libMangoHud_shim.so exports extra symbols such as eh_hash_elf, __dlsym, get_proc_address #1667
Description
Describe the bug
libMangoHud_shim.so is a LD_PRELOAD module, so every symbol that it exports will "interpose" symbols of the same name in any other library, and be called instead of the other implementation.
It looks as though it is exporting more symbols than it strictly needs to, which risks crashes or other badness.
List relevant hardware/software information
- Linux Distribution: anything recent, tested on Arch
- MangoHud version: 0.8.1-1 or git dc30950
- GPU: AMD Vega
To Reproduce
objdump -T -x /path/to/libMangoHud_shim.so
Expected behavior
Only the symbols that MangoHud is intentionally replacing are exported, namely those declared with CREATE_FWD_VOID or CREATE_FWD and hooked with ADD_HOOK:
glXSwapBufferseglGetDisplayeglGetPlatformDisplayeglSwapBuffersglXSwapBuffersMscOMLglXGetProcAddressglXGetProcAddressARBeglGetProcAddress
plus any that are handled non-generically:
dlsym- (others?)
Actual behavior
These symbols are exported:
DYNAMIC SYMBOL TABLE:
...
0000000000006018 g DO .bss 0000000000000008 Base __dlsym
0000000000003aa0 g DF .text 00000000000000ab Base dlsym
0000000000002810 g DF .text 0000000000000059 Base eh_hash_elf
0000000000003730 g DF .text 000000000000008a Base real_dlsym
00000000000037c0 g DF .text 000000000000004d Base glXSwapBuffers
00000000000029e0 g DF .text 0000000000000041 Base eh_hash_gnu
0000000000002f30 g DF .text 0000000000000111 Base eh_set_rel
0000000000003860 g DF .text 0000000000000065 Base eglGetPlatformDisplay
0000000000002610 g DF .text 00000000000001aa Base eh_init_obj
0000000000003810 g DF .text 0000000000000050 Base eglGetDisplay
0000000000003b50 g DF .text 0000000000000014 Base get_proc_address
0000000000003b70 g DF .text 000000000000008e Base eh_iterate_callback
0000000000003a50 g DF .text 0000000000000050 Base eglGetProcAddress
0000000000003920 g DF .text 0000000000000081 Base glXSwapBuffersMscOML
0000000000003a00 g DF .text 0000000000000050 Base glXGetProcAddressARB
0000000000002c70 g DF .text 000000000000000a Base eh_iterate_sym
0000000000003590 g DF .text 00000000000001a0 Base real_dlopen
0000000000003050 g DF .text 000000000000013a Base eh_iterate_rela_plt
0000000000002550 g DF .text 000000000000004b Base eh_iterate_obj
00000000000025a0 g DF .text 0000000000000066 Base eh_check_addr
0000000000002e30 g DF .text 00000000000000ff Base eh_set_rel_plt
0000000000002c80 g DF .text 000000000000009a Base eh_find_next_dyn
0000000000003190 g DF .text 000000000000012a Base eh_iterate_rel_plt
00000000000038d0 g DF .text 000000000000004f Base eglSwapBuffers
00000000000032c0 g DF .text 0000000000000121 Base eh_iterate_rel
0000000000002bd0 g DF .text 000000000000009a Base eh_find_sym
0000000000002870 g DF .text 0000000000000164 Base eh_find_sym_hash
00000000000039b0 g DF .text 0000000000000050 Base glXGetProcAddress
00000000000024e0 g DF .text 000000000000006e Base eh_find_callback
0000000000002a30 g DF .text 0000000000000192 Base eh_find_sym_gnu_hash
0000000000002d20 g DF .text 000000000000010f Base eh_set_rela_plt
00000000000027c0 g DF .text 000000000000004b Base eh_find_obj
00000000000033f0 g DF .text 000000000000000f Base eh_destroy_obj
0000000000006020 g DO .bss 0000000000000008 Base __dlopen
and could interpose in front of any game or library code that uses the same naming convention, potentially for an incompatible function.