1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <stdio.h>
#include <mach/mach.h>
#include <mach/mach_vm.h>
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"); // stop here in the signal handler
kern_return_t success
= mach_vm_protect(mach_task_self(), (mach_vm_address_t) g_int_ptr,
g_size, 0, VM_PROT_READ|VM_PROT_WRITE);
g_int_ptr[1] = 20;
}
int
main()
{
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(), (mach_vm_address_t) 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_int_ptr[1];
return local_value; // Break here to make sure we got past the signal handler
}
|
