From d2a1ec20976e0c03c50e35b58c8a0b5093e3643b Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 28 Jan 2022 17:46:21 -0300 Subject: linux: Add tst-pidfd.c To check for the pidfd functions pidfd_open, pidfd_getfd, pid_send_signal, and waitid with P_PIDFD. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- sysdeps/unix/sysv/linux/tst-pidfd.c | 172 ++++++++++++++++++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd.c (limited to 'sysdeps/unix/sysv/linux/tst-pidfd.c') diff --git a/sysdeps/unix/sysv/linux/tst-pidfd.c b/sysdeps/unix/sysv/linux/tst-pidfd.c new file mode 100644 index 0000000000..d93b6faa6f --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-pidfd.c @@ -0,0 +1,172 @@ +/* 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 + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 syscall was the last in the set of pidfd related + syscalls added to the kernel. Use pidfd_getfd to decide if this + kernel has pidfd support that we can test. */ + int r = pidfd_getfd (0, 0, 1); + TEST_VERIFY_EXIT (r == -1); + if (errno == ENOSYS) + FAIL_UNSUPPORTED ("kernel does not support pidfd_getfd, 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 -- cgit 1.4.1