In Windows it’s also good. The way it works is follows.
The OS support multiple desktops. Similar to files or registry keys, desktops have security descriptors attached (a data structure keeping who’s the owner, and optionally listing users/groups with their respective permissions on the object being controlled).
To do anything on a desktop, like create windows, paint stuff, or interact with windows on that desktop, user doing that is required to pass an access check against the security descriptor of the desktop. If failed, these GUI-related functions gonna return “access denied” status code instead of doing anything.
The login screen is simply rendered on a separate desktop. That desktop has restrictive security descriptor, most users don’t have permissions to interact with them. UAC prompts are also displayed on another desktop, that’s how it’s impossible to automate them from within a program who triggered the UAC prompt.
BTW, about crashing GPU drivers, on modern Windows the condition is recoverable. The symptoms are black screen for a second, then the OS resets the hardware, restarts the driver, and resumes rendering of the desktop. Observed quite a few times working on advanced GPU stuff, especially compute shaders.
> BTW, about crashing GPU drivers, on modern Windows the condition is recoverable. The symptoms are black screen for a second, then the OS resets the hardware, restarts the driver, and resumes rendering of the desktop. Observed quite a few times working on advanced GPU stuff, especially compute shaders.
When I mine cryptocurrency while playing games, I appear to sometimes run out of GPU memory (Both Task Manager and MSI Afterburner let me monitor usage) and I have experienced this reset. It's surprisingly graceful, even when a game is running, though NVIDIA Broadcast often doesn't like it and needs to be restarted, and I will sometimes see lingering graphical glitches in the game until I restart, but it's not game breaking.
You can also trigger a GPU reset manually with CTRL-WIN-SHIFT-B.
The OS support multiple desktops. Similar to files or registry keys, desktops have security descriptors attached (a data structure keeping who’s the owner, and optionally listing users/groups with their respective permissions on the object being controlled).
To do anything on a desktop, like create windows, paint stuff, or interact with windows on that desktop, user doing that is required to pass an access check against the security descriptor of the desktop. If failed, these GUI-related functions gonna return “access denied” status code instead of doing anything.
The login screen is simply rendered on a separate desktop. That desktop has restrictive security descriptor, most users don’t have permissions to interact with them. UAC prompts are also displayed on another desktop, that’s how it’s impossible to automate them from within a program who triggered the UAC prompt.
BTW, about crashing GPU drivers, on modern Windows the condition is recoverable. The symptoms are black screen for a second, then the OS resets the hardware, restarts the driver, and resumes rendering of the desktop. Observed quite a few times working on advanced GPU stuff, especially compute shaders.