Merge tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching updates from Petr Mladek:

 - Correctly handle kobjects when a livepatch init fails

 - Avoid CPU hogging when searching for many livepatched symbols

 - Add livepatch API page into documentation

* tag 'livepatching-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  livepatch: Avoid CPU hogging with cond_resched
  livepatch: Fix missing unlock on error in klp_enable_patch()
  livepatch: Fix kobject refcount bug on klp_init_patch_early failure path
  Documentation: livepatch: Add livepatch API page

1 files changed, 13 insertions, 16 deletions

diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 335d988bd811..585494ec464f 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -862,14 +862,11 @@ static void klp_init_object_early(struct klp_patch *patch,
 	list_add_tail(&obj->node, &patch->obj_list);
 }
 
-static int klp_init_patch_early(struct klp_patch *patch)
+static void klp_init_patch_early(struct klp_patch *patch)
 {
 	struct klp_object *obj;
 	struct klp_func *func;
 
-	if (!patch->objs)
-		return -EINVAL;
-
 	INIT_LIST_HEAD(&patch->list);
 	INIT_LIST_HEAD(&patch->obj_list);
 	kobject_init(&patch->kobj, &klp_ktype_patch);
@@ -879,20 +876,12 @@ static int klp_init_patch_early(struct klp_patch *patch)
 	init_completion(&patch->finish);
 
 	klp_for_each_object_static(patch, obj) {
-		if (!obj->funcs)
-			return -EINVAL;
-
 		klp_init_object_early(patch, obj);
 
 		klp_for_each_func_static(obj, func) {
 			klp_init_func_early(obj, func);
 		}
 	}
-
-	if (!try_module_get(patch->mod))
-		return -ENODEV;
-
-	return 0;
 }
 
 static int klp_init_patch(struct klp_patch *patch)
@@ -1024,10 +1013,17 @@ err:
 int klp_enable_patch(struct klp_patch *patch)
 {
 	int ret;
+	struct klp_object *obj;
 
-	if (!patch || !patch->mod)
+	if (!patch || !patch->mod || !patch->objs)
 		return -EINVAL;
 
+	klp_for_each_object_static(patch, obj) {
+		if (!obj->funcs)
+			return -EINVAL;
+	}
+
+
 	if (!is_livepatch_module(patch->mod)) {
 		pr_err("module %s is not marked as a livepatch module\n",
 		       patch->mod->name);
@@ -1051,12 +1047,13 @@ int klp_enable_patch(struct klp_patch *patch)
 		return -EINVAL;
 	}
 
-	ret = klp_init_patch_early(patch);
-	if (ret) {
+	if (!try_module_get(patch->mod)) {
 		mutex_unlock(&klp_mutex);
-		return ret;
+		return -ENODEV;
 	}
 
+	klp_init_patch_early(patch);
+
 	ret = klp_init_patch(patch);
 	if (ret)
 		goto err;