Fix get instr normalization

[Ninja3047]

Attempting to patch an PIE ARM thumb binary (attached) produces the following error.

Traceback (most recent call last):
  File "/workdir/tests/test_arm.py", line 75, in test_insert_instruction_pie_patch
    self.run_one(
  File "/workdir/tests/test_arm.py", line 192, in run_one
    p.apply_patches()
  File "/workdir/src/patcherex2/patcherex.py", line 57, in apply_patches
    patch.apply(self)
  File "/workdir/src/patcherex2/patches/instruction_patches.py", line 51, in apply
    p.utils.insert_trampoline_code(
  File "/workdir/src/patcherex2/components/utils/utils.py", line 18, in insert_trampoline_code
    assert force_insert or self.is_valid_insert_point(
  File "/workdir/src/patcherex2/components/utils/utils.py", line 103, in is_valid_insert_point
    return self.get_instrs_to_be_moved(addr) is not None
  File "/workdir/src/patcherex2/components/utils/utils.py", line 95, in get_instrs_to_be_moved
    if not self.is_movable_instruction(insn_addr):
  File "/workdir/src/patcherex2/components/utils/utils.py", line 108, in is_movable_instruction
    asm = self.p.disassembler.disassemble(insn, addr, is_thumb=is_thumb)[0]
IndexError: list index out of range

printf_pie.zip

This PR fixes this issue by making sure to check for the thumbness first before denormalizing the address and adds a small unit test that tests for this issue.

[DennyDai]

@Ninja3047 Thank you for the fix! It looks good to me. Please ignore the private-test that's actually a CI issue. Could you provide the source code and compiler flags so that we may reuse it for other architectures in the future? Just pasting them here as a reply would be great.

[Ninja3047]

@Ninja3047 Thank you for the fix! It looks good to me. Please ignore the private-test that's actually a CI issue. Could you provide the source code and compiler flags so that we may reuse it for other architectures in the future? Just pasting them here as a reply would be great.

FROM ubuntu:22.04

RUN apt-get update && apt-get install -y gcc-12-arm-linux-gnueabihf

#include <stdio.h>

int main(int argc, char* argv[]) {
    printf("%s", "Hi");
    return 0;
}

compile flags are the default ubuntu compiler flags

arm-linux-gnueabihf-gcc-12 -o printf_pie printf_pie.c