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1// SPDX-License-Identifier: GPL-2.02// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>3 4#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt5 6#include <linux/module.h>7#include <linux/kernel.h>8#include <linux/livepatch.h>9 10static int pre_patch_ret;11module_param(pre_patch_ret, int, 0644);12MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)");13 14static const char *const module_state[] = {15 [MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",16 [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",17 [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",18 [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",19};20 21static void callback_info(const char *callback, struct klp_object *obj)22{23 if (obj->mod)24 pr_info("%s: %s -> %s\n", callback, obj->mod->name,25 module_state[obj->mod->state]);26 else27 pr_info("%s: vmlinux\n", callback);28}29 30/* Executed on object patching (ie, patch enablement) */31static int pre_patch_callback(struct klp_object *obj)32{33 callback_info(__func__, obj);34 return pre_patch_ret;35}36 37/* Executed on object unpatching (ie, patch disablement) */38static void post_patch_callback(struct klp_object *obj)39{40 callback_info(__func__, obj);41}42 43/* Executed on object unpatching (ie, patch disablement) */44static void pre_unpatch_callback(struct klp_object *obj)45{46 callback_info(__func__, obj);47}48 49/* Executed on object unpatching (ie, patch disablement) */50static void post_unpatch_callback(struct klp_object *obj)51{52 callback_info(__func__, obj);53}54 55static void patched_work_func(struct work_struct *work)56{57 pr_info("%s\n", __func__);58}59 60static struct klp_func no_funcs[] = {61 {}62};63 64static struct klp_func busymod_funcs[] = {65 {66 .old_name = "busymod_work_func",67 .new_func = patched_work_func,68 }, {}69};70 71static struct klp_object objs[] = {72 {73 .name = NULL, /* vmlinux */74 .funcs = no_funcs,75 .callbacks = {76 .pre_patch = pre_patch_callback,77 .post_patch = post_patch_callback,78 .pre_unpatch = pre_unpatch_callback,79 .post_unpatch = post_unpatch_callback,80 },81 }, {82 .name = "test_klp_callbacks_mod",83 .funcs = no_funcs,84 .callbacks = {85 .pre_patch = pre_patch_callback,86 .post_patch = post_patch_callback,87 .pre_unpatch = pre_unpatch_callback,88 .post_unpatch = post_unpatch_callback,89 },90 }, {91 .name = "test_klp_callbacks_busy",92 .funcs = busymod_funcs,93 .callbacks = {94 .pre_patch = pre_patch_callback,95 .post_patch = post_patch_callback,96 .pre_unpatch = pre_unpatch_callback,97 .post_unpatch = post_unpatch_callback,98 },99 }, { }100};101 102static struct klp_patch patch = {103 .mod = THIS_MODULE,104 .objs = objs,105};106 107static int test_klp_callbacks_demo_init(void)108{109 return klp_enable_patch(&patch);110}111 112static void test_klp_callbacks_demo_exit(void)113{114}115 116module_init(test_klp_callbacks_demo_init);117module_exit(test_klp_callbacks_demo_exit);118MODULE_LICENSE("GPL");119MODULE_INFO(livepatch, "Y");120MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");121MODULE_DESCRIPTION("Livepatch test: livepatch demo");122