tools/testing/selftests/powerpc/math/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
  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
  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
  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
  82 int main(int argc, char *argv[])
  83 {
  84         return test_harness(test_syscall_fpu, "syscall_fpu");
  85
  86 }