1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2022 ARM Limited.
  4 * Original author: Mark Brown <broonie@kernel.org>
  5 */
  6
  7// SPDX-License-Identifier: GPL-2.0-only
  8
  9#include <linux/sched.h>
 10#include <linux/wait.h>
 11
 12#include "kselftest.h"
 13
 14#define EXPECTED_TESTS 1
 15
 16int fork_test(void);
 17int verify_fork(void);
 18
 19/*
 20 * If we fork the value in the parent should be unchanged and the
 21 * child should start with the same value.  This is called from the
 22 * fork_test() asm function.
 23 */
 24int fork_test_c(void)
 25{
 26	pid_t newpid, waiting;
 27	int child_status, parent_result;
 28
 29	newpid = fork();
 30	if (newpid == 0) {
 31		/* In child */
 32		if (!verify_fork()) {
 33			ksft_print_msg("ZA state invalid in child\n");
 34			exit(0);
 35		} else {
 36			exit(1);
 37		}
 38	}
 39	if (newpid < 0) {
 40		ksft_print_msg("fork() failed: %d\n", newpid);
 41
 42		return 0;
 43	}
 44
 45	parent_result = verify_fork();
 46	if (!parent_result)
 47		ksft_print_msg("ZA state invalid in parent\n");
 48
 49	for (;;) {
 50		waiting = waitpid(newpid, &child_status, 0);
 51
 52		if (waiting < 0) {
 53			if (errno == EINTR)
 54				continue;
 55			ksft_print_msg("waitpid() failed: %d\n", errno);
 56			return 0;
 57		}
 58		if (waiting != newpid) {
 59			ksft_print_msg("waitpid() returned wrong PID\n");
 60			return 0;
 61		}
 62
 63		if (!WIFEXITED(child_status)) {
 64			ksft_print_msg("child did not exit\n");
 65			return 0;
 66		}
 67
 68		return WEXITSTATUS(child_status) && parent_result;
 69	}
 70}
 71
 72int main(int argc, char **argv)
 73{
 74	int ret, i;
 75
 76	ksft_print_header();
 77	ksft_set_plan(EXPECTED_TESTS);
 78
 79	ksft_print_msg("PID: %d\n", getpid());
 80
 81	/*
 82	 * This test is run with nolibc which doesn't support hwcap and
 83	 * it's probably disproportionate to implement so instead check
 84	 * for the default vector length configuration in /proc.
 85	 */
 86	ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);
 87	if (ret >= 0) {
 88		ksft_test_result(fork_test(), "fork_test\n");
 89
 90	} else {
 91		ksft_print_msg("SME not supported\n");
 92		for (i = 0; i < EXPECTED_TESTS; i++) {
 93			ksft_test_result_skip("fork_test\n");
 94		}
 95	}
 96
 97	ksft_finished();
 98
 99	return 0;
100}