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-rw-r--r--kernel/include/linux/livepatch.h133
1 files changed, 133 insertions, 0 deletions
diff --git a/kernel/include/linux/livepatch.h b/kernel/include/linux/livepatch.h
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+++ b/kernel/include/linux/livepatch.h
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+/*
+ * 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_
+#define _LINUX_LIVEPATCH_H_
+
+#include <linux/module.h>
+#include <linux/ftrace.h>
+
+#if IS_ENABLED(CONFIG_LIVEPATCH)
+
+#include <asm/livepatch.h>
+
+enum klp_state {
+ KLP_DISABLED,
+ KLP_ENABLED
+};
+
+/**
+ * struct klp_func - function structure for live patching
+ * @old_name: name of the function to be patched
+ * @new_func: pointer to the patched function code
+ * @old_addr: a hint conveying at what address the old function
+ * can be found (optional, vmlinux patches only)
+ * @kobj: kobject for sysfs resources
+ * @state: tracks function-level patch application state
+ * @stack_node: list node for klp_ops func_stack list
+ */
+struct klp_func {
+ /* external */
+ const char *old_name;
+ void *new_func;
+ /*
+ * The old_addr field is optional and can be used to resolve
+ * duplicate symbol names in the vmlinux object. If this
+ * information is not present, the symbol is located by name
+ * with kallsyms. If the name is not unique and old_addr is
+ * not provided, the patch application fails as there is no
+ * way to resolve the ambiguity.
+ */
+ unsigned long old_addr;
+
+ /* internal */
+ struct kobject kobj;
+ enum klp_state state;
+ struct list_head stack_node;
+};
+
+/**
+ * struct klp_reloc - relocation structure for live patching
+ * @loc: address where the relocation will be written
+ * @val: address of the referenced symbol (optional,
+ * vmlinux patches only)
+ * @type: ELF relocation type
+ * @name: name of the referenced symbol (for lookup/verification)
+ * @addend: offset from the referenced symbol
+ * @external: symbol is either exported or within the live patch module itself
+ */
+struct klp_reloc {
+ unsigned long loc;
+ unsigned long val;
+ unsigned long type;
+ const char *name;
+ int addend;
+ int external;
+};
+
+/**
+ * struct klp_object - kernel object structure for live patching
+ * @name: module name (or NULL for vmlinux)
+ * @relocs: relocation entries to be applied at load time
+ * @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
+ */
+struct klp_object {
+ /* external */
+ const char *name;
+ struct klp_reloc *relocs;
+ struct klp_func *funcs;
+
+ /* internal */
+ struct kobject *kobj;
+ struct module *mod;
+ enum klp_state state;
+};
+
+/**
+ * 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
+ * @kobj: kobject for sysfs resources
+ * @state: tracks patch-level application state
+ */
+struct klp_patch {
+ /* external */
+ struct module *mod;
+ struct klp_object *objs;
+
+ /* internal */
+ struct list_head list;
+ struct kobject kobj;
+ enum klp_state state;
+};
+
+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 *);
+
+#endif /* CONFIG_LIVEPATCH */
+
+#endif /* _LINUX_LIVEPATCH_H_ */