LXR linux/tools/testing/selftests/powerpc/math/fpu

   1/*
   2 * Copyright 2015, Cyril Bur, IBM Corp.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License
   6 * as published by the Free Software Foundation; either version
   7 * 2 of the License, or (at your option) any later version.
   8 *
   9 * This test attempts to see if the FPU registers change across a syscall (fork).
  10 */
  11
  12#include <stdio.h>
  13#include <unistd.h>
  14#include <sys/syscall.h>
  15#include <sys/time.h>
  16#include <sys/types.h>
  17#include <sys/wait.h>
  18#include <stdlib.h>
  19
  20#include "utils.h"
  21
  22extern int test_fpu(double *darray, pid_t *pid);
  23
  24double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
  25                     1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
  26                     2.1};
  27
  28int syscall_fpu(void)
  29{
  30        pid_t fork_pid;
  31        int i;
  32        int ret;
  33        int child_ret;
  34        for (i = 0; i < 1000; i++) {
  35                /* test_fpu will fork() */
  36                ret = test_fpu(darray, &fork_pid);
  37                if (fork_pid == -1)
  38                        return -1;
  39                if (fork_pid == 0)
  40                        exit(ret);
  41                waitpid(fork_pid, &child_ret, 0);
  42                if (ret || child_ret)
  43                        return 1;
  44        }
  45
  46        return 0;
  47}
  48
  49int test_syscall_fpu(void)
  50{
  51        /*
  52         * Setup an environment with much context switching
  53         */
  54        pid_t pid2;
  55        pid_t pid = fork();
  56        int ret;
  57        int child_ret;
  58        FAIL_IF(pid == -1);
  59
  60        pid2 = fork();
  61        /* Can't FAIL_IF(pid2 == -1); because already forked once */
  62        if (pid2 == -1) {
  63                /*
  64                 * Couldn't fork, ensure test is a fail
  65                 */
  66                child_ret = ret = 1;
  67        } else {
  68                ret = syscall_fpu();
  69                if (pid2)
  70                        waitpid(pid2, &child_ret, 0);
  71                else
  72                        exit(ret);
  73        }
  74
  75        ret |= child_ret;
  76
  77        if (pid)
  78                waitpid(pid, &child_ret, 0);
  79        else
  80                exit(ret);
  81
  82        FAIL_IF(ret || child_ret);
  83        return 0;
  84}
  85
  86int main(int argc, char *argv[])
  87{
  88        return test_harness(test_syscall_fpu, "syscall_fpu");
  89
  90}
  91