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}
101