Extension of Research on Security as a Service for VMs in IaaS Platform

Algorithm 2

GuestCodeRelocResv.

	Input: hdr, sechdrs, relsec, symindex,strtab, guest_load_addr
	Output: Relocated resolved code in memory
	rel ⟵ hdr + sechdrs[relsec].sh_offset;
	for i ⟵ 0 to sechdrs[relsec].sh_size/sizeof(^∗rel) do
	target_sec ⟵ sechdrs[relsec].sh_info;
	loc ⟵ hdr + sechdrs[target_sec].sh_offset + rel[i].r_offset;
	fake_loc⟵guest_load_addr +
	sech drs[target_sec].sh_offset + rel[i].r_offset;
	sym ⟵ hdr + sechdrs[symindex].sh_offset +
	ELF_R_SYM(rel[i].r_info);
	symname ⟵ strtab + sym->st_name;
	val ⟵ sym->st_value + rel[i].r_addend;
	rel_type ⟵ ELF_R_TYPE(rel[i].r_info);
	switch rel_type do
	case rel_type = R_X86_64_64^∗(u64^∗)loc ⟵ val;
	case rel_type = R_X86_64_32^∗(u32^∗)loc ⟵ val;
	case rel_type = R_X86_64_32S^∗(s32^∗)loc ⟵ val;
	case rel_type = R_X86_64_PC32 val ⟵ val-(u64)fake_loc; ^∗(u32^∗)loc ⟵ val;
	otherwise
	Output Unknown;
	endsw
	endsw
	end