On Wed, 14 Feb 2024 10:42:57 -0800 Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > On 2/14/24 10:22, Petr Tesařík wrote: > > Anyway, in the long term I would like to work on gradual decomposition > > of the kernel into a core part and many self-contained components. > > Sandbox mode is a useful tool to enforce isolation. > > I'd want to see at least a few examples of how this decomposition would > work and how much of a burden it is on each site that deployed it. Got it. Are you okay with a couple of examples to illustrate the concept? Because if you want patches that have been acked by the respective maintainers, it somehow becomes a chicken-and-egg kind of problem... > But I'm skeptical that this could ever work. Ring-0 execution really is > special and it's _increasingly_ so. Think of LASS or SMAP or SMEP. I have just answered a similar concern by hpa. In short, I don't think these features are relevant, because by definition sandbox mode does not share anything with user mode address space. > We're even seeing hardware designers add hardware security defenses to > ring-0 that are not applied to ring-3. > > In other words, ring-3 isn't just a deprivileged ring-0, it's more > exposed to attacks. > > > I'd rather fail fast than maintain hundreds of patches in an > > out-of-tree branch before submitting (and failing anyway). > > I don't see any remotely feasible path forward for this approach. I can live with such decision. But first, I want to make sure that the concept has been understood correctly. So far, at least some concerns suggest an understanding that is not quite accurate. Is this sandbox idea a bit too much out-of-the-box? Petr T
