On Fri, Oct 3, 2014 at 1:44 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > On Fri, Oct 03, 2014 at 01:27:52PM -0700, Andy Lutomirski wrote: >> On Fri, Oct 3, 2014 at 1:22 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: >> > >> > We could make the rule be that RDPMC is enabled if a perf event is >> > mmapped or TIF_SECCOMP is clear, but I'd prefer to be convinced that >> > there's an actual performance issue first. Ideally we can get this >> > all working with no API or ABI change at all. >> >> No, we can't use that rule. But we could say that RDPMC is enabled if >> a perf event is mmapped and no thread in the mm uses seccomp. I'll >> grumble a little bit about adding yet another piece of seccomp state. > > Well, we could simply disable the RDPMC for everything TIF_SECCOMP. > Should be fairly straight fwd. That won't work. I bet there are plenty of existing users of fairly wide-open seccomp sandboxes that allow perf_event in. -- Andy Lutomirski AMA Capital Management, LLC -- 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
