Re: Why do kprobes and uprobes singlestep?

[Oleg Nesterov]

On 03/02, Masami Hiramatsu wrote:
>
> > Not sure I understand you correctly, I know almost nothing about low-level
> > x86  magic.
>
> x86 has normal interrupt and NMI. When an NMI occurs the CPU masks NMI
> (the mask itself is hidden status) and IRET releases the mask. The problem
> is that if an INT3 is hit in the NMI handler and does a single-stepping,
> it has to use IRET for atomically setting TF and return.

Ah, thanks a lot,

Oleg.