// SPDX-License-Identifier: GPL-2.0/* * Init code for a livepatch kernel module */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h>#include <linux/slab.h>#include <linux/livepatch.h> static struct klp_patch *patch; static int __init livepatch_mod_init(void){	struct klp_object_ext *obj_exts;	size_t obj_exts_sec_size;	struct klp_object *objs;	unsigned int nr_objs;	int ret; 	obj_exts = klp_find_section_by_name(THIS_MODULE, ".init.klp_objects",					    &obj_exts_sec_size);	nr_objs = obj_exts_sec_size / sizeof(*obj_exts);	if (!nr_objs) {		pr_err("nothing to patch!\n");		ret = -EINVAL;		goto err;	} 	patch = kzalloc(sizeof(*patch), GFP_KERNEL);	if (!patch) {		ret = -ENOMEM;		goto err;	} 	objs = kzalloc(sizeof(struct klp_object) * (nr_objs + 1),  GFP_KERNEL);	if (!objs) {		ret = -ENOMEM;		goto err_free_patch;	} 	for (int i = 0; i < nr_objs; i++) {		struct klp_object_ext *obj_ext = obj_exts + i;		struct klp_func_ext *funcs_ext = obj_ext->funcs;		unsigned int nr_funcs = obj_ext->nr_funcs;		struct klp_func *funcs = objs[i].funcs;		struct klp_object *obj = objs + i; 		funcs = kzalloc(sizeof(struct klp_func) * (nr_funcs + 1), GFP_KERNEL);		if (!funcs) {			ret = -ENOMEM;			for (int j = 0; j < i; j++)				kfree(objs[i].funcs);			goto err_free_objs;		} 		for (int j = 0; j < nr_funcs; j++) {			funcs[j].old_name   = funcs_ext[j].old_name;			funcs[j].new_func   = funcs_ext[j].new_func;			funcs[j].old_sympos = funcs_ext[j].sympos;		} 		obj->name = obj_ext->name;		obj->funcs = funcs; 		memcpy(&obj->callbacks, &obj_ext->callbacks, sizeof(struct klp_callbacks));	} 	patch->mod = THIS_MODULE;	patch->objs = objs; 	/* TODO patch->states */ #ifdef KLP_NO_REPLACE	patch->replace = false;#else	patch->replace = true;#endif 	return klp_enable_patch(patch); err_free_objs:	kfree(objs);err_free_patch:	kfree(patch);err:	return ret;} static void __exit livepatch_mod_exit(void){	struct klp_object *obj; 	klp_for_each_object_static(patch, obj)		kfree(obj->funcs); 	kfree(patch->objs);	kfree(patch);} module_init(livepatch_mod_init);module_exit(livepatch_mod_exit);MODULE_LICENSE("GPL");MODULE_INFO(livepatch, "Y");MODULE_DESCRIPTION("Livepatch module");