the fdinfo file, ensure the 'NSpid' shows 0 for
that pidfd, analogous to the 'Pid' entry.
Signed-off-by: Christian Kellner <christian@kellner.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191014162034.2185-2-ckellner@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This adds testing for polling on pidfd of a process being killed. Test runs
10000 iterations by default to stress test pidfd polling functionality.
It accepts an optional command-line parameter to override the number or
iterations to run.
Specifically, it tests for:
- pidfd_open on a child process succeeds
- pidfd_send_signal on a child process succeeds
- polling on pidfd succeeds and returns exactly one event
- returned event is POLLIN
- event is received within 3 secs of the process being killed
10000 iterations was chosen because of the race condition being tested
which is not consistently reproducible but usually is revealed after less
than 2000 iterations.
Reveals race fixed by commit b191d6491b ("pidfd: fix a poll race when setting exit_state")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Link: https://lore.kernel.org/r/20190726162226.252750-2-surenb@google.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Add tests for pidfd_wait() and CLONE_WAIT_PID:
- test that waitid(P_PIDFD) fails on /proc/<pid>
- test that waitid(P_PIDFD) fails on /dev/null
- test that waitid(P_PIDFD) can wait on a pidfd
- test that waitid(P_PIDFD) can wait on a pidfd and return siginfo_t
- test that waitid(P_PIDFD) works with WEXITED
- test that waitid(P_PIDFD) works with WSTOPPED
- test that waitid(P_PIDFD) works with WUNTRACED
- test that waitid(P_PIDFD) works with WCONTINUED
- test that waitid(P_PIDFD) works with WNOWAIT
- test that waitid(P_PIDFD)works with WNOHANG
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20190727222229.6516-3-christian@brauner.io
This adds testing for the new pidfd_open() syscalls. Specifically, we test:
- that no invalid flags can be passed to pidfd_open()
- that no invalid pid can be passed to pidfd_open()
- that a pidfd can be retrieved with pidfd_open()
- that the retrieved pidfd references the correct pid
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Other than verifying pidfd based polling, the tests make sure that
wait semantics are preserved with the pidfd poll. Notably the 2 cases:
1. If a thread group leader exits while threads still there, then no
pidfd poll notifcation should happen.
2. If a non-thread group leader does an execve, then the thread group
leader is signaled to exit and is replaced with the execing thread
as the new leader, however the parent is not notified in this case.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
As suggested by Andrew Morton in [1] add selftests for the new
sys_pidfd_send_signal() syscall:
/* test_pidfd_send_signal_syscall_support */
Test whether the pidfd_send_signal() syscall is supported and the tests can
be run or need to be skipped.
/* test_pidfd_send_signal_simple_success */
Test whether sending a signal via a pidfd works.
/* test_pidfd_send_signal_exited_fail */
Verify that sending a signal to an already exited process fails with ESRCH.
/* test_pidfd_send_signal_recycled_pid_fail */
Verify that a recycled pid cannot be signaled via a pidfd referring to an
already exited process that had the same pid (cf. [2], [3]).
[1]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/
[2]: https://lore.kernel.org/lkml/20181230210245.GA30252@mail.hallyn.com/
[3]: https://lore.kernel.org/lkml/20181230232711.7aayb7vnhogbv4co@brauner.io/
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Tycho Andersen <tycho@tycho.ws>
Acked-by: Serge Hallyn <serge@hallyn.com>
Christian Kellner