On Tue, Jul 18, 2017 at 01:15:16PM +0200, Miroslav Benes wrote: > On Thu, 13 Jul 2017, Josh Poimboeuf wrote: > > > On Wed, Jul 12, 2017 at 10:10:00AM -0400, Joe Lawrence wrote: > > > When the livepatch core executes klp_(un)patch_object, call out to a > > > livepatch-module specified array of callback hooks. These hooks provide > > > a notification mechanism for livepatch modules when klp_objects are > > > (un)patching. This may be most interesting when another kernel module > > > is a klp_object target and the livepatch module needs to execute code > > > after the target is loaded, but before its module_init code is run. > > > > And it's also useful for vmlinux. Patch module load/unload is separate > > from enable/disable, so the module init/exit functions can't be used for > > patch-specific changes (e.g., global data changes). > > I admit that I don't understand this, which is probably the reason for my > question. Why do we need it when we have module notifiers and module > init/exit functions in the kernel? Petr described different possible > scenarios and they can be solved either in init/exit function of a patch > module or in a module notifier which the patch module can register. > > If there is a difference, it should be mentioned in the documentation and > in the changelog. Some differences: - The patch module init/exit code doesn't run when disabling and re-enabling a patch. - The module notifier can't stop the to-be-patched module from loading. -- Josh -- 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
