#include <stdlib.h>
#include <sys/mman.h>
#include <stdio.h>
+#include <mach/mach.h>
+#include <mach/mach_vm.h>
-int g_ints[] = {10, 20, 30, 40, 50, 60};
+int *g_int_ptr = NULL;
+size_t g_size = 10*sizeof(int);
void
saction_handler(int signo, siginfo_t info, void *baton) {
- printf("Got into handler.\n");
- mprotect(g_ints, sizeof(g_ints), PROT_READ|PROT_WRITE); // stop here in the signal handler
- g_ints[0] = 20;
+ printf("Got into handler.\n"); // stop here in the signal handler
+ kern_return_t success
+ = mach_vm_protect(mach_task_self(), g_int_ptr,
+ g_size, 0, VM_PROT_READ|VM_PROT_WRITE);
+ g_int_ptr[1] = 20;
}
int
main()
{
- mprotect(g_ints, 10*sizeof(int) , PROT_NONE);
+ kern_return_t vm_result = vm_allocate(mach_task_self(), &g_int_ptr, g_size, VM_FLAGS_ANYWHERE);
+ for (int i = 0; i < 10; i++)
+ g_int_ptr[i] = i * 10;
+
+ vm_result = mach_vm_protect(mach_task_self(), g_int_ptr, g_size, 0, VM_PROT_NONE);
struct sigaction my_action;
sigemptyset(&my_action.sa_mask);
my_action.sa_handler = (void (*)(int)) saction_handler;
my_action.sa_flags = SA_SIGINFO;
sigaction(SIGBUS, &my_action, NULL); // Stop here to get things going.
- int local_value = g_ints[1];
+ int local_value = g_int_ptr[1];
return local_value; // Break here to make sure we got past the signal handler
}