diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/tst-pidfd_getpid.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/tst-pidfd_getpid.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/tst-pidfd_getpid.c b/sysdeps/unix/sysv/linux/tst-pidfd_getpid.c new file mode 100644 index 0000000..e48eed7 --- /dev/null +++ b/sysdeps/unix/sysv/linux/tst-pidfd_getpid.c @@ -0,0 +1,123 @@ +/* Specific tests for Linux pidfd_getpid. + Copyright (C) 2023 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 <sched.h> +#include <stdlib.h> +#include <support/check.h> +#include <support/xunistd.h> +#include <support/test-driver.h> +#include <sys/pidfd.h> +#include <sys/wait.h> +#include <sys/mount.h> + +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"); + if (errno == EPERM) + FAIL_UNSUPPORTED ("kernel does not allow pidfd_getfd, skipping test"); + } + + /* Check if pidfd_getpid returns EREMOTE for process not in current + namespace. */ + { + pid_t child0 = xfork (); + TEST_VERIFY_EXIT (child0 >= 0); + if (child0 == 0) + { + /* Create another unrelated descriptor, so child2 will inherit the + file descriptor. */ + pid_t child1 = xfork (); + TEST_VERIFY_EXIT (child1 >= 0); + if (child1 == 0) + _exit (0); + int child1_pidfd = pidfd_open (child1, 0); + TEST_VERIFY_EXIT (child1_pidfd != -1); + + if (unshare (CLONE_NEWNS | CLONE_NEWUSER | CLONE_NEWPID) < 0) + { + /* Older kernels may not support all the options, or security + policy may block this call. */ + if (errno == EINVAL || errno == EPERM || errno == ENOSPC) + exit (EXIT_UNSUPPORTED); + FAIL_EXIT1 ("unshare user/fs/pid failed: %m"); + } + + if (mount (NULL, "/", NULL, MS_REC | MS_PRIVATE, 0) != 0) + { + /* This happens if we're trying to create a nested container, + like if the build is running under podman, and we lack + priviledges. */ + if (errno == EPERM) + _exit (EXIT_UNSUPPORTED); + else + _exit (EXIT_FAILURE); + } + + pid_t child2 = xfork (); + if (child2 > 0) + { + int status; + xwaitpid (child2, &status, 0); + TEST_VERIFY (WIFEXITED (status)); + xwaitpid (child1, &status, 0); + TEST_VERIFY (WIFEXITED (status)); + + _exit (WEXITSTATUS (status)); + } + + /* Now that we're pid 1 (effectively "root") we can mount /proc */ + if (mount ("proc", "/proc", "proc", 0, NULL) != 0) + { + if (errno == EPERM) + _exit (EXIT_UNSUPPORTED); + else + _exit (EXIT_FAILURE); + } + + TEST_COMPARE (pidfd_getpid (child1_pidfd), -1); + TEST_COMPARE (errno, EREMOTE); + + _exit (EXIT_SUCCESS); + } + int child0_pidfd = pidfd_open (child0, 0); + TEST_VERIFY_EXIT (child0_pidfd != -1); + + pid_t child0pid = pidfd_getpid (child0_pidfd); + + siginfo_t info; + TEST_COMPARE (waitid (P_PIDFD, child0_pidfd, &info, WEXITED), 0); + if (info.si_status == EXIT_UNSUPPORTED) + FAIL_UNSUPPORTED ("unable to unshare user/fs/pid"); + TEST_COMPARE (info.si_status, 0); + TEST_COMPARE (info.si_code, CLD_EXITED); + TEST_COMPARE (info.si_pid, child0pid); + } + + return 0; +} + +#include <support/test-driver.c> |