On Tue, Jan 23, 2024 at 4:59 PM Elizabeth Figura <zfigura@xxxxxxxxxxxxxxx> wrote: > > ntsync uses a misc device as the simplest and least intrusive uAPI interface. > > Each file description on the device represents an isolated NT instance, intended > to correspond to a single NT virtual machine. If I understand this text right, and if I understood the code right, you're saying that each open instance of the device represents an entire universe of NT synchronization objects, and no security or isolation is possible between those objects. For single-process use, this seems fine. But fork() will be a bit odd (although NT doesn't really believe in fork, so maybe this is fine). Except that NT has *named* semaphores and such. And I'm pretty sure I've written GUI programs that use named synchronization objects (IIRC they were events, and this was a *very* common pattern, regularly discussed in MSDN, usenet, etc) to detect whether another instance of the program is running. And this all works on real Windows because sessions have sufficiently separated namespaces, and the security all works out about as any other security on Windows, etc. But implementing *that* on top of this file-description-plus-integer-equals-object will be fundamentally quite subject to one buggy program completely clobbering someone else's state. Would it make sense and scale appropriately for an NT synchronization *object* to be a Linux open file description? Then SCM_RIGHTS could pass them around, an RPC server could manage *named* objects, and they'd generally work just like other "Object Manager" objects like, say, files. --Andy
