can windbg k command show call stack of user mode when debugging kernel mode

each time i am debugging kernel mode, and i have chance to use k command to check call stack as well as !process to check current process.

suppose i am debugging WDDM, and i place a breakpoint on this function, DxgkddiBuildpagingbuffer, when the breakpoint is hit, then i use !process to check current process is LogonUI.exe, but windbg k command shows

dxgmms2!VidMmWorkerThreadProc+0x9
nt!PspSystemThreadStartup+0x55
nt!KiStartSystemThread+0x2a

the call stack is from nt!KiStartSystemThread

Is LogonUI.exe part of system process?

Is LogonUI.exe part of system process?

No, but kernel system threads can run in the context of any process.

Thanks @Tim_Roberts