On Thu, 1 Feb 2018, Josh Poimboeuf wrote: > On Thu, Feb 01, 2018 at 04:08:14PM +0100, Miroslav Benes wrote: > > On Thu, 1 Feb 2018, Joe Lawrence wrote: > > > > > On 02/01/2018 08:49 AM, Miroslav Benes wrote: > > > > > > > > Well, one more thing. I think there is a problem with shadow variables. > > > > Similar to callbacks situation. Shadow variables cannot be destroyed > > > > the > > > > way it is shown in our samples. Cumulative patches want to preserve > > > > everything as much as possible. If I'm right, it should be mentioned in > > > > the documentation. > > > > > > Are you talking about using klp_shadow_free_all() call in a module_exit > > > routine? Yeah, I think in this case, that responsibility would be > > > passed to the newly loaded cumulative patch, right? > > > > Yes, but we haven't got an option not to call it here (as with callbacks, > > where we can omit callbacks completely with atomic replace patches). A > > live patch author must be aware of this and use shadow variables > > appropriately. > > So maybe we should recommend that shadow variables generally be freed > from a post-unpatch callback.
Yes, that's a possibility. In other words, if there is a need to call klp_shadow_free_all() somewhere, it should be in a post-unpatch callback. Miroslav
