RE: [PATCH v5 22/34] x86/fred: FRED initialization code

[Li, Xin3]

> > The purpose of separate stacks for NMI, #DB and #MC *in the kernel*
> > (remember that user space faults are always taken on stack level 0) is
> > to avoid overflowing the kernel stack. #DB in the kernel would imply
> > the use of a kernel debugger.
> 
> Perf (and through it bpf) also has access to #DB. They can set
> breakpoints on kernel instructions/memory just fine provided permission
> etc.

So they are still *kernel* debuggers :)