• David S. Miller's avatar
    sparc64: Sharpen address space randomization calculations. · 5a0efea0
    David S. Miller authored
    A recent patch to the x86 randomization code caused me to take
    a quick look at what we do on sparc64, and in doing so I noticed
    that we sometimes calculate a non-page-aligned randomization value
    and stick it into mmap_base.
    
    I also noticed that since I copied the logic over from PowerPC,
    the powerpc code has tweaked the randomization ranges in ways that
    would benefit us as well.
    
    For one thing, we should allow up to at least 8MB of randomization
    otherwise huge-page regions when HPAGE_SIZE is 4MB never randomize
    at all.
    
    And on the 64-bit side we were using up to 4GB.  Tone it down to
    1GB as 4GB can result in a lot of address space wastage.
    
    Finally, make sure all computations are unsigned.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    5a0efea0
sys_sparc_64.c 18.9 KB