Method and apparatus for modifying relocatable object code files and monitoring programs

A computer program produce that generates machine instructions including memory access monitoring instructions, comprising:

• computer code that receives as input a first set of machine instructions, said first set of machine instructions being specific to a computer processor with each machine instruction of said first set corresponding to an instruction executable by said computer processor, said first set of machine instructions including a memory access instruction;
• computer code that generates a second set of machine instructions that are memory monitoring instructions, said memory monitoring instructions checking a memory status of a memory location accessed by said memory access instruction in conjunction with execution of said memory access instruciton, said memory status including an allocated state and an unallocated state;
• and
• a computer readable medium that stores said computer codes.

A computer system the generates machine instructions including memory access monitoring instructions, comprising:

• a processor;
• and
• a storage medium coupled to said processor, said storage medium storing computer code including:
• computer code that receives as input a first set of machine instructions, said first set of machine instructions being specific to a computer processor with each machine instruction of said first set corresponding to an instruciton executable by said computer processor, said first set of machine instructions including a memory access instruction;
• and
• computer code that generates a second set of machine instructions from said first set of machine instructions having additional machine instructions that are memory monitoring instructions, said memory monitoring instructions checking a memory status of a memory location accessed by said memory access instruction in conjunction with execution of said memory access instruction, said memory status includes an allocated state and an unallocated state.

A computer implemented method for generating machine instructions including memory access instructions checked by memory monitoring instructions, said method comprising the steps of:

• receiving as input the first set of machine instructions, said first set of machine instructions being specific to a computer processor with each machine instruction of said first set corresponding to an instruction executable by said computer processor, said first set of machine instructions including a memory access instruction;
• generating a second set of machine instructions from said first set of machine instructions having additional machine instructions that are memory monitoring instructions, said memory monitoring instructions checking a memory status of a memory location accessed by said memory access instruction in conjunction with execution of said memory access instruction, said memory status including an allocated state and an unallocated state;
• signaling an error if said memory status indicates said memory location is in an unallocated state when accessed by said memory access instruction, said error indicating a memory-access related fault is present in said first set of machine instructions;
• and
• generating a third set of machine instructions that do not include said memory-access related fault if said error is signaled.

A computer program on a computer storage medium including memory access instructions checked by memory monitoring instructions, said computer program generated by the steps of:

• receiving as input a first set of machine isntrcutions, said first set of machine instructions being specific to a computer processor with each machine instruction of said first set corresponding to an instruction executable by said computer processor, said first set of machine instructions including a memory access instruction'
• generating a second set of machine instructions from said first set of machine instructions having additional machine instructions that are memory monitoring instructions, said memory monitoring instructions checking a memory status of a memory location accessed by said memory access instruction in conjunction with execution of said memory access instruciton, said memory status including an allocated state and unallocated state;
• signaling an error if said memory status indicates said memory location is in an unallocated state when accessed by said memory access instruction, said error indicating a memory-access related fault is present in said first set of machine instructions;
• generating a third set of machine instruction that do not include said memory-access related fault if said error is signaled;
• and
• storing said computer program on said computer storage medium, said computer program including executable instructions corresponding to said third set of machine instructions.