// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2022 ARM Limited.
 * Original author: Mark Brown <broonie@kernel.org>
 */

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

#include <linux/sched.h>
#include <linux/wait.h>

#include "kselftest.h"

#define EXPECTED_TESTS 1

int fork_test(void);
int verify_fork(void);

/*
 * If we fork the value in the parent should be unchanged and the
 * child should start with the same value.  This is called from the
 * fork_test() asm function.
 */
int fork_test_c(void)
{
        pid_t newpid, waiting;
        int child_status, parent_result;

        newpid = fork();
        if (newpid == 0) {
                /* In child */
                if (!verify_fork()) {
                        ksft_print_msg("ZA state invalid in child\n");
                        exit(0);
                } else {
                        exit(1);
                }
        }
        if (newpid < 0) {
                ksft_print_msg("fork() failed: %d\n", newpid);

                return 0;
        }

        parent_result = verify_fork();
        if (!parent_result)
                ksft_print_msg("ZA state invalid in parent\n");

        for (;;) {
                waiting = waitpid(newpid, &child_status, 0);

                if (waiting < 0) {
                        if (errno == EINTR)
                                continue;
                        ksft_print_msg("waitpid() failed: %d\n", errno);
                        return 0;
                }
                if (waiting != newpid) {
                        ksft_print_msg("waitpid() returned wrong PID\n");
                        return 0;
                }

                if (!WIFEXITED(child_status)) {
                        ksft_print_msg("child did not exit\n");
                        return 0;
                }

                return WEXITSTATUS(child_status) && parent_result;
        }
}

int main(int argc, char **argv)
{
        int ret, i;

        ksft_print_header();
        ksft_set_plan(EXPECTED_TESTS);

        ksft_print_msg("PID: %d\n", getpid());

        /*
         * This test is run with nolibc which doesn't support hwcap and
         * it's probably disproportionate to implement so instead check
         * for the default vector length configuration in /proc.
         */
        ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);
        if (ret >= 0) {
                ksft_test_result(fork_test(), "fork_test\n");

        } else {
                ksft_print_msg("SME not supported\n");
                for (i = 0; i < EXPECTED_TESTS; i++) {
                        ksft_test_result_skip("fork_test\n");
                }
        }

        ksft_finished();

        return 0;
}