Currently klp_patch contains a pointer to a statically allocated array of struct klp_object and struct klp_objects contains a pointer to a statically allocated array of klp_func. In order to allow for the dynamic allocation of objects and functions, link klp_patch, klp_object, and klp_func together via linked lists. This allows us to more easily allocate new objects and functions, while having the iterator be a simple linked list walk.
This patch is intended to be a no-op until atomic replace is introduced by a subsequent patch. Signed-off-by: Jason Baron <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Jessica Yu <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Miroslav Benes <[email protected]> Cc: Petr Mladek <[email protected]> --- include/linux/livepatch.h | 19 +++++++++++++++++-- kernel/livepatch/core.c | 8 ++++++-- 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index 194991e..482f90b 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -24,6 +24,7 @@ #include <linux/module.h> #include <linux/ftrace.h> #include <linux/completion.h> +#include <linux/list.h> #if IS_ENABLED(CONFIG_LIVEPATCH) @@ -44,6 +45,7 @@ * @old_addr: the address of the function being patched * @kobj: kobject for sysfs resources * @stack_node: list node for klp_ops func_stack list + * @func_entry: links struct klp_func to struct klp_object * @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 @@ -82,6 +84,7 @@ struct klp_func { unsigned long old_addr; struct kobject kobj; struct list_head stack_node; + struct list_head func_entry; unsigned long old_size, new_size; bool patched; bool transition; @@ -94,6 +97,8 @@ struct klp_func { * @kobj: kobject for sysfs resources * @mod: kernel module associated with the patched object * (NULL for vmlinux) + * @func_list: head of list for struct klp_func + * @obj_entry: links struct klp_object to struct klp_patch * @patched: the object's funcs have been added to the klp_ops list */ struct klp_object { @@ -103,6 +108,8 @@ struct klp_object { /* internal */ struct kobject kobj; + struct list_head func_list; + struct list_head obj_entry; struct module *mod; bool patched; }; @@ -114,6 +121,7 @@ struct klp_object { * @immediate: patch all funcs immediately, bypassing safety mechanisms * @list: list node for global list of registered patches * @kobj: kobject for sysfs resources + * @obj_list: head of list for struct klp_object * @enabled: the patch is enabled (but operation may be incomplete) * @finish: for waiting till it is safe to remove the patch module */ @@ -126,18 +134,25 @@ struct klp_patch { /* internal */ struct list_head list; struct kobject kobj; + struct list_head obj_list; bool enabled; 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(patch, obj) \ + list_for_each_entry(obj, &patch->obj_list, obj_entry) + +#define klp_for_each_func_static(obj, func) \ for (func = obj->funcs; \ func->old_name || func->new_func || func->old_sympos; \ func++) +#define klp_for_each_func(obj, func) \ + list_for_each_entry(func, &obj->func_list, func_entry) + int klp_register_patch(struct klp_patch *); int klp_unregister_patch(struct klp_patch *); int klp_enable_patch(struct klp_patch *); diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index b9628e4..b7f77be 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -608,6 +608,7 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func) INIT_LIST_HEAD(&func->stack_node); func->patched = false; func->transition = false; + list_add(&func->func_entry, &obj->func_list); /* The format for the sysfs directory is <function,sympos> where sympos * is the nth occurrence of this symbol in kallsyms for the patched @@ -689,7 +690,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj) if (ret) return ret; - klp_for_each_func(obj, func) { + list_add(&obj->obj_entry, &patch->obj_list); + INIT_LIST_HEAD(&obj->func_list); + klp_for_each_func_static(obj, func) { ret = klp_init_func(obj, func); if (ret) goto free; @@ -729,7 +732,8 @@ static int klp_init_patch(struct klp_patch *patch) return ret; } - klp_for_each_object(patch, obj) { + INIT_LIST_HEAD(&patch->obj_list); + klp_for_each_object_static(patch, obj) { ret = klp_init_object(patch, obj); if (ret) goto free; -- 2.6.1
