1 files changed, 133 insertions, 0 deletions

diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h
new file mode 100644
index 000000000000..95023fd8b00d
--- /dev/null
+++ b/include/linux/livepatch.h
@@ -0,0 +1,133 @@
+/*
+ * 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;
+};
+
+extern int klp_register_patch(struct klp_patch *);
+extern int klp_unregister_patch(struct klp_patch *);
+extern int klp_enable_patch(struct klp_patch *);
+extern int klp_disable_patch(struct klp_patch *);
+
+#endif /* CONFIG_LIVEPATCH */
+
+#endif /* _LINUX_LIVEPATCH_H_ */