Messages in this thread | | | Date | Fri, 22 Apr 2022 01:40:25 +0200 | From | "Jason A. Donenfeld" <> | Subject | Re: [PATCH v2] random: avoid mis-detecting a slow counter as a cycle counter |
| |
Hi Eric,
Thanks. This looks better.
On Thu, Apr 21, 2022 at 04:31:52PM -0700, Eric Biggers wrote: > Therefore, increase the number of counter comparisons from 1 to 3, to > greatly reduce the rate of false positive cycle counter detections. > + for (i = 0; i < 3; i++) { > + unsigned long entropy = random_get_entropy();
Wondering: why do you do 3 comparisons rather than 2? What does 3 get you that 2 doesn't already? I thought the only real requirement was that in the event where (a)!=(b), (b) is read as meaningfully close as possible to when the counter changes.
Jason
| |