OSDev.org

Hi,

Could userspace still being considered userspace if it doesn't mess with the kernel virtual space but use DPL 0 permission (it can alter interrupt states and so on)?

Granted, that can be dangerous and let all sorts of bad things happen.

But, is it still considered userspace?

Bye

Hi,

AlexHully wrote:Could userspace still being considered userspace if it doesn't mess with the kernel virtual space but use DPL 0 permission (it can alter interrupt states and so on)?

Yes; it could still be considered user space (but couldn't be considered secure, unless the OS is doing something else to ensure isolation - e.g. managed code).

Don't forget that you could set IOPL=3 to allow CPL=3 tasks to use some things (HLT, CLI/STI, IO ports) without given them full access to things like CR0, CR3, MSRs, etc.


Cheers,

Brendan

Perfect.

Thanks a lot Brendan