ronnie
2022-10-14 1504bb53e29d3d46222c0b3ea994fc494b48e153
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
#include <android/dlext.h>
#include <dlfcn.h>
#include <jni.h>
#include <stdlib.h>
 
extern "C" void text_before_start_of_gap() {}
char end_of_gap[0x1000];
 
extern "C" void* get_inner() {
  android_dlextinfo info = {};
  info.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
 
  char* start_of_gap =
      reinterpret_cast<char*>(reinterpret_cast<uintptr_t>(text_before_start_of_gap) & ~0xfffull) +
      0x1000;
  info.reserved_addr = start_of_gap;
  info.reserved_size = end_of_gap - start_of_gap;
 
  void *handle = android_dlopen_ext("libsegment_gap_inner.so", RTLD_NOW, &info);
  if (!handle) {
    __builtin_trap();
  }
 
  return dlsym(handle, "inner");
}