[PATCH -tip v8 02/26] kprobes/x86: Allow to handle reentered kprobe on singlestepping

[Steven Rostedt]

On Wed, 05 Mar 2014 20:58:57 +0900
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> Since the NMI handlers(e.g. perf) can interrupt in the
> single stepping (or preparing the single stepping, do_debug
> etc.), we should consider a kprobe is hit in the NMI
> handler. Even in that case, the kprobe is allowed to be
> reentered as same as the kprobes hit in kprobe handlers
> (KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE).
> The real issue will happen when a kprobe hit while another
> reentered kprobe is processing (KPROBE_REENTER), because
> we already consumed a saved-area for the previous kprobe.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>

Reviewed-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve