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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/pidfd/pidfd_test.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/pidfd/pidfd_test.c')
-rw-r--r-- | tools/testing/selftests/pidfd/pidfd_test.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c new file mode 100644 index 000000000..79f543ad3 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -0,0 +1,573 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <linux/types.h> +#include <pthread.h> +#include <sched.h> +#include <signal.h> +#include <stdio.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <syscall.h> +#include <sys/epoll.h> +#include <sys/mman.h> +#include <sys/mount.h> +#include <sys/wait.h> +#include <time.h> +#include <unistd.h> + +#include "pidfd.h" +#include "../kselftest.h" + +#define str(s) _str(s) +#define _str(s) #s +#define CHILD_THREAD_MIN_WAIT 3 /* seconds */ + +#define MAX_EVENTS 5 + +static bool have_pidfd_send_signal; + +static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) +{ + size_t stack_size = 1024; + char *stack[1024] = { 0 }; + +#ifdef __ia64__ + return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd); +#else + return clone(fn, stack + stack_size, flags | SIGCHLD, NULL, pidfd); +#endif +} + +static int signal_received; + +static void set_signal_received_on_sigusr1(int sig) +{ + if (sig == SIGUSR1) + signal_received = 1; +} + +/* + * Straightforward test to see whether pidfd_send_signal() works is to send + * a signal to ourself. + */ +static int test_pidfd_send_signal_simple_success(void) +{ + int pidfd, ret; + const char *test_name = "pidfd_send_signal send SIGUSR1"; + + if (!have_pidfd_send_signal) { + ksft_test_result_skip( + "%s test: pidfd_send_signal() syscall not supported\n", + test_name); + return 0; + } + + pidfd = open("/proc/self", O_DIRECTORY | O_CLOEXEC); + if (pidfd < 0) + ksft_exit_fail_msg( + "%s test: Failed to open process file descriptor\n", + test_name); + + signal(SIGUSR1, set_signal_received_on_sigusr1); + + ret = sys_pidfd_send_signal(pidfd, SIGUSR1, NULL, 0); + close(pidfd); + if (ret < 0) + ksft_exit_fail_msg("%s test: Failed to send signal\n", + test_name); + + if (signal_received != 1) + ksft_exit_fail_msg("%s test: Failed to receive signal\n", + test_name); + + signal_received = 0; + ksft_test_result_pass("%s test: Sent signal\n", test_name); + return 0; +} + +static int test_pidfd_send_signal_exited_fail(void) +{ + int pidfd, ret, saved_errno; + char buf[256]; + pid_t pid; + const char *test_name = "pidfd_send_signal signal exited process"; + + if (!have_pidfd_send_signal) { + ksft_test_result_skip( + "%s test: pidfd_send_signal() syscall not supported\n", + test_name); + return 0; + } + + pid = fork(); + if (pid < 0) + ksft_exit_fail_msg("%s test: Failed to create new process\n", + test_name); + + if (pid == 0) + _exit(EXIT_SUCCESS); + + snprintf(buf, sizeof(buf), "/proc/%d", pid); + + pidfd = open(buf, O_DIRECTORY | O_CLOEXEC); + + (void)wait_for_pid(pid); + + if (pidfd < 0) + ksft_exit_fail_msg( + "%s test: Failed to open process file descriptor\n", + test_name); + + ret = sys_pidfd_send_signal(pidfd, 0, NULL, 0); + saved_errno = errno; + close(pidfd); + if (ret == 0) + ksft_exit_fail_msg( + "%s test: Managed to send signal to process even though it should have failed\n", + test_name); + + if (saved_errno != ESRCH) + ksft_exit_fail_msg( + "%s test: Expected to receive ESRCH as errno value but received %d instead\n", + test_name, saved_errno); + + ksft_test_result_pass("%s test: Failed to send signal as expected\n", + test_name); + return 0; +} + +/* + * Maximum number of cycles we allow. This is equivalent to PID_MAX_DEFAULT. + * If users set a higher limit or we have cycled PIDFD_MAX_DEFAULT number of + * times then we skip the test to not go into an infinite loop or block for a + * long time. + */ +#define PIDFD_MAX_DEFAULT 0x8000 + +static int test_pidfd_send_signal_recycled_pid_fail(void) +{ + int i, ret; + pid_t pid1; + const char *test_name = "pidfd_send_signal signal recycled pid"; + + if (!have_pidfd_send_signal) { + ksft_test_result_skip( + "%s test: pidfd_send_signal() syscall not supported\n", + test_name); + return 0; + } + + ret = unshare(CLONE_NEWPID); + if (ret < 0) { + if (errno == EPERM) { + ksft_test_result_skip("%s test: Unsharing pid namespace not permitted\n", + test_name); + return 0; + } + ksft_exit_fail_msg("%s test: Failed to unshare pid namespace\n", + test_name); + } + + ret = unshare(CLONE_NEWNS); + if (ret < 0) { + if (errno == EPERM) { + ksft_test_result_skip("%s test: Unsharing mount namespace not permitted\n", + test_name); + return 0; + } + ksft_exit_fail_msg("%s test: Failed to unshare mount namespace\n", + test_name); + } + + ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0); + if (ret < 0) + ksft_exit_fail_msg("%s test: Failed to remount / private\n", + test_name); + + /* pid 1 in new pid namespace */ + pid1 = fork(); + if (pid1 < 0) + ksft_exit_fail_msg("%s test: Failed to create new process\n", + test_name); + + if (pid1 == 0) { + char buf[256]; + pid_t pid2; + int pidfd = -1; + + (void)umount2("/proc", MNT_DETACH); + ret = mount("proc", "/proc", "proc", 0, NULL); + if (ret < 0) + _exit(PIDFD_ERROR); + + /* grab pid PID_RECYCLE */ + for (i = 0; i <= PIDFD_MAX_DEFAULT; i++) { + pid2 = fork(); + if (pid2 < 0) + _exit(PIDFD_ERROR); + + if (pid2 == 0) + _exit(PIDFD_PASS); + + if (pid2 == PID_RECYCLE) { + snprintf(buf, sizeof(buf), "/proc/%d", pid2); + ksft_print_msg("pid to recycle is %d\n", pid2); + pidfd = open(buf, O_DIRECTORY | O_CLOEXEC); + } + + if (wait_for_pid(pid2)) + _exit(PIDFD_ERROR); + + if (pid2 >= PID_RECYCLE) + break; + } + + /* + * We want to be as predictable as we can so if we haven't been + * able to grab pid PID_RECYCLE skip the test. + */ + if (pid2 != PID_RECYCLE) { + /* skip test */ + close(pidfd); + _exit(PIDFD_SKIP); + } + + if (pidfd < 0) + _exit(PIDFD_ERROR); + + for (i = 0; i <= PIDFD_MAX_DEFAULT; i++) { + char c; + int pipe_fds[2]; + pid_t recycled_pid; + int child_ret = PIDFD_PASS; + + ret = pipe2(pipe_fds, O_CLOEXEC); + if (ret < 0) + _exit(PIDFD_ERROR); + + recycled_pid = fork(); + if (recycled_pid < 0) + _exit(PIDFD_ERROR); + + if (recycled_pid == 0) { + close(pipe_fds[1]); + (void)read(pipe_fds[0], &c, 1); + close(pipe_fds[0]); + + _exit(PIDFD_PASS); + } + + /* + * Stop the child so we can inspect whether we have + * recycled pid PID_RECYCLE. + */ + close(pipe_fds[0]); + ret = kill(recycled_pid, SIGSTOP); + close(pipe_fds[1]); + if (ret) { + (void)wait_for_pid(recycled_pid); + _exit(PIDFD_ERROR); + } + + /* + * We have recycled the pid. Try to signal it. This + * needs to fail since this is a different process than + * the one the pidfd refers to. + */ + if (recycled_pid == PID_RECYCLE) { + ret = sys_pidfd_send_signal(pidfd, SIGCONT, + NULL, 0); + if (ret && errno == ESRCH) + child_ret = PIDFD_XFAIL; + else + child_ret = PIDFD_FAIL; + } + + /* let the process move on */ + ret = kill(recycled_pid, SIGCONT); + if (ret) + (void)kill(recycled_pid, SIGKILL); + + if (wait_for_pid(recycled_pid)) + _exit(PIDFD_ERROR); + + switch (child_ret) { + case PIDFD_FAIL: + /* fallthrough */ + case PIDFD_XFAIL: + _exit(child_ret); + case PIDFD_PASS: + break; + default: + /* not reached */ + _exit(PIDFD_ERROR); + } + + /* + * If the user set a custom pid_max limit we could be + * in the millions. + * Skip the test in this case. + */ + if (recycled_pid > PIDFD_MAX_DEFAULT) + _exit(PIDFD_SKIP); + } + + /* failed to recycle pid */ + _exit(PIDFD_SKIP); + } + + ret = wait_for_pid(pid1); + switch (ret) { + case PIDFD_FAIL: + ksft_exit_fail_msg( + "%s test: Managed to signal recycled pid %d\n", + test_name, PID_RECYCLE); + case PIDFD_PASS: + ksft_exit_fail_msg("%s test: Failed to recycle pid %d\n", + test_name, PID_RECYCLE); + case PIDFD_SKIP: + ksft_test_result_skip("%s test: Skipping test\n", test_name); + ret = 0; + break; + case PIDFD_XFAIL: + ksft_test_result_pass( + "%s test: Failed to signal recycled pid as expected\n", + test_name); + ret = 0; + break; + default /* PIDFD_ERROR */: + ksft_exit_fail_msg("%s test: Error while running tests\n", + test_name); + } + + return ret; +} + +static int test_pidfd_send_signal_syscall_support(void) +{ + int pidfd, ret; + const char *test_name = "pidfd_send_signal check for support"; + + pidfd = open("/proc/self", O_DIRECTORY | O_CLOEXEC); + if (pidfd < 0) + ksft_exit_fail_msg( + "%s test: Failed to open process file descriptor\n", + test_name); + + ret = sys_pidfd_send_signal(pidfd, 0, NULL, 0); + if (ret < 0) { + if (errno == ENOSYS) { + ksft_test_result_skip( + "%s test: pidfd_send_signal() syscall not supported\n", + test_name); + return 0; + } + ksft_exit_fail_msg("%s test: Failed to send signal\n", + test_name); + } + + have_pidfd_send_signal = true; + close(pidfd); + ksft_test_result_pass( + "%s test: pidfd_send_signal() syscall is supported. Tests can be executed\n", + test_name); + return 0; +} + +static void *test_pidfd_poll_exec_thread(void *priv) +{ + ksft_print_msg("Child Thread: starting. pid %d tid %ld ; and sleeping\n", + getpid(), syscall(SYS_gettid)); + ksft_print_msg("Child Thread: doing exec of sleep\n"); + + execl("/bin/sleep", "sleep", str(CHILD_THREAD_MIN_WAIT), (char *)NULL); + + ksft_print_msg("Child Thread: DONE. pid %d tid %ld\n", + getpid(), syscall(SYS_gettid)); + return NULL; +} + +static void poll_pidfd(const char *test_name, int pidfd) +{ + int c; + int epoll_fd = epoll_create1(EPOLL_CLOEXEC); + struct epoll_event event, events[MAX_EVENTS]; + + if (epoll_fd == -1) + ksft_exit_fail_msg("%s test: Failed to create epoll file descriptor " + "(errno %d)\n", + test_name, errno); + + event.events = EPOLLIN; + event.data.fd = pidfd; + + if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, pidfd, &event)) { + ksft_exit_fail_msg("%s test: Failed to add epoll file descriptor " + "(errno %d)\n", + test_name, errno); + } + + c = epoll_wait(epoll_fd, events, MAX_EVENTS, 5000); + if (c != 1 || !(events[0].events & EPOLLIN)) + ksft_exit_fail_msg("%s test: Unexpected epoll_wait result (c=%d, events=%x) ", + "(errno %d)\n", + test_name, c, events[0].events, errno); + + close(epoll_fd); + return; + +} + +static int child_poll_exec_test(void *args) +{ + pthread_t t1; + + ksft_print_msg("Child (pidfd): starting. pid %d tid %ld\n", getpid(), + syscall(SYS_gettid)); + pthread_create(&t1, NULL, test_pidfd_poll_exec_thread, NULL); + /* + * Exec in the non-leader thread will destroy the leader immediately. + * If the wait in the parent returns too soon, the test fails. + */ + while (1) + sleep(1); +} + +static void test_pidfd_poll_exec(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 child thread exec"; + + ksft_print_msg("Parent: pid: %d\n", getpid()); + pid = pidfd_clone(CLONE_PIDFD, &pidfd, child_poll_exec_test); + if (pid < 0) + ksft_exit_fail_msg("%s test: pidfd_clone failed (ret %d, errno %d)\n", + test_name, pid, errno); + + 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); +} + +static void *test_pidfd_poll_leader_exit_thread(void *priv) +{ + ksft_print_msg("Child Thread: starting. pid %d tid %ld ; and sleeping\n", + getpid(), syscall(SYS_gettid)); + sleep(CHILD_THREAD_MIN_WAIT); + ksft_print_msg("Child Thread: DONE. pid %d tid %ld\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 %ld\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); + /* Never reached, but appeases compiler thinking we should return. */ + exit(0); +} + +static void test_pidfd_poll_leader_exit(int use_waitpid) +{ + int pid, pidfd = 0; + int status, ret = 0; + 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); + + if (child_exit_secs == MAP_FAILED) + ksft_exit_fail_msg("%s test: mmap failed (errno %d)\n", + test_name, errno); + + ksft_print_msg("Parent: pid: %d\n", getpid()); + pid = pidfd_clone(CLONE_PIDFD, &pidfd, child_poll_leader_exit_test); + if (pid < 0) + ksft_exit_fail_msg("%s test: pidfd_clone failed (ret %d, errno %d)\n", + test_name, pid, errno); + + 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"); + } else { + /* + * This sleep tests for the case where if the child exits, and is in + * EXIT_ZOMBIE, but the thread group leader is non-empty, then the poll + * doesn't prematurely return even though there are active threads + */ + sleep(1); + poll_pidfd(test_name, pidfd); + } + + if (ret == pid) + ksft_print_msg("Parent: Child process waited for.\n"); + + time_t since_child_exit = time(NULL) - *child_exit_secs; + + ksft_print_msg("Time since child exit: %lu\n", since_child_exit); + + close(pidfd); + + if (since_child_exit < CHILD_THREAD_MIN_WAIT || + since_child_exit > 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); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(8); + + test_pidfd_poll_exec(0); + test_pidfd_poll_exec(1); + test_pidfd_poll_leader_exit(0); + test_pidfd_poll_leader_exit(1); + test_pidfd_send_signal_syscall_support(); + test_pidfd_send_signal_simple_success(); + test_pidfd_send_signal_exited_fail(); + test_pidfd_send_signal_recycled_pid_fail(); + + return ksft_exit_pass(); +} |