Package ghidra.program.model.correlate

Class HashedFunctionAddressCorrelation

  • All Implemented Interfaces:
    FunctionAddressCorrelation, ListingAddressCorrelation
    public class HashedFunctionAddressCorrelation
extends java.lang.Object
implements FunctionAddressCorrelation
    Correlator to construct a 1-1 map between the Instructions of two similar Functions. Matching is performed via a greedy algorithm that looks for sequences (n-grams) of Instructions that are similar between the two Functions. Similarity of two sequences is determined by comparing hashes generated by the HashCalculator object. 1) Potential sequences and their hashes are generated for both functions (see HashStore). 2) Sequences are pulled from the HashStore based on the uniqueness of a potential match and on the size of the sequence. 3) If a unique match is found between sequences, it is extended in either direction as far as possible, as constrained by HashCalculator and the containing basic-blocks. 4) The matching Instruction pairs are put in the final map and removed from further sequence lists to allow other potential matches to be considered. 5) Sequences with no corresponding match are also removed from consideration. 6) Sequences are limited to a single basic-block, and the algorithm is basic-block aware. Once a match establishes a correspondence between a pair of basic blocks, the algorithm uses that information to further narrow in on and disambiguate matching sequences. 7) If a particular sequence has matches that are not unique, the algorithm tries to disambiguate the potential matches by looking at parent/child relationships of the containing basic-blocks. (see DisambiguateStrategy) 8) Multiple passes are attempted, each time the set of potential sequences is completely regenerated, varying the range of sequence sizes for which a match is attempted and other hash parameters. This allows matches discovered by earlier passes to disambiguate sequences in later passes.

    • Constructor Detail

    • Method Detail

      • getSecondProgram

        public Program getSecondProgram()
        Description copied from interface: ListingAddressCorrelation
        Gets the program containing the second set of addresses. This program may be different from or the same as the first program.
        Specified by:
        getSecondProgram in interface ListingAddressCorrelation
        Returns:
        the program for the second set of addresses.

      • getTotalInstructionsInFirst

        public int getTotalInstructionsInFirst()
        Gets the total number of instructions that are in the first function.
        Returns:
        the first function's instruction count.

      • getTotalInstructionsInSecond

        public int getTotalInstructionsInSecond()
        Gets the total number of instructions that are in the second function.
        Returns:
        the second function's instruction count.

      • numMatchedInstructionsInFirst

        public int numMatchedInstructionsInFirst()
        Determines the number of instructions from the first function that match an instruction in the second function.
        Returns:
        the number of instructions in the first function that have matches.

      • numMatchedInstructionsInSecond

        public int numMatchedInstructionsInSecond()
        Determines the number of instructions from the second function that match an instruction in the first function.
        Returns:
        the number of instructions in the second function that have matches.

      • getUnmatchedInstructionsInFirst

        public java.util.List<Instruction> getUnmatchedInstructionsInFirst()
        Determines the number of instructions from the first function that do not match an instruction in the second function.
        Returns:
        the number of instructions in the first function without matches.

      • getUnmatchedInstructionsInSecond

        public java.util.List<Instruction> getUnmatchedInstructionsInSecond()
        Determines the number of instructions from the second function that do not match an instruction in the first function.
        Returns:
        the number of instructions in the second function without matches.

      • getFirstToSecondIterator

        public java.util.Iterator<java.util.Map.Entry<Address,​Address>> getFirstToSecondIterator()
        Gets an iterator of the matching addresses from the first function to the second.
        Returns:
        the iterator

      • getAddressInSecond

        public Address getAddressInSecond​(Address addressInFirst)
        Description copied from interface: ListingAddressCorrelation
        Determine the address from the second set that matches the specified address in the first set.
        Specified by:
        getAddressInSecond in interface ListingAddressCorrelation
        Parameters:
        addressInFirst - the address in the first address set.
        Returns:
        the matching address in the second set or null if a match couldn't be determined.

      • getAddressInFirst

        public Address getAddressInFirst​(Address addressInSecond)
        Description copied from interface: ListingAddressCorrelation
        Determine the address from the first set that matches the specified address in the second set.
        Specified by:
        getAddressInFirst in interface ListingAddressCorrelation
        Parameters:
        addressInSecond - the address in the second address set.
        Returns:
        the matching address in the first set or null if a match couldn't be determined.