25 #include "patch.h"
71 	 * Note that the patch might still be needed before klp_module_going()  in klp_find_object_module()
102 static struct klp_object *klp_find_object(struct klp_patch *patch,  in klp_find_object()  argument
107 	klp_for_each_object(patch, obj) {  in klp_find_object()
345  * /sys/kernel/livepatch/<patch>
346  * /sys/kernel/livepatch/<patch>/enabled
347  * /sys/kernel/livepatch/<patch>/transition
348  * /sys/kernel/livepatch/<patch>/force
349  * /sys/kernel/livepatch/<patch>/replace
350  * /sys/kernel/livepatch/<patch>/stack_order
351  * /sys/kernel/livepatch/<patch>/<object>
352  * /sys/kernel/livepatch/<patch>/<object>/patched
353  * /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
355 static int __klp_disable_patch(struct klp_patch *patch);
360 	struct klp_patch *patch;  in enabled_store()  local
368 	patch = container_of(kobj, struct klp_patch, kobj);  in enabled_store()
372 	if (patch->enabled == enabled) {  in enabled_store()
383 	 * Do not allow to re-enable a disabled patch.  in enabled_store()
385 	if (patch == klp_transition_patch)  in enabled_store()
388 		ret = __klp_disable_patch(patch);  in enabled_store()
403 	struct klp_patch *patch;  in enabled_show()  local
405 	patch = container_of(kobj, struct klp_patch, kobj);  in enabled_show()
406 	return sysfs_emit(buf, "%d\n", patch->enabled);  in enabled_show()
412 	struct klp_patch *patch;  in transition_show()  local
414 	patch = container_of(kobj, struct klp_patch, kobj);  in transition_show()
415 	return sysfs_emit(buf, "%d\n", patch == klp_transition_patch);  in transition_show()
421 	struct klp_patch *patch;  in force_store()  local
434 	patch = container_of(kobj, struct klp_patch, kobj);  in force_store()
435 	if (patch != klp_transition_patch) {  in force_store()
450 	struct klp_patch *patch;  in replace_show()  local
452 	patch = container_of(kobj, struct klp_patch, kobj);  in replace_show()
453 	return sysfs_emit(buf, "%d\n", patch->replace);  in replace_show()
459 	struct klp_patch *patch, *this_patch;  in stack_order_show()  local
466 	klp_for_each_patch(patch) {  in stack_order_show()
468 		if (patch == this_patch)  in stack_order_show()
516 static void klp_init_object_early(struct klp_patch *patch,
520 						   struct klp_patch *patch)  in klp_alloc_object_dynamic()  argument
536 	klp_init_object_early(patch, obj);  in klp_alloc_object_dynamic()
576 static int klp_add_object_nops(struct klp_patch *patch,  in klp_add_object_nops()  argument
582 	obj = klp_find_object(patch, old_obj);  in klp_add_object_nops()
585 		obj = klp_alloc_object_dynamic(old_obj->name, patch);  in klp_add_object_nops()
606  * patch to facilitate a 'replace' mode.
608 static int klp_add_nops(struct klp_patch *patch)  in klp_add_nops()  argument
617 			err = klp_add_object_nops(patch, old_obj);  in klp_add_nops()
628 	struct klp_patch *patch;  in klp_kobj_release_patch()  local
630 	patch = container_of(kobj, struct klp_patch, kobj);  in klp_kobj_release_patch()
631 	complete(&patch->finish);  in klp_kobj_release_patch()
699 static void __klp_free_objects(struct klp_patch *patch, bool nops_only)  in __klp_free_objects()  argument
703 	klp_for_each_object_safe(patch, obj, tmp_obj) {  in __klp_free_objects()
714 static void klp_free_objects(struct klp_patch *patch)  in klp_free_objects()  argument
716 	__klp_free_objects(patch, false);  in klp_free_objects()
719 static void klp_free_objects_dynamic(struct klp_patch *patch)  in klp_free_objects_dynamic()  argument
721 	__klp_free_objects(patch, true);  in klp_free_objects_dynamic()
731 static void klp_free_patch_start(struct klp_patch *patch)  in klp_free_patch_start()  argument
733 	if (!list_empty(&patch->list))  in klp_free_patch_start()
734 		list_del(&patch->list);  in klp_free_patch_start()
736 	klp_free_objects(patch);  in klp_free_patch_start()
744  * the last function accessing the livepatch structures when the patch
747 static void klp_free_patch_finish(struct klp_patch *patch)  in klp_free_patch_finish()  argument
752 	 * this is called when the patch gets disabled and it  in klp_free_patch_finish()
755 	kobject_put(&patch->kobj);  in klp_free_patch_finish()
756 	wait_for_completion(&patch->finish);  in klp_free_patch_finish()
759 	if (!patch->forced)  in klp_free_patch_finish()
760 		module_put(patch->mod);  in klp_free_patch_finish()
764  * The livepatch might be freed from sysfs interface created by the patch.
770 	struct klp_patch *patch =  in klp_free_patch_work_fn()  local
773 	klp_free_patch_finish(patch);  in klp_free_patch_work_fn()
776 void klp_free_patch_async(struct klp_patch *patch)  in klp_free_patch_async()  argument
778 	klp_free_patch_start(patch);  in klp_free_patch_async()
779 	schedule_work(&patch->free_work);  in klp_free_patch_async()
822 static int klp_write_object_relocs(struct klp_patch *patch,  in klp_write_object_relocs()  argument
827 	struct klp_modinfo *info = patch->mod->klp_info;  in klp_write_object_relocs()
835 		ret = klp_write_section_relocs(patch->mod, info->sechdrs,  in klp_write_object_relocs()
837 					       patch->mod->core_kallsyms.strtab,  in klp_write_object_relocs()
846 static int klp_apply_object_relocs(struct klp_patch *patch,  in klp_apply_object_relocs()  argument
849 	return klp_write_object_relocs(patch, obj, true);  in klp_apply_object_relocs()
852 static void klp_clear_object_relocs(struct klp_patch *patch,  in klp_clear_object_relocs()  argument
855 	klp_write_object_relocs(patch, obj, false);  in klp_clear_object_relocs()
859 static int klp_init_object_loaded(struct klp_patch *patch,  in klp_init_object_loaded()  argument
872 		ret = klp_apply_object_relocs(patch, obj);  in klp_init_object_loaded()
907 static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)  in klp_init_object()  argument
922 	ret = kobject_add(&obj->kobj, &patch->kobj, "%s", name);  in klp_init_object()
933 		ret = klp_init_object_loaded(patch, obj);  in klp_init_object()
945 static void klp_init_object_early(struct klp_patch *patch,  in klp_init_object_early()  argument
950 	list_add_tail(&obj->node, &patch->obj_list);  in klp_init_object_early()
953 static void klp_init_patch_early(struct klp_patch *patch)  in klp_init_patch_early()  argument
958 	INIT_LIST_HEAD(&patch->list);  in klp_init_patch_early()
959 	INIT_LIST_HEAD(&patch->obj_list);  in klp_init_patch_early()
960 	kobject_init(&patch->kobj, &klp_ktype_patch);  in klp_init_patch_early()
961 	patch->enabled = false;  in klp_init_patch_early()
962 	patch->forced = false;  in klp_init_patch_early()
963 	INIT_WORK(&patch->free_work, klp_free_patch_work_fn);  in klp_init_patch_early()
964 	init_completion(&patch->finish);  in klp_init_patch_early()
966 	klp_for_each_object_static(patch, obj) {  in klp_init_patch_early()
967 		klp_init_object_early(patch, obj);  in klp_init_patch_early()
975 static int klp_init_patch(struct klp_patch *patch)  in klp_init_patch()  argument
980 	ret = kobject_add(&patch->kobj, klp_root_kobj, "%s", patch->mod->name);  in klp_init_patch()
984 	if (patch->replace) {  in klp_init_patch()
985 		ret = klp_add_nops(patch);  in klp_init_patch()
990 	klp_for_each_object(patch, obj) {  in klp_init_patch()
991 		ret = klp_init_object(patch, obj);  in klp_init_patch()
996 	list_add_tail(&patch->list, &klp_patches);  in klp_init_patch()
1001 static int __klp_disable_patch(struct klp_patch *patch)  in __klp_disable_patch()  argument
1005 	if (WARN_ON(!patch->enabled))  in __klp_disable_patch()
1011 	klp_init_transition(patch, KLP_TRANSITION_UNPATCHED);  in __klp_disable_patch()
1013 	klp_for_each_object(patch, obj)  in __klp_disable_patch()
1027 	patch->enabled = false;  in __klp_disable_patch()
1033 static int __klp_enable_patch(struct klp_patch *patch)  in __klp_enable_patch()  argument
1041 	if (WARN_ON(patch->enabled))  in __klp_enable_patch()
1044 	pr_notice("enabling patch '%s'\n", patch->mod->name);  in __klp_enable_patch()
1046 	klp_init_transition(patch, KLP_TRANSITION_PATCHED);  in __klp_enable_patch()
1057 	klp_for_each_object(patch, obj) {  in __klp_enable_patch()
1063 			pr_warn("pre-patch callback failed for object '%s'\n",  in __klp_enable_patch()
1070 			pr_warn("failed to patch object '%s'\n",  in __klp_enable_patch()
1077 	patch->enabled = true;  in __klp_enable_patch()
1082 	pr_warn("failed to enable patch '%s'\n", patch->mod->name);  in __klp_enable_patch()
1090  * @patch:	patch to be enabled
1092  * Initializes the data structure associated with the patch, creates the sysfs
1101 int klp_enable_patch(struct klp_patch *patch)  in klp_enable_patch()  argument
1106 	if (!patch || !patch->mod || !patch->objs)  in klp_enable_patch()
1109 	klp_for_each_object_static(patch, obj) {  in klp_enable_patch()
1115 	if (!is_livepatch_module(patch->mod)) {  in klp_enable_patch()
1117 		       patch->mod->name);  in klp_enable_patch()
1131 	if (!klp_is_patch_compatible(patch)) {  in klp_enable_patch()
1132 		pr_err("Livepatch patch (%s) is not compatible with the already installed livepatches.\n",  in klp_enable_patch()
1133 			patch->mod->name);  in klp_enable_patch()
1138 	if (!try_module_get(patch->mod)) {  in klp_enable_patch()
1143 	klp_init_patch_early(patch);  in klp_enable_patch()
1145 	ret = klp_init_patch(patch);  in klp_enable_patch()
1149 	ret = __klp_enable_patch(patch);  in klp_enable_patch()
1158 	klp_free_patch_start(patch);  in klp_enable_patch()
1162 	klp_free_patch_finish(patch);  in klp_enable_patch()
1178  * klp_ftrace_handler() might still see the replaced patch on the stack.
1181  * this is handled transparently by patch->module_put.
1226 	struct klp_patch *patch;  in klp_cleanup_module_patches_limited()  local
1229 	klp_for_each_patch(patch) {  in klp_cleanup_module_patches_limited()
1230 		if (patch == limit)  in klp_cleanup_module_patches_limited()
1233 		klp_for_each_object(patch, obj) {  in klp_cleanup_module_patches_limited()
1237 			if (patch != klp_transition_patch)  in klp_cleanup_module_patches_limited()
1240 			pr_notice("reverting patch '%s' on unloading module '%s'\n",  in klp_cleanup_module_patches_limited()
1241 				  patch->mod->name, obj->mod->name);  in klp_cleanup_module_patches_limited()
1245 			klp_clear_object_relocs(patch, obj);  in klp_cleanup_module_patches_limited()
1255 	struct klp_patch *patch;  in klp_module_coming()  local
1270 	 * get patched by a new patch.  in klp_module_coming()
1274 	klp_for_each_patch(patch) {  in klp_module_coming()
1275 		klp_for_each_object(patch, obj) {  in klp_module_coming()
1281 			ret = klp_init_object_loaded(patch, obj);  in klp_module_coming()
1283 				pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",  in klp_module_coming()
1284 					patch->mod->name, obj->mod->name, ret);  in klp_module_coming()
1288 			pr_notice("applying patch '%s' to loading module '%s'\n",  in klp_module_coming()
1289 				  patch->mod->name, obj->mod->name);  in klp_module_coming()
1293 				pr_warn("pre-patch callback failed for object '%s'\n",  in klp_module_coming()
1300 				pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",  in klp_module_coming()
1301 					patch->mod->name, obj->mod->name, ret);  in klp_module_coming()
1307 			if (patch != klp_transition_patch)  in klp_module_coming()
1320 	 * If a patch is unsuccessfully applied, return  in klp_module_coming()
1323 	pr_warn("patch '%s' failed for module '%s', refusing to load module '%s'\n",  in klp_module_coming()
1324 		patch->mod->name, obj->mod->name, obj->mod->name);  in klp_module_coming()
1327 	klp_cleanup_module_patches_limited(mod, patch);  in klp_module_coming()
1343 	 * get patched by a new patch.  in klp_module_going()