Instruction exploitation through loader late fix-up
AssigneeInternational Business Machines Corporation
InventorMike S. Fulton
Life of this patent
Estimating the term…
Abstract
A method, computer program product, and data processing system for substituting a candidate instruction in application code being loaded during load time. Responsive to identifying the candidate instruction, a determination is made whether a hardware facility of the data processing system is present to execute the candidate instruction. If the hardware facility is absent from the data processing system, the candidate instruction is substituted with a second set of instructions.
Claims12
A computer program product for use in a data processing system, the computer program product comprising a computer-readable storage computer medium having computer usable program code for instruction substitution in an application code of an application being loaded during load time, the computer usable program code comprising:
- computer usable program code for, identifying during the load time whether a particular instruction is a candidate instruction for replacement by using a fix-up information generated during compile time;
- computer usable program code for, responsive to identifying the candidate instruction, determining whether the hardware facility of the data processing system is present to execute the candidate instruction;
- and
- computer usable program code for, responsive to a determination that the hardware facility is absent from the data processing system, substituting the candidate instruction with a second set of instructions during the load time wherein the second set of instructions is different from the candidate instruction and configured to be executed with absence of the hardware facility.
A data processing system comprising:
- at least one processor;
- a bus coupled to the at least one processor;
- a computer-usable medium coupled to the bus, wherein the computer-usable medium contains a set of instructions for substituting a candidate instruction with a second set of instructions, wherein the at least one processor executes the set of instructions to:
- identify by using a fix-up information generated during compile time whether a particular instruction is a candidate instruction for replacement in a code of an application being loaded during load time;
- responsive to identifying the candidate instruction, determine whether a hardware facility of the data processing system is present to execute the candidate instruction;
- and
- responsive to a determination that the hardware facility is absent from the data processing system, substitute the candidate instruction with a second set of instructions during the load time wherein the second set of instructions is different from the candidate instruction and configured to be executed with absence of the hardware facility.
Dependencies are inferred from the claim text.