Mechanism for re-writing an executable having mixed code and data

The method according to step 3, wherein the step of analyzing includes the step of analyzing the plurality of words to identify instructions by:

• selecting a known instruction;
• responsive to the known instruction not being a control flow transfer, fetching a next instruction in a sequence of the plurality of words relative to the known instruction;
• classifying the next instruction as an instruction by asserting the instruction flag in the corresponding entry of the data structure;
• and
• repeating the steps of fetching and classifying until the next instruction is a control transfer instruction.

The method according to step 4 further comprising the step of:

• decoding the next instruction to determine whether the instruction is a conditional branch instruction;
• responsive to the next instruction being a conditional branch instruction, locating each of the target words of the branch instruction from the plurality of words;
• and
• classifying each of the target words as instructions by asserting the instruction flags in the corresponding entries of the data structure.

The method according to step 4 further comprising the step of:

• decoding the next instruction to determine whether the instruction is a jump instruction or an unconditional branch instruction;
• responsive to the next instruction being a jump instruction or an unconditional branch instruction, locating the target of the jump instruction or the unconditional branch instruction in the plurality of words;
• and
• classifying the target of the jump instruction or an unconditional branch instruction as an instruction by asserting the instruction flag in the corresponding entry of the data structure.

A computer readable medium having a data structure stored thereon, the data structure comprising a plurality of entries corresponding to a plurality of words in an executable file, with each entry of the data structure further comprising:

• a flag for indicating whether a word in a corresponding location of the executable file is an instruction;
• a flag for indicating whether a word in a corresponding location of the executable file is a problem fall through;
• and
• a flag for indicating whether a word in a corresponding location of the executable file is a data word.