On Tue, 15 Oct 2019, Joe Lawrence wrote: > On 10/15/19 10:13 AM, Miroslav Benes wrote: > > Yes, it does. klp_module_coming() calls module_disable_ro() on all > > patching modules which patch the coming module in order to call > > apply_relocate_add(). New (patching) code for a module can be relocated > > only when the relevant module is loaded. > > FWIW, would the LPC blue-sky2 model (ie, Steve's suggestion @ plumber's where > livepatches only patch a single object and updates are kept on disk to handle > coming module updates as they are loaded) eliminate those outstanding > relocations and the need to perform this late permission flipping? Yes, it should, but we don't have to wait for it. PeterZ proposed a different solution to this specific issue in https://lore.kernel.org/lkml/20191015141111.GP2359@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ It should not be a problem to create a live patch module like that and the code in kernel/livepatch/ is almost ready. Something like module_section_disable_ro(mod, section) (and similar for X protection) should be enough. Module reloads would still require juggling with the protections, but I think it is all feasible. Miroslav
