xref: /openbmc/linux/tools/testing/selftests/arm64/fp/za-fork.c (revision b97d6790d03b763eca08847a9a5869a4291b9f9a)
1212b0426SMark Brown // SPDX-License-Identifier: GPL-2.0-only
2212b0426SMark Brown /*
3212b0426SMark Brown  * Copyright (C) 2022 ARM Limited.
4212b0426SMark Brown  * Original author: Mark Brown <broonie@kernel.org>
5212b0426SMark Brown  */
6212b0426SMark Brown 
7212b0426SMark Brown // SPDX-License-Identifier: GPL-2.0-only
8212b0426SMark Brown 
9212b0426SMark Brown #include <linux/sched.h>
10212b0426SMark Brown #include <linux/wait.h>
11212b0426SMark Brown 
12266679ffSMark Brown #include "kselftest.h"
13266679ffSMark Brown 
14212b0426SMark Brown #define EXPECTED_TESTS 1
15212b0426SMark Brown 
16212b0426SMark Brown int fork_test(void);
17212b0426SMark Brown int verify_fork(void);
18212b0426SMark Brown 
19212b0426SMark Brown /*
20212b0426SMark Brown  * If we fork the value in the parent should be unchanged and the
21212b0426SMark Brown  * child should start with the same value.  This is called from the
22212b0426SMark Brown  * fork_test() asm function.
23212b0426SMark Brown  */
fork_test_c(void)24212b0426SMark Brown int fork_test_c(void)
25212b0426SMark Brown {
26212b0426SMark Brown 	pid_t newpid, waiting;
27212b0426SMark Brown 	int child_status, parent_result;
28212b0426SMark Brown 
29212b0426SMark Brown 	newpid = fork();
30212b0426SMark Brown 	if (newpid == 0) {
31212b0426SMark Brown 		/* In child */
32212b0426SMark Brown 		if (!verify_fork()) {
33266679ffSMark Brown 			ksft_print_msg("ZA state invalid in child\n");
34212b0426SMark Brown 			exit(0);
35212b0426SMark Brown 		} else {
36212b0426SMark Brown 			exit(1);
37212b0426SMark Brown 		}
38212b0426SMark Brown 	}
39212b0426SMark Brown 	if (newpid < 0) {
40266679ffSMark Brown 		ksft_print_msg("fork() failed: %d\n", newpid);
41266679ffSMark Brown 
42212b0426SMark Brown 		return 0;
43212b0426SMark Brown 	}
44212b0426SMark Brown 
45212b0426SMark Brown 	parent_result = verify_fork();
46212b0426SMark Brown 	if (!parent_result)
47266679ffSMark Brown 		ksft_print_msg("ZA state invalid in parent\n");
48212b0426SMark Brown 
49212b0426SMark Brown 	for (;;) {
50212b0426SMark Brown 		waiting = waitpid(newpid, &child_status, 0);
51212b0426SMark Brown 
52212b0426SMark Brown 		if (waiting < 0) {
53212b0426SMark Brown 			if (errno == EINTR)
54212b0426SMark Brown 				continue;
55266679ffSMark Brown 			ksft_print_msg("waitpid() failed: %d\n", errno);
56212b0426SMark Brown 			return 0;
57212b0426SMark Brown 		}
58212b0426SMark Brown 		if (waiting != newpid) {
59266679ffSMark Brown 			ksft_print_msg("waitpid() returned wrong PID\n");
60212b0426SMark Brown 			return 0;
61212b0426SMark Brown 		}
62212b0426SMark Brown 
63212b0426SMark Brown 		if (!WIFEXITED(child_status)) {
64266679ffSMark Brown 			ksft_print_msg("child did not exit\n");
65212b0426SMark Brown 			return 0;
66212b0426SMark Brown 		}
67212b0426SMark Brown 
68212b0426SMark Brown 		return WEXITSTATUS(child_status) && parent_result;
69212b0426SMark Brown 	}
70212b0426SMark Brown }
71212b0426SMark Brown 
main(int argc,char ** argv)72212b0426SMark Brown int main(int argc, char **argv)
73212b0426SMark Brown {
74212b0426SMark Brown 	int ret, i;
75212b0426SMark Brown 
76266679ffSMark Brown 	ksft_print_header();
77266679ffSMark Brown 	ksft_set_plan(EXPECTED_TESTS);
78212b0426SMark Brown 
79266679ffSMark Brown 	ksft_print_msg("PID: %d\n", getpid());
80212b0426SMark Brown 
81212b0426SMark Brown 	/*
82212b0426SMark Brown 	 * This test is run with nolibc which doesn't support hwcap and
83212b0426SMark Brown 	 * it's probably disproportionate to implement so instead check
84212b0426SMark Brown 	 * for the default vector length configuration in /proc.
85212b0426SMark Brown 	 */
86212b0426SMark Brown 	ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);
87212b0426SMark Brown 	if (ret >= 0) {
88*fbb41cf2SMark Brown 		ksft_test_result(fork_test(), "fork_test\n");
89212b0426SMark Brown 
90212b0426SMark Brown 	} else {
91266679ffSMark Brown 		ksft_print_msg("SME not supported\n");
92212b0426SMark Brown 		for (i = 0; i < EXPECTED_TESTS; i++) {
93266679ffSMark Brown 			ksft_test_result_skip("fork_test\n");
94266679ffSMark Brown 		}
95212b0426SMark Brown 	}
96212b0426SMark Brown 
97266679ffSMark Brown 	ksft_finished();
98212b0426SMark Brown 
99212b0426SMark Brown 	return 0;
100212b0426SMark Brown }
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