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Theodore Ts'o authored
We've been moving away from add_interrupt_randomness() for various reasons: it's too expensive to do on every interrupt, and flooding the CPU with interrupts could theoretically cause bogus floods of entropy from a somewhat externally controllable source. This solves both problems by limiting the actual randomness addition to just once a second or after 64 interrupts, whicever comes first. During that time, the interrupt cycle data is buffered up in a per-cpu pool. Also, we make sure the the nonblocking pool used by urandom is initialized before we start feeding the normal input pool. This assures that /dev/urandom is returning unpredictable data as soon as possible. (Based on an original patch by Linus, but significantly modified by tytso.) Tested-by:
Eric Wustrow <ewust@umich.edu> Reported-by:
Eric Wustrow <ewust@umich.edu> Reported-by:
Nadia Heninger <nadiah@cs.ucsd.edu> Reported-by:
Zakir Durumeric <zakir@umich.edu> Reported-by: J. Alex Halderman <jhalderm@umich.edu>. Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
"Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
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