On Tue, 6 Feb 2018, Petr Mladek wrote: > From: Jason Baron <jbaron@xxxxxxxxxx> > > We are going to add a feature called atomic replace. It will allow to > create a patch that would replace all already registered patches. > For this, we will need to dynamically create funcs and objects > for functions that are not longer patched. > > This patch adds basic framework to handle such dynamic structures. > > It adds enum klp_func_type that allows to distinguish the dynamically > allocated funcs' structures. Note that objects' structures do not have > a clear type. Namely the static objects' structures might list both static > and dynamic funcs' structures. > > The function type is then used to limit klp_free() functions. We will > want to free the dynamic structures separately when they are not > longer needed. At the same time, we also want to make our life easier, > and introduce _any_ type that will allow to process all existing > structures in one go. > > We need to be careful here. First, objects' structures must be freed > only when all listed funcs' structures are freed. Also we must avoid > double free. Both problems are solved by removing the freed structures > from the list. > > Also note that klp_free*() functions are called also in klp_init_patch() > error path when only some kobjects have been initialized. The other > dynamic structures must be freed immediately by calling the respective > klp_free_*_dynamic() functions. > > Finally, the dynamic objects' structures are generic. The respective > klp_allocate_object_dynamic() and klp_free_object_dynamic() can > be implemented here. On the other hand, klp_free_func_dynamic() > is empty. It must be updated when a particular dynamic > klp_func_type is introduced. > > Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx> > [pmladek@xxxxxxxx: Converted into a generic API] > Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> > Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > Cc: Jessica Yu <jeyu@xxxxxxxxxx> > Cc: Jiri Kosina <jikos@xxxxxxxxxx> > Cc: Miroslav Benes <mbenes@xxxxxxx> This patch introduces klp_get_or_add_object(), but it is not used here. One of the later patches adds its call site. GCC warns about this. I like it being introduced here, because it belongs to the patch. Someone may complain though. Also klp_free_objects() is not declared as static and sparse complains about it. Petr, you can make it static here and drop the keyword later. Otherwise it looks good. Acked-by: Miroslav Benes <mbenes@xxxxxxx> 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
