Re: [PATCH v7 4/7] livepatch: Allow to unpatch only functions of the given type

From: Miroslav Benes
Date: Fri Feb 09 2018 - 07:29:55 EST



> +/*
> + * Remove ftrace handler for the given object and function type.

Isn't it imprecise? It does not necessarily remove ftrace handler. It
removes a function of given ftype from func_stack. I'd remove the
sentence.

> + *
> + * It keeps obj->patched flag true when any listed function is still patched.
> + * The caller is responsible for removing the unpatched functions to
> + * make the flag clean again.
> + */
> +void klp_unpatch_object(struct klp_object *obj, enum klp_func_type ftype)
> {
> struct klp_func *func;
> + bool patched = false;
>
> - klp_for_each_func(obj, func)
> - if (func->patched)
> + klp_for_each_func(obj, func) {
> + if (!func->patched)
> + continue;
> +
> + if (klp_is_func_type(func, ftype))
> klp_unpatch_func(func);
> + else
> + patched = true;
> + }
>
> - obj->patched = false;
> + obj->patched = patched;
> }
>
> int klp_patch_object(struct klp_object *obj)
> @@ -258,7 +272,7 @@ int klp_patch_object(struct klp_object *obj)
> klp_for_each_func(obj, func) {
> ret = klp_patch_func(func);
> if (ret) {
> - klp_unpatch_object(obj);
> + klp_unpatch_object(obj, KLP_FUNC_ANY);
> return ret;
> }
> }
> @@ -267,11 +281,12 @@ int klp_patch_object(struct klp_object *obj)
> return 0;
> }
>
> -void klp_unpatch_objects(struct klp_patch *patch)
> +/* Removes ftrace handler in all objects for the given function type. */

Same here.

> +void klp_unpatch_objects(struct klp_patch *patch, enum klp_func_type ftype)
> {
> struct klp_object *obj;
>
> klp_for_each_object(patch, obj)
> if (obj->patched)
> - klp_unpatch_object(obj);
> + klp_unpatch_object(obj, ftype);
> }

Miroslav