On Fri, 13 Feb 2015, Josh Poimboeuf wrote: > On Fri, Feb 13, 2015 at 01:57:38PM +0100, Miroslav Benes wrote: > > On Mon, 9 Feb 2015, Josh Poimboeuf wrote: > > > > > Once we have a consistency model, patches and their objects will be > > > enabled and disabled at different times. For example, when a patch is > > > disabled, its loaded objects' funcs can remain registered with ftrace > > > indefinitely until the unpatching operation is complete and they're no > > > longer in use. > > > > > > It's less confusing if we give them different names: patches can be > > > enabled or disabled; objects (and their funcs) can be patched or > > > unpatched: > > > > > > - Enabled means that a patch is logically enabled (but not necessarily > > > fully applied). > > > > > > - Patched means that an object's funcs are registered with ftrace and > > > added to the klp_ops func stack. > > > > > > Also, since these states are binary, represent them with boolean-type > > > variables instead of enums. > > > > They are binary now but will it hold also in the future? I cannot come up > > with any other possible state of the function right now, but that doesn't > > mean there isn't any. It would be sad to return it back to enums one day > > :) > > I really can't think of any reason why they would become non-binary. > IMO it's more likely we could add more boolean variables, but if that > got out of hand we could just switch to using bit flags. > > Either way I don't see a problem with changing them later if we need to. Agreed. > > Also would it be useful to expose patched variable for functions and > > objects in sysfs? > > Not that I know of. Do you have a use case in mind? I view "patched" > as an internal variable, corresponding to whether the object or its > functions are registered with ftrace/klp_ops. It doesn't mean "patched" > in a way that would really make sense to the user, because of the > gradual nature of the patching process. The only reasonable thing which I thought about was in case of an error. If something bad happens it could be useful to know which state the functions are in (patched/unpatched). Anyway it is nothing of importance right now and we can add it anytime later if we decide it useful. Miroslav -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
