I have a .so from an Android JNI/NDK application. Here are two of its sections:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al  .rel.plt REL 001c9034 1c9034 00c928 08 AI 3 11 4  .plt PROGBITS 001d595c 1d595c 012dd0 00 AX 0 0 4
Based on the Info parameter of
.rel.plt, I would expect the relocations it contains to affect the contents of the
.plt section. However, the addresses in the relocations are all to much higher addresses:
Relocation section '.rel.plt' at offset 0x1c9034 contains 6437 entries: Offset Info Type Sym. Value Symbol's Name 00e1bb6c 00000216 R_ARM_JUMP_SLOT 00000000 __cxa_atexit@LIBC 00e1bb70 00000116 R_ARM_JUMP_SLOT 00000000 __cxa_finalize@LIBC 00e1bb74 00000316 R_ARM_JUMP_SLOT 00a0f8c5 _Znwj 00e1bb78 00000416 R_ARM_JUMP_SLOT 00a0f941 _ZdlPv 00e1bb7c 00000516 R_ARM_JUMP_SLOT 00a1886d __gxx_personality_v0 00e1bb80 00000716 R_ARM_JUMP_SLOT 00000000 __stack_chk_fail@LIBC 00e1bb84 00000b16 R_ARM_JUMP_SLOT 009ed201 _ZNSt6__ndk16chrono12system_clock3nowEv
Those addresses fall into the range of the
.data sections. This is a shared object, so the offsets should be virtual address based rather than section based, and the ELF for the ARM Architecture says:
The ELF standard requires that the GOT-generating relocations of the PLT are emitted into a contiguous sub-range of the dynamic relocation section. That sub-range is denoted by the standard tags DT_JMPREL and DT_PLTRELSZ. The type of relocations (RELor RELA) is stored in the DT_PLTREL tag.
Am I misunderstanding what the offset of these relocations applies to? Or perhaps what "GOT-generating relocations" means?