(2013/12/05 19:21), Ingo Molnar wrote: > > * Masami Hiramatsu <masami.hiramatsu...@hitachi.com> wrote: > >>> So we need both a maintainable and a sane/safe solution, and I'd >>> like to apply the whole thing at once and be at ease that the >>> solution is round. We should have done this years ago. >> >> For the safeness of kprobes, I have an idea; introduce a whitelist >> for dynamic events. AFAICS, the biggest unstable issue of kprobes >> comes from putting *many* probes on the functions called from >> tracers. > > If the number of 'noprobe' annotations is expected to explode then > maybe another approach should be considered.
No, since this is a "quantitative" issue, the annotation helps us. > For example in perf we detect recursion. Could kprobes do that and > detect hitting a probe while running kprobes code, and ignore it [do > an early return]? Yes, the kprobe itself already has recursion detector and it rejects calling handler. > > That way most of the annotations could be removed and kprobes would > become inherently safe. Is there any complication I'm missing? That is actually what I'm doing with cleanup patches. :) Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
