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digitalmars.D.bugs - [Issue 13562] New: [Enh] add permute[=seed] command line argument to


          Issue ID: 13562
           Summary: [Enh] add permute[=seed] command line argument to dmd
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: DMD
          Assignee: nobody puremagic.com
          Reporter: bugzilla digitalmars.com

Return-Oriented-Programming (ROP) is a common attack method that malware uses
to exploit buffer overflows:


It relies on code having predictable contents and being in predictable

The compiler often makes potayto-potahto decisions when generating code. By
optionally providing a random value to the compiler, it can use that to toss a
coin for the decision, making the generated code slightly different - different
enough to defeat many ROP attacks.

Perturbations can be:

    changing the stack layout of locals

    changing the order of register selection

    changing the scheduling order of instructions

    weights given to loop variables

    instruction selection



    -perturb=seed    // use seed to guide the compiler's coin toss
    -perturb         // have the compiler generate its own seed, likely by
                     // using the clock. -v will cause this value to be printed
    default          // use a seed value of 0, causing the same behavior the
                     // compiler has now

Using this can also shake out compiler bugs by "fuzz" testing of different
paths through the compiler. It can help isolate stack corruption code bugs by
helping find a more reproducible test case.

This switch can be particularly useful for those who are willing to build their
apps from source, so that their executable will be different from anybody
else's built from the identical source.

It shouldn't be hard to implement.

Oct 01 2014