Hi, Le mercredi 18 juillet 2018 à 10:26 -0400, Theodore Y. Ts'o a écrit : > On Wed, Jul 18, 2018 at 09:22:13AM +0200, Yann Droneaud wrote: > > > > The text message should explain this is only relevant during > > initialization / early boot. > > > > The config option name should state this. > > There are other workarounds for hangs that happen after > initialization / early boot, yes. They are of varying levels of > quality / safely, but that's neither here nor there. > > However, enabling config option means that the CRNG will be > initialized with potentially information available to the CPU > manufacturer and/or Nation States, and this persists *after* > initialization / early boot. So to say, "we're perfectly safe after > we leave initialization / early boot" is not true. > Sure, but, AFAICT, RDRAND is already in use through arch_get_random_*() functions when CONFIG_ARCH_RANDOM is enabled. >From an outside PoV, there's a conflict: why one would want its kernel to use CPU hwrng if one has purposely disabled CONFIG_RANDOM_TRUST_CPU ? > So I'd much rather make it clear that we are trusting the CPU > manufacturer far more than just during early boot. > Then, should CONFIG_ARCH_RANDOM depends on CONFIG_RANDOM_TRUST_CPU (on x86 at least) ? Regards. -- Yann Droneaud OPTEYA
