tools/testing/selftests/powerpc/math/fpu_syscall.c

   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
  22 extern int test_fpu(double *darray, pid_t *pid);
  23
  24 double 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
  28 int 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
  49 int 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
  86 int main(int argc, char *argv[])
  87 {
  88         return test_harness(test_syscall_fpu, "syscall_fpu");
  89
  90 }