bitmap-feedback.md

How to use bitmap-feedback feature

This feature instruments the program to enable bitmap feedback.

Usage

$ fuzzuf-cc --features bitmap-feedback [options] <file>

Options

--bitmap-load-point arg

Specifies the timing for instrumentation. Default value is OptimizerLast.

arg	effect
OptimizerLast	Performs instrumentation after optimization
FullLinkTimeOptimizationLast	Performs instrumentation after Link Time Optimization (LTO)

--bitmap-instrumentation-method arg

Specifies the algorithm for calculating the index when changing the bitmap. Default value is HASHED_EDGE.

arg	effect
HASHED_EDGE	loc = (prev_loc >> 1) ^ cur_loc
NODE	loc = cur_loc

--bitmap-update-method arg

Specifies the algorithm for changing the bitmap. Default value is NAIVE.

arg	effect
NAIVE	bitmap[loc] = bitmap[loc] + 1
AVOID_ZERO	bitmap[loc] = bitmap[loc] + 1 + (bitmap[loc] + 1 == 0)
CAP_FF	bitmap[loc] = bitmap[loc] + (bitmap[loc] != 0xff)