February 20, 2015 01:42 · Feb 20, 2015
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,23 @@
+#include <unistd.h>
+#include <mach/mach.h>
+#include <mach/mach_vm.h>
+#include <mach-o/dyld.h>
+
+int
+main (int argc, char * argv[])
+{
+  volatile char * library;
+  const mach_vm_size_t page_size = getpagesize ();
+  const mach_vm_size_t buffer_size = 3 * page_size;
+  char buffer[buffer_size];
+  mach_vm_size_t result_size;
+
+  library = (char *) _dyld_get_image_header (1);
+  mach_vm_protect (mach_task_self (), (mach_vm_address_t) (library + page_size), page_size, FALSE, VM_PROT_READ | VM_PROT_WRITE | VM_PROT_COPY | VM_PROT_EXECUTE);
+  library[page_size]++;
+  library[page_size]--;
+  result_size = 0;
+  mach_vm_read_overwrite (mach_task_self (), (mach_vm_address_t) library, buffer_size, (mach_vm_address_t) buffer, &result_size);
+
+  return 0;
+}