Messages in this thread | | | Date | Fri, 4 Jan 2008 12:04:35 +0530 | From | "Abhishek Sagar" <> | Subject | Re: [PATCH] x86: kprobes change kprobe_handler flow |
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On 1/4/08, Masami Hiramatsu <mhiramat@redhat.com> wrote: > I could understand what the original code did at last. > If a kprobe is inserted on a breakpoint which other debugger inserts, > it single step inline instead of out-of-line.(this is done in prepare_singlestep) > In this case, (p && kprobe_running() && kcb->kprobe_status==KPROBE_HIT_SS) > is true and we need pass the control to the debugger. > And if (*p->ainsn.insn != BREAKPOINT_INSTRUCTION) (or (p != kprobe_running())) in > that case, there may be some bugs.
Yes, we can only fault while singlestepping for a unique case, which is when we're singlestepping (in-line) a breakpoint because a probe was installed on it. All other scenarios are a BUG . That's also assuming that no exception will preempt singlestepping, whose codepath has a probe on it.
> Now I think your original suggestion is correct. > Please fix it in another patch.
Ok.
> -- > Masami Hiramatsu > > Software Engineer > Hitachi Computer Products (America) Inc. > Software Solutions Division > > e-mail: mhiramat@redhat.com, masami.hiramatsu.pt@hitachi.com
Thanks, Abhishek Sagar
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