• Emese Revfy's avatar
    gcc-plugins: Add latent_entropy plugin · 38addce8
    Emese Revfy authored
    This adds a new gcc plugin named "latent_entropy". It is designed to
    extract as much possible uncertainty from a running system at boot time as
    possible, hoping to capitalize on any possible variation in CPU operation
    (due to runtime data differences, hardware differences, SMP ordering,
    thermal timing variation, cache behavior, etc).
    
    At the very least, this plugin is a much more comprehensive example for
    how to manipulate kernel code using the gcc plugin internals.
    
    The need for very-early boot entropy tends to be very architecture or
    system design specific, so this plugin is more suited for those sorts
    of special cases. The existing kernel RNG already attempts to extract
    entropy from reliable runtime variation, but this plugin takes the idea to
    a logical extreme by permuting a global variable based on any variation
    in code execution (e.g. a different value (and permutation function)
    is used to permute the global based on loop count, case statement,
    if/then/else bra...
    38addce8
page_alloc.c 202 KB