linux/tools/testing/selftests/powerpc/math/fpu_syscall.c
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   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
  18extern int test_fpu(double *darray, pid_t *pid);
  19
  20double 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
  24int 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
  45int 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
  82int main(int argc, char *argv[])
  83{
  84        return test_harness(test_syscall_fpu, "syscall_fpu");
  85
  86}
  87