diff options
Diffstat (limited to 'include/linux/livepatch.h')
| -rw-r--r-- | include/linux/livepatch.h | 68 |
1 files changed, 56 insertions, 12 deletions
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index 9072f04db616..194991ef9347 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -23,15 +23,16 @@ #include <linux/module.h> #include <linux/ftrace.h> +#include <linux/completion.h> #if IS_ENABLED(CONFIG_LIVEPATCH) #include <asm/livepatch.h> -enum klp_state { - KLP_DISABLED, - KLP_ENABLED -}; +/* task patch states */ +#define KLP_UNDEFINED -1 +#define KLP_UNPATCHED 0 +#define KLP_PATCHED 1 /** * struct klp_func - function structure for live patching @@ -39,10 +40,29 @@ enum klp_state { * @new_func: pointer to the patched function code * @old_sympos: a hint indicating which symbol position the old function * can be found (optional) + * @immediate: patch the func immediately, bypassing safety mechanisms * @old_addr: the address of the function being patched * @kobj: kobject for sysfs resources - * @state: tracks function-level patch application state * @stack_node: list node for klp_ops func_stack list + * @old_size: size of the old function + * @new_size: size of the new function + * @patched: the func has been added to the klp_ops list + * @transition: the func is currently being applied or reverted + * + * The patched and transition variables define the func's patching state. When + * patching, a func is always in one of the following states: + * + * patched=0 transition=0: unpatched + * patched=0 transition=1: unpatched, temporary starting state + * patched=1 transition=1: patched, may be visible to some tasks + * patched=1 transition=0: patched, visible to all tasks + * + * And when unpatching, it goes in the reverse order: + * + * patched=1 transition=0: patched, visible to all tasks + * patched=1 transition=1: patched, may be visible to some tasks + * patched=0 transition=1: unpatched, temporary ending state + * patched=0 transition=0: unpatched */ struct klp_func { /* external */ @@ -56,12 +76,15 @@ struct klp_func { * in kallsyms for the given object is used. */ unsigned long old_sympos; + bool immediate; /* internal */ unsigned long old_addr; struct kobject kobj; - enum klp_state state; struct list_head stack_node; + unsigned long old_size, new_size; + bool patched; + bool transition; }; /** @@ -70,8 +93,8 @@ struct klp_func { * @funcs: function entries for functions to be patched in the object * @kobj: kobject for sysfs resources * @mod: kernel module associated with the patched object - * (NULL for vmlinux) - * @state: tracks object-level patch application state + * (NULL for vmlinux) + * @patched: the object's funcs have been added to the klp_ops list */ struct klp_object { /* external */ @@ -81,26 +104,30 @@ struct klp_object { /* internal */ struct kobject kobj; struct module *mod; - enum klp_state state; + bool patched; }; /** * struct klp_patch - patch structure for live patching * @mod: reference to the live patch module * @objs: object entries for kernel objects to be patched + * @immediate: patch all funcs immediately, bypassing safety mechanisms * @list: list node for global list of registered patches * @kobj: kobject for sysfs resources - * @state: tracks patch-level application state + * @enabled: the patch is enabled (but operation may be incomplete) + * @finish: for waiting till it is safe to remove the patch module */ struct klp_patch { /* external */ struct module *mod; struct klp_object *objs; + bool immediate; /* internal */ struct list_head list; struct kobject kobj; - enum klp_state state; + bool enabled; + struct completion finish; }; #define klp_for_each_object(patch, obj) \ @@ -123,10 +150,27 @@ void arch_klp_init_object_loaded(struct klp_patch *patch, int klp_module_coming(struct module *mod); void klp_module_going(struct module *mod); +void klp_copy_process(struct task_struct *child); +void klp_update_patch_state(struct task_struct *task); + +static inline bool klp_patch_pending(struct task_struct *task) +{ + return test_tsk_thread_flag(task, TIF_PATCH_PENDING); +} + +static inline bool klp_have_reliable_stack(void) +{ + return IS_ENABLED(CONFIG_STACKTRACE) && + IS_ENABLED(CONFIG_HAVE_RELIABLE_STACKTRACE); +} + #else /* !CONFIG_LIVEPATCH */ static inline int klp_module_coming(struct module *mod) { return 0; } -static inline void klp_module_going(struct module *mod) { } +static inline void klp_module_going(struct module *mod) {} +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) {} #endif /* CONFIG_LIVEPATCH */ |