>> ptrace can support this too. It can let sbrk/mmap through, but tell >> the usermode kernel as it does so. Or it can consult with the >> usermode kernel first, and then let them through in a possibly >> modified form. > I still don't see how this allows for regions shared between > usermode, user-space processes.
That's not difficult, but... > The user-space code in the shared processes would have to > periodically poll to see if any new shared regions were available to > it, or something -- ugh. ...making them appear asynchronously with respect to userland userspace's calls to userland kernel would, yes, be difficult. (Or anything else that lets the ptracer regain control; syscalls are just the most convenient such thing.) But is that important? Do we have cases now where new VM appears in a userspace's VM asynchronously with respect to syscalls it makes? If so, what can trigger the creation of such a thing? /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
