none/tests/freebsd/usrstack.c

   1 #include <sys/types.h>
   2 #include <sys/sysctl.h>
   3 #include <unistd.h>
   4 #include <stdarg.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7
   8 int main(void)
   9 {
  10    int stack_variable = 1;
  11    unsigned long v1;
  12    unsigned long v2;
  13    int name[] = {CTL_KERN, KERN_USRSTACK};
  14    size_t len = sizeof(unsigned long);
  15
  16    if (sysctlbyname("kern.usrstack", &v1, &len, NULL, 0) < 0) {
  17       perror("sysctlbyname failed:");
  18       exit(-1);
  19    }
  20
  21    if (sysctl(name, 2, &v2, &len, NULL, 0) < 0) {
  22       perror("sysctl failed:");
  23       exit(-1);
  24    }
  25
  26    if (v1 == v2) {
  27        printf("OK 1\n");
  28    } else {
  29        printf("FAIL usrstack different\n");
  30        printf("v1 %lx v2 %lx\n", v1, v2);
  31    }
  32
  33
  34    /* the purpose of this is to check that the sysctl isn't
  35       returning the host stack. I expec the difference to be less than 0x1000 */
  36    if (v1 - (unsigned long)&stack_variable > 0x2000U) {
  37       printf("FAIL usrstack fishy\n");
  38       printf("v1 %lx stack_variable %p diff %lx\n", v1, &stack_variable,  v1 - (unsigned long)&stack_variable);
  39    } else {
  40       printf("OK 2\n");
  41    }
  42 }
  43