Hi, Paul -
[...]
[...] With the various kernel debuggers, kprobes, itrace, and
maybe others trying to share these
[MSR/single-stepping/notify_die] resources do you think it is time
to develop some sort of kernel single stepping API? Frank is
requesting this API before changing SystemTap to support single
step traps.
Actually, I have asked only about user-space single-stepping, possibly
based on the utrace API. Broad kernel-space single-stepping is risky
enough not to attempt yet.
At present kprobes sets the MSR_SE bit in the MSR when it wants to
single-step, and uses the notify_die infrastructure as the way it
gets notified when the single-step trap occurs. [...] In other
words the API for single-stepping is just the notify_die stuff.
[...]
We can attempt this later.
- FChE