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authorTheodore Ts'o <tytso@mit.edu>2012-07-02 07:52:16 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-07-14 20:17:28 -0400
commit775f4b297b780601e61787b766f306ed3e1d23eb (patch)
treee97e21669f0719636ccac0219f617bad6a0e8b54 /include/linux/random.h
parent74feec5dd83d879368c1081aec5b6a1cb6dd7ce2 (diff)
random: make 'add_interrupt_randomness()' do something sane
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
Diffstat (limited to 'include/linux/random.h')
-rw-r--r--include/linux/random.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/random.h b/include/linux/random.h
index 8f74538c96db..6ef39d7f2db1 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -52,7 +52,7 @@ extern void rand_initialize_irq(int irq);
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value);
-extern void add_interrupt_randomness(int irq);
+extern void add_interrupt_randomness(int irq, int irq_flags);
extern void get_random_bytes(void *buf, int nbytes);
void generate_random_uuid(unsigned char uuid_out[16]);