fpu_syscall.c

 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
19extern int test_fpu(double *darray, pid_t *pid);
20
21double darray[32];
22
23int 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
47int 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
84int main(int argc, char *argv[])
85{
86	return test_harness(test_syscall_fpu, "syscall_fpu");
87
88}