xref: /linux/tools/testing/selftests/powerpc/math/fpu_syscall.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2015, Cyril Bur, IBM Corp.
4  *
5  * This test attempts to see if the FPU registers change across a syscall (fork).
6  */
7 
8 #include <stdio.h>
9 #include <unistd.h>
10 #include <sys/syscall.h>
11 #include <sys/time.h>
12 #include <sys/types.h>
13 #include <sys/wait.h>
14 #include <stdlib.h>
15 
16 #include "utils.h"
17 #include "fpu.h"
18 
19 extern int test_fpu(double *darray, pid_t *pid);
20 
21 double darray[32];
22 
23 int syscall_fpu(void)
24 {
25 	pid_t fork_pid;
26 	int i;
27 	int ret;
28 	int child_ret;
29 
30 	randomise_darray(darray, ARRAY_SIZE(darray));
31 
32 	for (i = 0; i < 1000; i++) {
33 		/* test_fpu will fork() */
34 		ret = test_fpu(darray, &fork_pid);
35 		if (fork_pid == -1)
36 			return -1;
37 		if (fork_pid == 0)
38 			exit(ret);
39 		waitpid(fork_pid, &child_ret, 0);
40 		if (ret || child_ret)
41 			return 1;
42 	}
43 
44 	return 0;
45 }
46 
47 int test_syscall_fpu(void)
48 {
49 	/*
50 	 * Setup an environment with much context switching
51 	 */
52 	pid_t pid2;
53 	pid_t pid = fork();
54 	int ret;
55 	int child_ret;
56 	FAIL_IF(pid == -1);
57 
58 	pid2 = fork();
59 	/* Can't FAIL_IF(pid2 == -1); because already forked once */
60 	if (pid2 == -1) {
61 		/*
62 		 * Couldn't fork, ensure test is a fail
63 		 */
64 		child_ret = ret = 1;
65 	} else {
66 		ret = syscall_fpu();
67 		if (pid2)
68 			waitpid(pid2, &child_ret, 0);
69 		else
70 			exit(ret);
71 	}
72 
73 	ret |= child_ret;
74 
75 	if (pid)
76 		waitpid(pid, &child_ret, 0);
77 	else
78 		exit(ret);
79 
80 	FAIL_IF(ret || child_ret);
81 	return 0;
82 }
83 
84 int main(int argc, char *argv[])
85 {
86 	return test_harness(test_syscall_fpu, "syscall_fpu");
87 
88 }
89