On Wed, 9 Jan 2019, Petr Mladek wrote: > The code for freeing livepatch structures is a bit scattered and tricky: > > + direct calls to klp_free_*_limited() and kobject_put() are > used to release partially initialized objects > > + klp_free_patch() removes the patch from the public list > and releases all objects except for patch->kobj > > + object_put(&patch->kobj) and the related wait_for_completion() > are called directly outside klp_mutex; this code is duplicated; > > Now, we are going to remove the registration stage to simplify the API > and the code. This would require handling more situations in > klp_enable_patch() error paths. > > More importantly, we are going to add a feature called atomic replace. > It will need to dynamically create func and object structures. We will > want to reuse the existing init() and free() functions. This would > create even more error path scenarios. > > This patch implements more straightforward free functions: > > + checks kobj_added flag instead of @limit[*] > > + initializes patch->list early so that the check for empty list > always works > > + The action(s) that has to be done outside klp_mutex are done > in separate klp_free_patch_finish() function. It waits only > when patch->kobj was really released via the _start() part. > > The patch does not change the existing behavior. > > [*] We need our own flag to track that the kobject was successfully > added to the hierarchy. Note that kobj.state_initialized only > indicates that kobject has been initialized, not whether is has > been added (and needs to be removed on cleanup). > > Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> > Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > Cc: Miroslav Benes <mbenes@xxxxxxx> > Cc: Jessica Yu <jeyu@xxxxxxxxxx> > Cc: Jiri Kosina <jikos@xxxxxxxxxx> > Cc: Jason Baron <jbaron@xxxxxxxxxx> Acked-by: Miroslav Benes <mbenes@xxxxxxx> Miroslav
