1 files changed, 271 insertions, 0 deletions
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c
new file mode 100644
index 000000000000..7079f8eef792
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_wait.c
@@ -0,0 +1,271 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "pidfd.h"
+#include "../kselftest.h"
+
+#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr)))
+
+static pid_t sys_clone3(struct clone_args *args)
+{
+	return syscall(__NR_clone3, args, sizeof(struct clone_args));
+}
+
+static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options,
+		      struct rusage *ru)
+{
+	return syscall(__NR_waitid, which, pid, info, options, ru);
+}
+
+static int test_pidfd_wait_simple(void)
+{
+	const char *test_name = "pidfd wait simple";
+	int pidfd = -1, status = 0;
+	pid_t parent_tid = -1;
+	struct clone_args args = {
+		.parent_tid = ptr_to_u64(&parent_tid),
+		.pidfd = ptr_to_u64(&pidfd),
+		.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
+		.exit_signal = SIGCHLD,
+	};
+	int ret;
+	pid_t pid;
+	siginfo_t info = {
+		.si_signo = 0,
+	};
+
+	pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+	if (pidfd < 0)
+		ksft_exit_fail_msg("%s test: failed to open /proc/self %s\n",
+				   test_name, strerror(errno));
+
+	pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+	if (pid == 0)
+		ksft_exit_fail_msg(
+			"%s test: succeeded to wait on invalid pidfd %s\n",
+			test_name, strerror(errno));
+	close(pidfd);
+	pidfd = -1;
+
+	pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC);
+	if (pidfd == 0)
+		ksft_exit_fail_msg("%s test: failed to open /dev/null %s\n",
+				   test_name, strerror(errno));
+
+	pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+	if (pid == 0)
+		ksft_exit_fail_msg(
+			"%s test: succeeded to wait on invalid pidfd %s\n",
+			test_name, strerror(errno));
+	close(pidfd);
+	pidfd = -1;
+
+	pid = sys_clone3(&args);
+	if (pid < 0)
+		ksft_exit_fail_msg("%s test: failed to create new process %s\n",
+				   test_name, strerror(errno));
+
+	if (pid == 0)
+		exit(EXIT_SUCCESS);
+
+	pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+	if (pid < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to wait on process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	if (!WIFEXITED(info.si_status) || WEXITSTATUS(info.si_status))
+		ksft_exit_fail_msg(
+			"%s test: unexpected status received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+	close(pidfd);
+
+	if (info.si_signo != SIGCHLD)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_signo, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_code != CLD_EXITED)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_code, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_pid != parent_tid)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_pid, parent_tid, pidfd,
+			strerror(errno));
+
+	ksft_test_result_pass("%s test: Passed\n", test_name);
+	return 0;
+}
+
+static int test_pidfd_wait_states(void)
+{
+	const char *test_name = "pidfd wait states";
+	int pidfd = -1, status = 0;
+	pid_t parent_tid = -1;
+	struct clone_args args = {
+		.parent_tid = ptr_to_u64(&parent_tid),
+		.pidfd = ptr_to_u64(&pidfd),
+		.flags = CLONE_PIDFD | CLONE_PARENT_SETTID,
+		.exit_signal = SIGCHLD,
+	};
+	int ret;
+	pid_t pid;
+	siginfo_t info = {
+		.si_signo = 0,
+	};
+
+	pid = sys_clone3(&args);
+	if (pid < 0)
+		ksft_exit_fail_msg("%s test: failed to create new process %s\n",
+				   test_name, strerror(errno));
+
+	if (pid == 0) {
+		kill(getpid(), SIGSTOP);
+		kill(getpid(), SIGSTOP);
+		exit(EXIT_SUCCESS);
+	}
+
+	ret = sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to wait on WSTOPPED process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	if (info.si_signo != SIGCHLD)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_signo, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_code != CLD_STOPPED)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_code, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_pid != parent_tid)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_pid, parent_tid, pidfd,
+			strerror(errno));
+
+	ret = sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to send signal to process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	ret = sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to wait WCONTINUED on process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	if (info.si_signo != SIGCHLD)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_signo, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_code != CLD_CONTINUED)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_code, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_pid != parent_tid)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_pid, parent_tid, pidfd,
+			strerror(errno));
+
+	ret = sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to wait on WUNTRACED process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	if (info.si_signo != SIGCHLD)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_signo, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_code != CLD_STOPPED)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_code, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_pid != parent_tid)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_pid, parent_tid, pidfd,
+			strerror(errno));
+
+	ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to send SIGKILL to process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+	if (ret < 0)
+		ksft_exit_fail_msg(
+			"%s test: failed to wait on WEXITED process with pid %d and pidfd %d: %s\n",
+			test_name, parent_tid, pidfd, strerror(errno));
+
+	if (info.si_signo != SIGCHLD)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_signo, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_code != CLD_KILLED)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_code, parent_tid, pidfd,
+			strerror(errno));
+
+	if (info.si_pid != parent_tid)
+		ksft_exit_fail_msg(
+			"%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n",
+			test_name, info.si_pid, parent_tid, pidfd,
+			strerror(errno));
+
+	close(pidfd);
+
+	ksft_test_result_pass("%s test: Passed\n", test_name);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	ksft_print_header();
+	ksft_set_plan(2);
+
+	test_pidfd_wait_simple();
+	test_pidfd_wait_states();
+
+	return ksft_exit_pass();
+}