Date: Wed, 19 Sep 2012 19:28:36 +0100 From: RW <rwmaillists@googlemail.com> To: freebsd-security@freebsd.org Subject: Re: Collecting entropy from device_attach() times. Message-ID: <20120919192836.3a60cdfd@gumby.homeunix.com> In-Reply-To: <20120918211422.GA1400@garage.freebsd.pl> References: <20120918211422.GA1400@garage.freebsd.pl>
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On Tue, 18 Sep 2012 23:14:22 +0200 Pawel Jakub Dawidek wrote: > Hi. >=20 > The patch is here: >=20 > http://people.freebsd.org/~pjd/patches/harvest_device_attach.patch >=20 > Comments? >=20 + attachtime =3D get_cyclecount() - attachtime; the above line is redundant since random_harvest() already contains a call to get_cyclecount(). On Wed, 19 Sep 2012 17:28:46 +0200 Dag-Erling Sm=F8rgrav wrote: > You can't rely on the existence of a TSC. I would suggest using the > fractional part of binuptime instead. get_cyclecount() is supposed to be platform independent and should fall-back to nanotime(9) if TSC or equivalent is absent.=20
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