tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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}