/* SPDX-License-Identifier: GPL-2.0 */

#define _GNU_SOURCE
#include <errno.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <sys/syscall.h>
#include <sys/wait.h>

#include "kselftest.h"
#include "clone3_selftests.h"

static void nop_handler(int signo)
{
}

static int wait_for_pid(pid_t pid)
{
        int status, ret;

again:
        ret = waitpid(pid, &status, 0);
        if (ret == -1) {
                if (errno == EINTR)
                        goto again;

                return -1;
        }

        if (!WIFEXITED(status))
                return -1;

        return WEXITSTATUS(status);
}

static void test_clone3_clear_sighand(void)
{
        int ret;
        pid_t pid;
        struct __clone_args args = {};
        struct sigaction act;

        /*
         * Check that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
         * exclusive.
         */
        args.flags |= CLONE_CLEAR_SIGHAND | CLONE_SIGHAND;
        args.exit_signal = SIGCHLD;
        pid = sys_clone3(&args, sizeof(args));
        if (pid > 0)
                ksft_exit_fail_msg(
                        "clone3(CLONE_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");

        act.sa_handler = nop_handler;
        ret = sigemptyset(&act.sa_mask);
        if (ret < 0)
                ksft_exit_fail_msg("%s - sigemptyset() failed\n",
                                   strerror(errno));

        act.sa_flags = 0;

        /* Register signal handler for SIGUSR1 */
        ret = sigaction(SIGUSR1, &act, NULL);
        if (ret < 0)
                ksft_exit_fail_msg(
                        "%s - sigaction(SIGUSR1, &act, NULL) failed\n",
                        strerror(errno));

        /* Register signal handler for SIGUSR2 */
        ret = sigaction(SIGUSR2, &act, NULL);
        if (ret < 0)
                ksft_exit_fail_msg(
                        "%s - sigaction(SIGUSR2, &act, NULL) failed\n",
                        strerror(errno));

        /* Check that CLONE_CLEAR_SIGHAND works. */
        args.flags = CLONE_CLEAR_SIGHAND;
        pid = sys_clone3(&args, sizeof(args));
        if (pid < 0)
                ksft_exit_fail_msg("%s - clone3(CLONE_CLEAR_SIGHAND) failed\n",
                                   strerror(errno));

        if (pid == 0) {
                ret = sigaction(SIGUSR1, NULL, &act);
                if (ret < 0)
                        exit(EXIT_FAILURE);

                if (act.sa_handler != SIG_DFL)
                        exit(EXIT_FAILURE);

                ret = sigaction(SIGUSR2, NULL, &act);
                if (ret < 0)
                        exit(EXIT_FAILURE);

                if (act.sa_handler != SIG_DFL)
                        exit(EXIT_FAILURE);

                exit(EXIT_SUCCESS);
        }

        ret = wait_for_pid(pid);
        if (ret)
                ksft_exit_fail_msg(
                        "Failed to clear signal handler for child process\n");

        ksft_test_result_pass("Cleared signal handlers for child process\n");
}

int main(int argc, char **argv)
{
        ksft_print_header();
        ksft_set_plan(1);
        test_clone3_supported();

        test_clone3_clear_sighand();

        ksft_exit_pass();
}