On Tue, Nov 12, 2013 at 01:03:07AM +0100, Hannes Frederic Sowa wrote: > On Mon, Nov 11, 2013 at 08:43:57AM -0500, Theodore Ts'o wrote: > > On Mon, Nov 11, 2013 at 12:20:34PM +0100, Daniel Borkmann wrote: > > > From: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> > > > > > > The Tausworthe PRNG is initialized at late_initcall time. At that time the > > > entropy pool serving get_random_bytes is not filled sufficiently. This > > > patch adds an additional reseeding step as soon as the nonblocking pool > > > gets marked as initialized. > > > > > > On some machines it might be possible that late_initcall gets called after > > > the pool has been initialized. In this situation we won't reseed again. > > > > > > (A call to prandom_seed_late blocks later invocations of early reseed > > > attempts.) > > > > > > Joint work with Daniel Borkmann. > > > > Acked-by: "Theodore Ts'o" <tytso@xxxxxxx> > > > > I wasn't cc'ed on the full series (I didn't see the 0/3 or the 4/6 > > messages) but there are two other things that you might want to > > consider. > > > > 1) I'm pretty sure, but it would be good to get netdev confirmation, > > that the call to get_random_bytes() in > > net/mac80211/rc80211_minstrel.c's init_sample_table() can be replaced > > by calls to prandom_u32(). > > Would make sense. I added wireless-devel to confirm. > > [...] > [ 0.673260] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.674024] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.675012] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.676032] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.677020] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.678011] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [ 0.679011] random: rc80211_minstrel_ht_init+0x47/0xaa get_random_bytes called with 3 bits of entropy available > [...] > > In total 80 calls to get_random_bytes. > It is already 8 times what rc80211_minstrel_ht_init uses. If you could apply on top of: http://marc.info/?l=linux-wireless&m=138392850030987&w=2 although Johannes has not yet agreed/applied this. Karl -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
