hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8MGE6 CVE: NA
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There are some codes that can be used in the solution without ftrace, such as module initialization and symbol relocation and so on, so include them into CONFIG_LIVEPATCH.
Also note that CONFIG_LIVEPATCH_WO_FTRACE is still not implemented in this patch.
Signed-off-by: Zheng Yejian zhengyejian1@huawei.com --- include/linux/livepatch.h | 31 +++++++++------ kernel/livepatch/Makefile | 5 ++- kernel/livepatch/core.c | 80 +++++++++++++++++++++++++++++++++++++-- kernel/livepatch/core.h | 4 ++ 4 files changed, 102 insertions(+), 18 deletions(-)
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index 2c6ce24b641a..f635bd6b2c6f 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -72,11 +72,16 @@ struct klp_func { struct list_head node; struct list_head stack_node; unsigned long old_size, new_size; +#ifdef CONFIG_LIVEPATCH_FTRACE bool nop; +#endif bool patched; +#ifdef CONFIG_LIVEPATCH_FTRACE bool transition; +#endif };
+#ifdef CONFIG_LIVEPATCH_FTRACE struct klp_object;
/** @@ -100,6 +105,7 @@ struct klp_callbacks { void (*post_unpatch)(struct klp_object *obj); bool post_unpatch_enabled; }; +#endif /* CONFIG_LIVEPATCH_FTRACE */
/** * struct klp_object - kernel object structure for live patching @@ -118,17 +124,22 @@ struct klp_object { /* external */ const char *name; struct klp_func *funcs; +#ifdef CONFIG_LIVEPATCH_FTRACE struct klp_callbacks callbacks; +#endif
/* internal */ struct kobject kobj; struct list_head func_list; struct list_head node; struct module *mod; +#ifdef CONFIG_LIVEPATCH_FTRACE bool dynamic; +#endif bool patched; };
+#ifdef CONFIG_LIVEPATCH_FTRACE /** * struct klp_state - state of the system modified by the livepatch * @id: system state identifier (non-zero) @@ -140,6 +151,7 @@ struct klp_state { unsigned int version; void *data; }; +#endif /* CONFIG_LIVEPATCH_FTRACE */
/** * struct klp_patch - patch structure for live patching @@ -159,15 +171,19 @@ struct klp_patch { /* external */ struct module *mod; struct klp_object *objs; +#ifdef CONFIG_LIVEPATCH_FTRACE struct klp_state *states; bool replace; +#endif
/* internal */ struct list_head list; struct kobject kobj; struct list_head obj_list; bool enabled; +#ifdef CONFIG_LIVEPATCH_FTRACE bool forced; +#endif struct work_struct free_work; struct completion finish; }; @@ -231,11 +247,6 @@ 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_FTRACE */
static inline int klp_module_coming(struct module *mod) { return 0; } @@ -245,16 +256,12 @@ static inline void klp_update_patch_state(struct task_struct *task) {} static inline void klp_copy_process(struct task_struct *child) {} static inline bool klp_have_reliable_stack(void) { return true; }
-static inline +#endif /* CONFIG_LIVEPATCH_FTRACE */ + 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_FTRACE */ + const char *objname);
#else /* !CONFIG_LIVEPATCH */
diff --git a/kernel/livepatch/Makefile b/kernel/livepatch/Makefile index 18f9cb687576..facf512b237a 100644 --- a/kernel/livepatch/Makefile +++ b/kernel/livepatch/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_LIVEPATCH_FTRACE) += livepatch.o +obj-$(CONFIG_LIVEPATCH) += livepatch.o
-livepatch-objs := core.o patch.o shadow.o state.o transition.o +obj-$(CONFIG_LIVEPATCH_FTRACE) += patch.o shadow.o state.o transition.o +livepatch-objs := core.o diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index ecbc9b6aba3a..28705113b75c 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -22,9 +22,11 @@ #include <linux/rcupdate.h> #include <asm/cacheflush.h> #include "core.h" +#ifdef CONFIG_LIVEPATCH_FTRACE #include "patch.h" #include "state.h" #include "transition.h" +#endif /* CONFIG_LIVEPATCH_FTRACE */
/* * klp_mutex is a coarse lock which serializes access to klp data. All @@ -84,6 +86,7 @@ static bool klp_initialized(void) return !!klp_root_kobj; }
+#ifdef CONFIG_LIVEPATCH_FTRACE static struct klp_func *klp_find_func(struct klp_object *obj, struct klp_func *old_func) { @@ -117,6 +120,7 @@ static struct klp_object *klp_find_object(struct klp_patch *patch,
return NULL; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
struct klp_find_arg { const char *name; @@ -260,6 +264,7 @@ static int klp_resolve_symbols(Elf_Shdr *sechdrs, const char *strtab, return 0; }
+#ifdef CONFIG_LIVEPATCH_FTRACE void __weak clear_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, @@ -267,6 +272,7 @@ void __weak clear_relocate_add(Elf_Shdr *sechdrs, struct module *me) { } +#endif
/* * At a high-level, there are two types of klp relocation sections: those which @@ -325,7 +331,9 @@ static int klp_write_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, return apply_relocate_add(sechdrs, strtab, symndx, secndx, pmod); }
+#ifdef CONFIG_LIVEPATCH_FTRACE clear_relocate_add(sechdrs, strtab, symndx, secndx, pmod); +#endif return 0; }
@@ -350,6 +358,8 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, * /sys/kernel/livepatch/<patch>/<object>/patched * /sys/kernel/livepatch/<patch>/<object>/<function,sympos> */ +#ifdef CONFIG_LIVEPATCH_FTRACE + static int __klp_disable_patch(struct klp_patch *patch);
static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr, @@ -395,6 +405,21 @@ static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr, return count; }
+#else /* !CONFIG_LIVEPATCH_FTRACE */ + +static int __klp_enable_patch(struct klp_patch *patch) +{ + return -EINVAL; +} + +static ssize_t enabled_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + return -EINVAL; +} + +#endif /* CONFIG_LIVEPATCH_FTRACE */ + static ssize_t enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -404,6 +429,7 @@ static ssize_t enabled_show(struct kobject *kobj, return snprintf(buf, PAGE_SIZE-1, "%d\n", patch->enabled); }
+#ifdef CONFIG_LIVEPATCH_FTRACE static ssize_t transition_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -442,18 +468,24 @@ static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
return count; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled); +#ifdef CONFIG_LIVEPATCH_FTRACE static struct kobj_attribute transition_kobj_attr = __ATTR_RO(transition); static struct kobj_attribute force_kobj_attr = __ATTR_WO(force); +#endif /* CONFIG_LIVEPATCH_FTRACE */ static struct attribute *klp_patch_attrs[] = { &enabled_kobj_attr.attr, +#ifdef CONFIG_LIVEPATCH_FTRACE &transition_kobj_attr.attr, &force_kobj_attr.attr, +#endif /* CONFIG_LIVEPATCH_FTRACE */ NULL }; ATTRIBUTE_GROUPS(klp_patch);
+#ifdef CONFIG_LIVEPATCH_FTRACE static ssize_t patched_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -475,12 +507,14 @@ static void klp_free_object_dynamic(struct klp_object *obj) kfree(obj->name); kfree(obj); } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static void klp_init_func_early(struct klp_object *obj, struct klp_func *func); static void klp_init_object_early(struct klp_patch *patch, struct klp_object *obj);
+#ifdef CONFIG_LIVEPATCH_FTRACE static struct klp_object *klp_alloc_object_dynamic(const char *name, struct klp_patch *patch) { @@ -587,6 +621,7 @@ static int klp_add_nops(struct klp_patch *patch)
return 0; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static void klp_kobj_release_patch(struct kobject *kobj) { @@ -604,28 +639,34 @@ static const struct kobj_type klp_ktype_patch = {
static void klp_kobj_release_object(struct kobject *kobj) { +#ifdef CONFIG_LIVEPATCH_FTRACE struct klp_object *obj;
obj = container_of(kobj, struct klp_object, kobj);
if (obj->dynamic) klp_free_object_dynamic(obj); +#endif }
static const struct kobj_type klp_ktype_object = { .release = klp_kobj_release_object, .sysfs_ops = &kobj_sysfs_ops, +#ifdef CONFIG_LIVEPATCH_FTRACE .default_groups = klp_object_groups, +#endif };
static void klp_kobj_release_func(struct kobject *kobj) { +#ifdef CONFIG_LIVEPATCH_FTRACE struct klp_func *func;
func = container_of(kobj, struct klp_func, kobj);
if (func->nop) klp_free_func_nop(func); +#endif }
static const struct kobj_type klp_ktype_func = { @@ -638,14 +679,17 @@ static void __klp_free_funcs(struct klp_object *obj, bool nops_only) struct klp_func *func, *tmp_func;
klp_for_each_func_safe(obj, func, tmp_func) { +#ifdef CONFIG_LIVEPATCH_FTRACE if (nops_only && !func->nop) continue; +#endif
list_del(&func->node); kobject_put(&func->kobj); } }
+#ifdef CONFIG_LIVEPATCH_FTRACE /* Clean up when a patched object is unloaded */ static void klp_free_object_loaded(struct klp_object *obj) { @@ -660,6 +704,7 @@ static void klp_free_object_loaded(struct klp_object *obj) func->new_func = NULL; } } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static void __klp_free_objects(struct klp_patch *patch, bool nops_only) { @@ -667,10 +712,10 @@ static void __klp_free_objects(struct klp_patch *patch, bool nops_only)
klp_for_each_object_safe(patch, obj, tmp_obj) { __klp_free_funcs(obj, nops_only); - +#ifdef CONFIG_LIVEPATCH_FTRACE if (nops_only && !obj->dynamic) continue; - +#endif list_del(&obj->node); kobject_put(&obj->kobj); } @@ -681,10 +726,12 @@ static void klp_free_objects(struct klp_patch *patch) __klp_free_objects(patch, false); }
+#ifdef CONFIG_LIVEPATCH_FTRACE static void klp_free_objects_dynamic(struct klp_patch *patch) { __klp_free_objects(patch, true); } +#endif /* CONFIG_LIVEPATCH_FTRACE */
/* * This function implements the free operations that can be called safely @@ -720,9 +767,13 @@ static void klp_free_patch_finish(struct klp_patch *patch) kobject_put(&patch->kobj); wait_for_completion(&patch->finish);
+#ifdef CONFIG_LIVEPATCH_FTRACE /* Put the module after the last access to struct klp_patch. */ if (!patch->forced) module_put(patch->mod); +#else + module_put(patch->mod); +#endif /* CONFIG_LIVEPATCH_FTRACE */ }
/* @@ -738,6 +789,7 @@ static void klp_free_patch_work_fn(struct work_struct *work) klp_free_patch_finish(patch); }
+#ifdef CONFIG_LIVEPATCH_FTRACE void klp_free_patch_async(struct klp_patch *patch) { klp_free_patch_start(patch); @@ -754,25 +806,33 @@ void klp_free_replaced_patches_async(struct klp_patch *new_patch) klp_free_patch_async(old_patch); } } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static int klp_init_func(struct klp_object *obj, struct klp_func *func) { if (!func->old_name) return -EINVAL;
+#ifdef CONFIG_LIVEPATCH_FTRACE /* * NOPs get the address later. The patched module must be loaded, * see klp_init_object_loaded(). */ if (!func->new_func && !func->nop) return -EINVAL; +#else /* !CONFIG_LIVEPATCH_FTRACE */ + if (!func->new_func) + return -EINVAL; +#endif /* CONFIG_LIVEPATCH_FTRACE */
if (strlen(func->old_name) >= KSYM_NAME_LEN) return -EINVAL;
INIT_LIST_HEAD(&func->stack_node); func->patched = false; +#ifdef CONFIG_LIVEPATCH_FTRACE func->transition = false; +#endif
/* The format for the sysfs directory is <function,sympos> where sympos * is the nth occurrence of this symbol in kallsyms for the patched @@ -814,11 +874,13 @@ static int klp_apply_object_relocs(struct klp_patch *patch, return klp_write_object_relocs(patch, obj, true); }
+#ifdef CONFIG_LIVEPATCH_FTRACE static void klp_clear_object_relocs(struct klp_patch *patch, struct klp_object *obj) { klp_write_object_relocs(patch, obj, false); } +#endif /* CONFIG_LIVEPATCH_FTRACE */
/* parts of the initialization that is done only when the object is loaded */ static int klp_init_object_loaded(struct klp_patch *patch, @@ -853,10 +915,10 @@ static int klp_init_object_loaded(struct klp_patch *patch, func->old_name); return -ENOENT; } - +#ifdef CONFIG_LIVEPATCH_FTRACE if (func->nop) func->new_func = func->old_func; - +#endif ret = kallsyms_lookup_size_offset((unsigned long)func->new_func, &func->new_size, NULL); if (!ret) { @@ -924,7 +986,9 @@ static void klp_init_patch_early(struct klp_patch *patch) INIT_LIST_HEAD(&patch->obj_list); kobject_init(&patch->kobj, &klp_ktype_patch); patch->enabled = false; +#ifdef CONFIG_LIVEPATCH_FTRACE patch->forced = false; +#endif INIT_WORK(&patch->free_work, klp_free_patch_work_fn); init_completion(&patch->finish);
@@ -946,11 +1010,13 @@ static int klp_init_patch(struct klp_patch *patch) if (ret) return ret;
+#ifdef CONFIG_LIVEPATCH_FTRACE if (patch->replace) { ret = klp_add_nops(patch); if (ret) return ret; } +#endif
klp_for_each_object(patch, obj) { ret = klp_init_object(patch, obj); @@ -963,6 +1029,7 @@ static int klp_init_patch(struct klp_patch *patch) return 0; }
+#ifdef CONFIG_LIVEPATCH_FTRACE static int __klp_disable_patch(struct klp_patch *patch) { struct klp_object *obj; @@ -1049,6 +1116,7 @@ static int __klp_enable_patch(struct klp_patch *patch) klp_cancel_transition(); return ret; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
/** * klp_enable_patch() - enable the livepatch @@ -1093,12 +1161,14 @@ int klp_enable_patch(struct klp_patch *patch)
mutex_lock(&klp_mutex);
+#ifdef CONFIG_LIVEPATCH_FTRACE if (!klp_is_patch_compatible(patch)) { pr_err("Livepatch patch (%s) is not compatible with the already installed livepatches.\n", patch->mod->name); mutex_unlock(&klp_mutex); return -EINVAL; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
if (!try_module_get(patch->mod)) { mutex_unlock(&klp_mutex); @@ -1130,6 +1200,7 @@ int klp_enable_patch(struct klp_patch *patch) } EXPORT_SYMBOL_GPL(klp_enable_patch);
+#ifdef CONFIG_LIVEPATCH_FTRACE /* * This function unpatches objects from the replaced livepatches. * @@ -1313,6 +1384,7 @@ void klp_module_going(struct module *mod)
mutex_unlock(&klp_mutex); } +#endif /* CONFIG_LIVEPATCH_FTRACE */
static int __init klp_init(void) { diff --git a/kernel/livepatch/core.h b/kernel/livepatch/core.h index 38209c7361b6..20f916239125 100644 --- a/kernel/livepatch/core.h +++ b/kernel/livepatch/core.h @@ -13,16 +13,19 @@ extern struct list_head klp_patches; #define klp_for_each_patch(patch) \ list_for_each_entry(patch, &klp_patches, list)
+#ifdef CONFIG_LIVEPATCH_FTRACE void klp_free_patch_async(struct klp_patch *patch); void klp_free_replaced_patches_async(struct klp_patch *new_patch); void klp_unpatch_replaced_patches(struct klp_patch *new_patch); void klp_discard_nops(struct klp_patch *new_patch); +#endif /* CONFIG_LIVEPATCH_FTRACE */
static inline bool klp_is_object_loaded(struct klp_object *obj) { return !obj->name || obj->mod; }
+#ifdef CONFIG_LIVEPATCH_FTRACE static inline int klp_pre_patch_callback(struct klp_object *obj) { int ret = 0; @@ -55,5 +58,6 @@ static inline void klp_post_unpatch_callback(struct klp_object *obj)
obj->callbacks.post_unpatch_enabled = false; } +#endif /* CONFIG_LIVEPATCH_FTRACE */
#endif /* _LIVEPATCH_CORE_H */