From aa88dea2270f685349ab7b92169600452fe73b62 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 2 Jul 2012 07:52:16 -0400 Subject: random: make 'add_interrupt_randomness()' do something sane commit 775f4b297b780601e61787b766f306ed3e1d23eb upstream. 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 Reported-by: Eric Wustrow Reported-by: Nadia Heninger Reported-by: Zakir Durumeric Reported-by: J. Alex Halderman Signed-off-by: Linus Torvalds Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- drivers/mfd/ab3100-core.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/mfd') diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c index a20e1c4..c0befd3 100644 --- a/drivers/mfd/ab3100-core.c +++ b/drivers/mfd/ab3100-core.c @@ -408,8 +408,6 @@ static irqreturn_t ab3100_irq_handler(int irq, void *data) u32 fatevent; int err; - add_interrupt_randomness(irq); - err = ab3100_get_register_page_interruptible(ab3100, AB3100_EVENTA1, event_regs, 3); if (err) -- cgit v1.1