diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile
index deaf8073bc066..4b31c14f273c4 100644
--- a/tools/testing/selftests/pidfd/Makefile
+++ b/tools/testing/selftests/pidfd/Makefile
@@ -1,4 +1,4 @@
-CFLAGS += -g -I../../../../usr/include/
+CFLAGS += -g -I../../../../usr/include/ -lpthread
TEST_GEN_PROGS := pidfd_test
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 5bae1792e3d63..9929dc6fa2d6f 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -4,18 +4,47 @@
#include <errno.h>
#include <fcntl.h>
#include <linux/types.h>
+#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdio.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 "../kselftest.h"
+#define str(s) _str(s)
+#define _str(s) #s
+#define CHILD_THREAD_MIN_WAIT 3 /* seconds */
+
+#define MAX_EVENTS 5
+#ifndef __NR_pidfd_send_signal
+#define __NR_pidfd_send_signal 424
+#endif
+
+#ifndef CLONE_PIDFD
+#define CLONE_PIDFD 0x00001000
+#endif
+
+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 inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
unsigned int flags)
{
@@ -368,11 +397,192 @@ static int test_pidfd_send_signal_syscall_support(void)
return 0;
}
+static void *test_pidfd_poll_exec_thread(void *priv)
+{
+ ksft_print_msg("Child Thread: starting. pid %d tid %d ; 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 %d\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 %d\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;
+ pthread_t t1;
+ 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 %d ; and sleeping\n",
+ getpid(), syscall(SYS_gettid));
+ sleep(CHILD_THREAD_MIN_WAIT);
+ ksft_print_msg("Child Thread: DONE. pid %d tid %d\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 %d\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);
+}
+
+static void test_pidfd_poll_leader_exit(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 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(4);
+ 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();