livepatch: Don't block the removal of patches loaded after a forced transition
module_put() is currently never called in klp_complete_transition() when
klp_force is set. As a result, we might keep the reference count even when
klp_enable_patch() fails and klp_cancel_transition() is called.
This might give the impression that a module might get blocked in some
strange init state. Fortunately, it is not the case. The reference count
is ignored when mod->init fails and erroneous modules are always removed.
Anyway, this might be confusing. Instead, this patch moves
the global klp_forced flag into struct klp_patch. As a result,
we block only modules that might still be in use after a forced
transition. Newly loaded livepatches might be eventually completely
removed later.
It is not a big deal. But the code is at least consistent with
the reality.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 6f0d909..e77c501 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -45,7 +45,8 @@
*/
DEFINE_MUTEX(klp_mutex);
-static LIST_HEAD(klp_patches);
+/* Registered patches */
+LIST_HEAD(klp_patches);
static struct kobject *klp_root_kobj;
@@ -659,6 +660,7 @@
INIT_LIST_HEAD(&patch->list);
patch->kobj_added = false;
patch->enabled = false;
+ patch->forced = false;
init_completion(&patch->finish);
klp_for_each_object(patch, obj) {