Incorrect Behaviour: Arm64 CopyLdrLiteral for non-SIMD inlines Pointer Read

[Sewer56]

Describe the bug

In the following detours code,

Detours/src/disasm.cpp

Lines 4241 to 4251 in 4b8c659

	else if (decoded.s.FpNeon == 0)
	{
	UINT64 value = 0;
	switch (decoded.s.Size)
	{
	case 0: value = *(ULONG*)pTarget; break;
	case 1: value = *(UINT64*)pTarget; break;
	case 2: value = *(LONG*)pTarget; break;
	}
	EmitMovImmediate(pDstInst, decoded.s.Rt, value);
	}

which rewrites LDR Literal, the value of a PC relative address is directly inlined into the register.

i.e. Detours transforms it into a sequence of MOVZ + MOVK.

This is problematic if the value behind the PC relative address changes. For example, if the relative address points into the .data segment in order to read/write a global variable; and the value of the variable changes, Detours' rewritten code will no longer insert the correct value into the register as it has inlined the old value.

Expected behavior

A read of PC relative address should not be inlined, as the value behind this offset is not guaranteed to be constant.

Additional context

I'm building a cross platform, multi architecture hooking library [big WIP]; and I found detours' source to be pretty invaluable as a reference for code rewriting.

This is just a small thing I noticed while working on code rewriting on my end while referencing detours.