On Fri, Oct 19, 2018 at 08:36:45AM -0700, Kees Cook wrote: > On Fri, Oct 19, 2018 at 4:24 AM, Will Deacon <will.deacon@xxxxxxx> wrote: > > FWIW: I think we should be entertaining a prctl() interface to use a new > > key on a per-thread basis. Obviously, this would need to be used with care > > (e.g. you'd fork(); use the prctl() and then you'd better not return from > > the calling function!). > > > > Assuming we want this (Kees -- I was under the impression that everything in > > Android would end up with the same key otherwise?), then the question is > > do we want: > > > > - prctl() get/set operations for the key, or > > - prctl() set_random_key operation, or > > - both of the above? > > > > Part of the answer to that may lie in the requirements of CRIU, where I > > strongly suspect they need explicit get/set operations, although these > > could be gated on CONFIG_CHECKPOINT_RESTORE=y. > > Oh CRIU. Yikes. I'd like the get/set to be gated by the CONFIG, yes. > No reason to allow explicit access to the key (and selected algo) if > we don't have to. Makes sense. > As for per-thread or not, having a "pick a new key now" prctl() sounds > good, but I'd like to have an eye toward having it just be "automatic" > on clone(). I thought about that too, but we're out of clone() flags afaict and there's no arch hook in there. We could add yet another clone syscall, but yuck (and I reckon viro would kill us). Or are you saying that we could infer the behaviour from the existing set of flags? Will _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
