Re: [PATCH] ELF: implement AT_RANDOM for future glibc use

From: Roland McGrath
Date: Mon Oct 06 2008 - 19:59:19 EST


What mmap randomization and stack randomization actually use is
get_random_int(), not get_random_bytes(). This is one of those weaker
flavors seeded occasionally from the real entropy pool. (As is, it's not a
good choice for getting 16 bytes of random at once, since it usually
returns the same 4 bytes each time when called 4 times in quick succession.)

What glibc wants is some bits with a strength of randomness chosen by the
kernel, and not to worry about the details. I think the strength applied
to mmap and stack randomization is good enough for AT_RANDOM.


Thanks,
Roland
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