@@ -127,6 +127,7 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
tst-prctl \
tst-scm_rights \
tst-epoll \
+ tst-pidfd \
# tests
# Test for the symbol version of fcntl that was replaced in glibc 2.28.
new file mode 100644
@@ -0,0 +1,170 @@
+/* Basic tests for Linux pidfd interfaces.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+#include <support/process_state.h>
+#include <support/support.h>
+#include <support/xsignal.h>
+#include <support/xunistd.h>
+#include <support/xsocket.h>
+#include <sys/pidfd.h>
+#include <sys/wait.h>
+
+#define REMOTE_PATH "/dev/null"
+
+/* The pair of sockets used for coordination. The subprocess uses
+ sockets[1]. */
+static int sockets[2];
+
+static pid_t ppid;
+static uid_t puid;
+
+static void
+sighandler (int sig)
+{
+}
+
+static void
+subprocess (void)
+{
+ xsignal (SIGUSR1, sighandler);
+ xsignal (SIGUSR2, sighandler);
+
+ /* Check first pidfd_send_signal with default NULL siginfo_t argument. */
+ {
+ sigset_t set;
+ sigemptyset (&set);
+ sigaddset (&set, SIGUSR1);
+ siginfo_t info;
+ TEST_COMPARE (sigtimedwait (&set, &info, NULL), SIGUSR1);
+ TEST_COMPARE (info.si_signo, SIGUSR1);
+ TEST_COMPARE (info.si_errno, 0);
+ TEST_COMPARE (info.si_code, SI_USER);
+ TEST_COMPARE (info.si_pid, ppid);
+ TEST_COMPARE (info.si_uid, puid);
+ }
+
+ /* Check second pidfd_send_signal with crafted siginfo_t argument. */
+ {
+ sigset_t set;
+ sigemptyset (&set);
+ sigaddset (&set, SIGUSR2);
+ siginfo_t info;
+ TEST_COMPARE (sigtimedwait (&set, &info, NULL), SIGUSR2);
+ TEST_COMPARE (info.si_signo, SIGUSR2);
+ TEST_COMPARE (info.si_errno, EAGAIN);
+ TEST_COMPARE (info.si_code, -10);
+ TEST_COMPARE (info.si_pid, ppid);
+ TEST_COMPARE (info.si_uid, puid);
+ }
+
+ /* Send a local file descriptor value to check pidfd_getfd. */
+ int remote_fd = xopen (REMOTE_PATH, O_WRONLY | O_CLOEXEC, 0);
+ xsendto (sockets[1], &remote_fd, sizeof (remote_fd), 0, NULL, 0);
+
+ /* Wait for final pidfd_send_signal. */
+ pause ();
+
+ _exit (0);
+}
+
+static int
+do_test (void)
+{
+ {
+ /* The pidfd_getfd was the last one added on Linux. */
+ int r = pidfd_getfd (0, 0, 1);
+ TEST_VERIFY_EXIT (r == -1);
+ if (errno == ENOSYS)
+ FAIL_UNSUPPORTED ("kernel does not support pidfd_open, skipping test");
+ }
+
+ ppid = getpid ();
+ puid = getuid ();
+
+ TEST_COMPARE (socketpair (AF_UNIX, SOCK_STREAM, 0, sockets), 0);
+
+ pid_t pid = xfork ();
+ if (pid == 0)
+ {
+ xclose (sockets[0]);
+ subprocess ();
+ }
+ xclose (sockets[1]);
+
+ TEST_COMPARE (pidfd_open (-1, 0), -1);
+ TEST_COMPARE (errno, EINVAL);
+
+ int pidfd = pidfd_open (pid, 0);
+ TEST_VERIFY (pidfd != -1);
+
+ /* Wait for first sigtimedwait. */
+ support_process_state_wait (pid, support_process_state_sleeping);
+ TEST_COMPARE (pidfd_send_signal (pidfd, SIGUSR1, NULL, 0), 0);
+
+ /* Wait for second sigtimedwait. */
+ support_process_state_wait (pid, support_process_state_sleeping);
+ {
+ siginfo_t info =
+ {
+ .si_signo = SIGUSR2,
+ .si_errno = EAGAIN,
+ .si_code = -10,
+ .si_pid = ppid,
+ .si_uid = puid
+ };
+ TEST_COMPARE (pidfd_send_signal (pidfd, SIGUSR2, &info, 0), 0);
+ }
+
+ /* Get remote file descriptor to check for pidfd_getfd. */
+ {
+ int remote_fd;
+ xrecvfrom (sockets[0], &remote_fd, sizeof (remote_fd), 0, NULL, 0);
+
+ int fd = pidfd_getfd (pidfd, remote_fd, 0);
+ TEST_VERIFY (fd > 0);
+
+ char *path = xasprintf ("/proc/%d/fd/%d", pid, remote_fd);
+ char *resolved = xreadlink (path);
+ TEST_COMPARE_STRING (resolved, REMOTE_PATH);
+
+ int remote_fd_mode = fcntl (fd, F_GETFL);
+ TEST_VERIFY (remote_fd_mode != -1);
+ TEST_VERIFY (remote_fd_mode & O_WRONLY);
+
+ int remote_fd_flags = fcntl (fd, F_GETFD);
+ TEST_VERIFY (remote_fd_flags != -1);
+ TEST_VERIFY (remote_fd_flags & FD_CLOEXEC);
+ }
+
+ TEST_COMPARE (pidfd_send_signal (pidfd, SIGKILL, NULL, 0), 0);
+ {
+ siginfo_t info;
+ int r = waitid (P_PIDFD, pidfd, &info, WEXITED);
+ TEST_COMPARE (r, 0);
+ TEST_COMPARE (info.si_status, SIGKILL);
+ TEST_COMPARE (info.si_code, CLD_KILLED);
+ }
+
+ return 0;
+}
+
+#include <support/test-driver.c>