Class: OneGadget::Emulators::I386

Inherits:
X86 show all
Defined in:
lib/one_gadget/emulators/i386.rb

Overview

Emulator of amd64 instruction set.

Constant Summary

Constants inherited from X86

X86::COMPARES, X86::JCC, X86::SEGMENT_OPERAND

Constants inherited from Processor

Processor::ADDRESS_TYPES, Processor::CLOBBERED, Processor::NULLABLE_REQUIREMENTS, Processor::POINTER_REQUIREMENTS, Processor::TERMINAL_CALL_RE

Constants included from Conditional

Conditional::COMPARE_OPS, Conditional::NEGATE, Conditional::RELATION

Instance Attribute Summary

Attributes inherited from Processor

#bp, #pc, #refused_line, #registers, #sp

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from X86

#instructions, #process!

Methods inherited from Processor

#address_deref0?, #bp_based_stack, #closed_fds, #constraint_key, #constraints, #drop_implied_nonzero, #drop_restated_null, #get_corresponding_stack, instruction_table, #instructions, line_memo, #parse, #process, #process!, #reach_terminal_call, #render_constraint, #resolve_address, #setup_frame_pointer, #sp_based_stack, #terminal_call?

Methods included from Conditional

#branch_on_bit, #branch_on_compare, #branch_on_zero, #comparisons_on, #handle_compare, #mnemonic, #operand_str, #record_compare, #resolve_pending_branch, #satisfiable?, #value_str

Constructor Details

#initialize ⇒ I386

Instantiate an OneGadget::Emulators::I386 object.



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# File 'lib/one_gadget/emulators/i386.rb', line 18

def initialize
  super(OneGadget::ABI.i386, 'esp', 'ebp', 'eip')
end

Class Method Details

.bits ⇒ Object

Yap, bits.



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# File 'lib/one_gadget/emulators/i386.rb', line 12

def bits
  32
end

Instance Method Details

#argument(idx) ⇒ Lambda, Integer

Get function call arguments.

For i386 this is a little bit tricky. We need to fetch the stack slots reference to current 'esp' but not original 'esp'. So we need to evaluate the offset of current esp first.

Parameters:

  • idx (Integer) —

    The 0-based index of the argument.

Returns:

  • (Lambda, Integer) —

    The value on the stack slot holding the +idx+-th argument.



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# File 'lib/one_gadget/emulators/i386.rb', line 30

def argument(idx)
  cur_top = registers['esp'].evaluate('esp' => 0)
  sp_based_stack[cur_top + idx * 4]
end