On Tue, Nov 21, 2017 at 10:05:08PM +0000, Mathieu Desnoyers wrote: > Other than that, I have not received any concrete alternative proposal to > properly handle single-stepping. That's not entirely true; amluto did have an alternative in Prague: do full machine level instruction emulation till the end of the rseq when it gets 'preempted too often'. Yes, implementing that will be an absolute royal pain. But it does remove the whole duplicate/dual program asm/bytecode thing and avoids the syscall entirely. And we don't need to do a full x86_64/arch-of-choice emulator for this either; just as cpu_opv is fairly limited too. We can do a subset that allows dealing with the known sequences and go from there -- it can always fall back to not emulating and reverting to the pure rseq with debug/fwd progress 'issues'. So what exactly is the problem of leaving out the whole cpu_opv thing for now? Pure rseq is usable -- albeit a bit cumbersome without additional debugger support. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
