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 
18 extern int test_fpu(double *darray, pid_t *pid);
19 
20 double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
21 		     1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
22 		     2.1};
23 
syscall_fpu(void)24 int syscall_fpu(void)
25 {
26 	pid_t fork_pid;
27 	int i;
28 	int ret;
29 	int child_ret;
30 	for (i = 0; i < 1000; i++) {
31 		/* test_fpu will fork() */
32 		ret = test_fpu(darray, &fork_pid);
33 		if (fork_pid == -1)
34 			return -1;
35 		if (fork_pid == 0)
36 			exit(ret);
37 		waitpid(fork_pid, &child_ret, 0);
38 		if (ret || child_ret)
39 			return 1;
40 	}
41 
42 	return 0;
43 }
44 
test_syscall_fpu(void)45 int test_syscall_fpu(void)
46 {
47 	/*
48 	 * Setup an environment with much context switching
49 	 */
50 	pid_t pid2;
51 	pid_t pid = fork();
52 	int ret;
53 	int child_ret;
54 	FAIL_IF(pid == -1);
55 
56 	pid2 = fork();
57 	/* Can't FAIL_IF(pid2 == -1); because already forked once */
58 	if (pid2 == -1) {
59 		/*
60 		 * Couldn't fork, ensure test is a fail
61 		 */
62 		child_ret = ret = 1;
63 	} else {
64 		ret = syscall_fpu();
65 		if (pid2)
66 			waitpid(pid2, &child_ret, 0);
67 		else
68 			exit(ret);
69 	}
70 
71 	ret |= child_ret;
72 
73 	if (pid)
74 		waitpid(pid, &child_ret, 0);
75 	else
76 		exit(ret);
77 
78 	FAIL_IF(ret || child_ret);
79 	return 0;
80 }
81 
main(int argc,char * argv[])82 int main(int argc, char *argv[])
83 {
84 	return test_harness(test_syscall_fpu, "syscall_fpu");
85 
86 }
87