(2013/12/13 14:34), Masami Hiramatsu wrote: >> Lets assume we allow a probe to be inserted in the single-step path. >> Such a probe will be an INT3 instruction and if it hits we get a >> recursive INT3 invocation. In that case the INT3 handler should simply >> restore the original instruction and _leave it so_. There's no >> single-stepping needed - the probe is confused and must be discarded. > > But how can we restore the protected kernel text? > If we use text_poke, we also need to prohibit probing on the text_poke > and functions called in the text_poke too. That just shifts the annotated > area to the text_poke. :(
BTW, currently we mark the text_poke as nokprobe_symbol, but it should be removed. We don't call it from kprobes int3/debug handlers. The patches which removes __kprobes in this series are only for kprobe related files (arch/x86/kernel/kprobes/* or kernel/kprobes.c.) I think we should do it for other parts. Is it better to do that on this series? 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/
