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    Subjectmmap_min_addr/SECURITY_DEFAULT_MMAP_MIN_ADDR suggested values
    Hi,
    The config help for SECURITY_DEFAULT_MMAP_MIN_ADDR suggests 65536
    as a 'reasonable' value for x86 and the original mmap_min_addr
    patches suggested that 'something like 64k' was a safe value that
    wouldn't affect most programs.

    Where does this 64k value come from? A number of distros seem
    to have followed this advice and have it set to 64k; but is there
    really any likely benefit of having it larger than PAGE_SIZE say?

    I ask because I have an ancient program that maps stuff at 8k; the
    general advice of stuff on the net seems to be to set this limit
    to 0 if people have problems (I'm just lowering it to 4k),
    but I was thinking perhaps using a lower default value would be more
    secure since less people would take the easy answer and just turn the
    feature off altogether.

    Dave

    --
    -----Open up your eyes, open up your mind, open up your code -------
    / Dr. David Alan Gilbert | Running GNU/Linux on Alpha,68K| Happy \
    \ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex /
    \ _________________________|_____ http://www.treblig.org |_______/


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