On 12/14/2012 10:44 PM, Andy Lutomirski wrote: > On Fri, Dec 14, 2012 at 10:35 AM, H. Peter Anvin <[email protected]> wrote: >> On 12/14/2012 12:34 AM, Pavel Emelyanov wrote: >>> On 12/14/2012 06:20 AM, Andy Lutomirski wrote: >>>> On Thu, Dec 13, 2012 at 6:18 PM, H. Peter Anvin <[email protected]> wrote: >>>>> Wouldn't the vdso get mapped already and could be mremap()'d. If we >>>> really need more control I'd almost push for a device/filesystem node >>>> that could be mmapped the usual way. >>>> >>>> Hmm. That may work, but it'll still break ABI. I'm not sure that >>>> criu is stable enough yet that we should care. Criu people? >>> >>> It's not yet, but we'd still appreciate the criu-friendly vdso redesign. >>> >>>> (In brief summary: how annoying would it be if the vdso was no longer >>>> just a bunch of constant bytes that lived somewhere?) >>> >>> It depends on what vdso is going to be. In the perfect case it should >>> a) be mremap-able to any address (or be at fixed address _forever_, but >>> I assume this is not feasible); >>> b) have entry points at fixed (or somehow movable) places. >>> >>> I admit that I didn't understand your question properly, if I did, >>> please correct me. >>> >> >> mremap() should work. At the same time, the code itself is not going to >> have any stability guarantees between kernel versions -- it obviously >> cannot. > > We could guarantee that the symbols in the vdso resolve to particular > offsets within the vdso. (Yes, this is ugly.) > > Does criu support checkpointing with one version of a shared library > and restoring with another?
No, neither we have this in plans. However, if somebody needs this and implements -- why not?! Thanks, Pavel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
