//:: call :(scenario call_imm32) % Reg[ESP].u = 0x64; # op ModRM SIB displacement immediate e8 a0 00 00 00 # call function offset at 0x000000a0 # next EIP is 6 +run: call imm32 0x000000a0 +run: decrementing ESP to 0x00000060 +run: pushing value 0x00000006 +run: jumping to 0x000000a6 :(before "End Single-Byte Opcodes") case 0xe8: { // call imm32 relative to next EIP int32_t offset = imm32(); trace(2, "run") << "call imm32 0x" << HEXWORD << offset << end(); push(EIP); EIP += offset; trace(2, "run") << "jumping to 0x" << HEXWORD << EIP << end(); break; } //: :(scenario call_r32) % Reg[ESP].u = 0x64; % Reg[EBX].u = 0x000000a0; # op ModRM SIB displacement immediate ff d3 # call function offset at EBX (reg 3) # next EIP is 3 +run: call to effective address +run: effective address is reg 3 +run: decrementing ESP to 0x00000060 +run: pushing value 0x00000003 +run: jumping to 0x000000a3 :(before "End Op ff Subops") case 2: { // call function pointer at r/m32 trace(2, "run") << "call to effective address" << end(); int32_t* offset = effective_address(modrm); push(EIP); EIP += *offset; trace(2, "run") << "jumping to 0x" << HEXWORD << EIP << end(); break; } :(scenario call_mem_at_r32) % Reg[ESP].u = 0x64; % Reg[EBX].u = 0x10; % SET_WORD_IN_MEM(0x10, 0x000000a0); # op ModRM SIB displacement immediate ff 13 # call function offset at *EBX (reg 3) # next EIP is 3 +run: call to effective address +run: effective address is mem at address 0x10 (reg 3) +run: decrementing ESP to 0x00000060 +run: pushing value 0x00000003 +run: jumping to 0x000000a3 //:: ret :(scenario ret) % Reg[ESP].u = 0x60; % SET_WORD_IN_MEM(0x60, 0x00000010); # op ModRM SIB displacement immediate c3 +run: return +run: popping value 0x00000010 +run: jumping to 0x00000010 :(before "End Single-Byte Opcodes") case 0xc3: { // return from a call trace(2, "run") << "return" << end(); EIP = pop(); trace(2, "run") << "jumping to 0x" << HEXWORD << EIP << end(); break; }