We ought to move this to generic sys/conf/files

Maybe worth a comment about updating both kdb_frame and the thrctx?

How do you mean? Currently it is no different than other machdep files and should only be included here.

Oh yes, ignore that comment :)

I find some of these hard to follow when they are all on one line.

Does this work in gdb or does it show duplicate stack frames?

Duplicate

Duplicate

I agree, this style is a little odd but is used in other gdb_machdep implementations. I'm not attached to it however.

Do you find it any better if they were aligned like this?

It does work in gdb without duplicates. I believe the reason is that cpu_switch(), where the PC actually is for sleeping threads, doesn't construct a new stack frame.

For stopped threads, the same is true of savectx(), called in ipi_stop().