xref: /aosp_15_r20/bionic/tests/libs/segment_gap_outer.cpp (revision 8d67ca893c1523eb926b9080dbe4e2ffd2a27ba1)
1 #include <android/dlext.h>
2 #include <dlfcn.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 
text_before_start_of_gap()6 extern "C" void __attribute__((section(".custom_text"))) text_before_start_of_gap() {}
7 char __attribute__((section(".custom_bss"))) end_of_gap[0x1000];
8 
get_inner()9 extern "C" void* get_inner() {
10   android_dlextinfo info = {};
11   info.flags = ANDROID_DLEXT_RESERVED_ADDRESS;
12 
13   char* start_of_gap =
14       reinterpret_cast<char*>(
15           (reinterpret_cast<uintptr_t>(text_before_start_of_gap) &
16            ~(sysconf(_SC_PAGESIZE) - 1)) + sysconf(_SC_PAGESIZE));
17   info.reserved_addr = start_of_gap;
18   info.reserved_size = end_of_gap - start_of_gap;
19 
20   void *handle = android_dlopen_ext("libsegment_gap_inner.so", RTLD_NOW, &info);
21   if (!handle) {
22     __builtin_trap();
23   }
24 
25   return dlsym(handle, "inner");
26 }
27