diff options
Diffstat (limited to 'include/linux/livepatch.h')
| -rw-r--r-- | include/linux/livepatch.h | 126 |
1 files changed, 73 insertions, 53 deletions
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index aec44b1d9582..772919e8096a 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -1,21 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * livepatch.h - Kernel Live Patching Core * * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com> * Copyright (C) 2014 SUSE - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #ifndef _LINUX_LIVEPATCH_H_ @@ -24,15 +12,16 @@ #include <linux/module.h> #include <linux/ftrace.h> #include <linux/completion.h> +#include <linux/list.h> +#include <linux/livepatch_external.h> +#include <linux/livepatch_sched.h> #if IS_ENABLED(CONFIG_LIVEPATCH) -#include <asm/livepatch.h> - /* task patch states */ -#define KLP_UNDEFINED -1 -#define KLP_UNPATCHED 0 -#define KLP_PATCHED 1 +#define KLP_TRANSITION_IDLE -1 +#define KLP_TRANSITION_UNPATCHED 0 +#define KLP_TRANSITION_PATCHED 1 /** * struct klp_func - function structure for live patching @@ -40,11 +29,13 @@ * @new_func: pointer to the patched function code * @old_sympos: a hint indicating which symbol position the old function * can be found (optional) - * @old_addr: the address of the function being patched + * @old_func: pointer to the function being patched * @kobj: kobject for sysfs resources + * @node: list node for klp_object func_list * @stack_node: list node for klp_ops func_stack list * @old_size: size of the old function * @new_size: size of the new function + * @nop: temporary patch to use the original code again; dyn. allocated * @patched: the func has been added to the klp_ops list * @transition: the func is currently being applied or reverted * @@ -77,46 +68,27 @@ struct klp_func { unsigned long old_sympos; /* internal */ - unsigned long old_addr; + void *old_func; struct kobject kobj; + struct list_head node; struct list_head stack_node; unsigned long old_size, new_size; + bool nop; bool patched; bool transition; }; -struct klp_object; - -/** - * struct klp_callbacks - pre/post live-(un)patch callback structure - * @pre_patch: executed before code patching - * @post_patch: executed after code patching - * @pre_unpatch: executed before code unpatching - * @post_unpatch: executed after code unpatching - * @post_unpatch_enabled: flag indicating if post-unpatch callback - * should run - * - * All callbacks are optional. Only the pre-patch callback, if provided, - * will be unconditionally executed. If the parent klp_object fails to - * patch for any reason, including a non-zero error status returned from - * the pre-patch callback, no further callbacks will be executed. - */ -struct klp_callbacks { - int (*pre_patch)(struct klp_object *obj); - void (*post_patch)(struct klp_object *obj); - void (*pre_unpatch)(struct klp_object *obj); - void (*post_unpatch)(struct klp_object *obj); - bool post_unpatch_enabled; -}; - /** * struct klp_object - kernel object structure for live patching * @name: module name (or NULL for vmlinux) * @funcs: function entries for functions to be patched in the object * @callbacks: functions to be executed pre/post (un)patching * @kobj: kobject for sysfs resources + * @func_list: dynamic list of the function entries + * @node: list node for klp_patch obj_list * @mod: kernel module associated with the patched object * (NULL for vmlinux) + * @dynamic: temporary object for nop functions; dynamically allocated * @patched: the object's funcs have been added to the klp_ops list */ struct klp_object { @@ -127,46 +99,77 @@ struct klp_object { /* internal */ struct kobject kobj; + struct list_head func_list; + struct list_head node; struct module *mod; + bool dynamic; bool patched; }; /** + * struct klp_state - state of the system modified by the livepatch + * @id: system state identifier (non-zero) + * @version: version of the change + * @data: custom data + */ +struct klp_state { + unsigned long id; + unsigned int version; + void *data; +}; + +/** * struct klp_patch - patch structure for live patching * @mod: reference to the live patch module * @objs: object entries for kernel objects to be patched - * @list: list node for global list of registered patches + * @states: system states that can get modified + * @replace: replace all actively used patches + * @list: list node for global list of actively used patches * @kobj: kobject for sysfs resources + * @obj_list: dynamic list of the object entries * @enabled: the patch is enabled (but operation may be incomplete) + * @forced: was involved in a forced transition + * @free_work: patch cleanup from workqueue-context * @finish: for waiting till it is safe to remove the patch module */ struct klp_patch { /* external */ struct module *mod; struct klp_object *objs; + struct klp_state *states; + bool replace; /* internal */ struct list_head list; struct kobject kobj; + struct list_head obj_list; bool enabled; + bool forced; + struct work_struct free_work; struct completion finish; }; -#define klp_for_each_object(patch, obj) \ +#define klp_for_each_object_static(patch, obj) \ for (obj = patch->objs; obj->funcs || obj->name; obj++) -#define klp_for_each_func(obj, func) \ +#define klp_for_each_object_safe(patch, obj, tmp_obj) \ + list_for_each_entry_safe(obj, tmp_obj, &patch->obj_list, node) + +#define klp_for_each_object(patch, obj) \ + list_for_each_entry(obj, &patch->obj_list, node) + +#define klp_for_each_func_static(obj, func) \ for (func = obj->funcs; \ func->old_name || func->new_func || func->old_sympos; \ func++) -int klp_register_patch(struct klp_patch *); -int klp_unregister_patch(struct klp_patch *); -int klp_enable_patch(struct klp_patch *); -int klp_disable_patch(struct klp_patch *); +#define klp_for_each_func_safe(obj, func, tmp_func) \ + list_for_each_entry_safe(func, tmp_func, &obj->func_list, node) + +#define klp_for_each_func(obj, func) \ + list_for_each_entry(func, &obj->func_list, node) -void arch_klp_init_object_loaded(struct klp_patch *patch, - struct klp_object *obj); +int klp_enable_patch(struct klp_patch *); /* Called from the module loader during module coming/going states */ int klp_module_coming(struct module *mod); @@ -201,6 +204,14 @@ void *klp_shadow_get_or_alloc(void *obj, unsigned long id, void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor); void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor); +struct klp_state *klp_get_state(struct klp_patch *patch, unsigned long id); +struct klp_state *klp_get_prev_state(unsigned long id); + +int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, + const char *shstrtab, const char *strtab, + unsigned int symindex, unsigned int secindex, + const char *objname); + #else /* !CONFIG_LIVEPATCH */ static inline int klp_module_coming(struct module *mod) { return 0; } @@ -209,6 +220,15 @@ static inline bool klp_patch_pending(struct task_struct *task) { return false; } static inline void klp_update_patch_state(struct task_struct *task) {} static inline void klp_copy_process(struct task_struct *child) {} +static inline +int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, + const char *shstrtab, const char *strtab, + unsigned int symindex, unsigned int secindex, + const char *objname) +{ + return 0; +} + #endif /* CONFIG_LIVEPATCH */ #endif /* _LINUX_LIVEPATCH_H_ */ |