acrn-kernel/lib/livepatch/test_klp_callbacks_demo2.c

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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>
static int replace;
module_param(replace, int, 0644);
MODULE_PARM_DESC(replace, "replace (default=0)");
static const char *const module_state[] = {
[MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
[MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
[MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
[MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
};
static void callback_info(const char *callback, struct klp_object *obj)
{
if (obj->mod)
pr_info("%s: %s -> %s\n", callback, obj->mod->name,
module_state[obj->mod->state]);
else
pr_info("%s: vmlinux\n", callback);
}
/* Executed on object patching (ie, patch enablement) */
static int pre_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
return 0;
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_patch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void pre_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
/* Executed on object unpatching (ie, patch disablement) */
static void post_unpatch_callback(struct klp_object *obj)
{
callback_info(__func__, obj);
}
static struct klp_func no_funcs[] = {
{ }
};
static struct klp_object objs[] = {
{
.name = NULL, /* vmlinux */
.funcs = no_funcs,
.callbacks = {
.pre_patch = pre_patch_callback,
.post_patch = post_patch_callback,
.pre_unpatch = pre_unpatch_callback,
.post_unpatch = post_unpatch_callback,
},
}, { }
};
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
/* set .replace in the init function below for demo purposes */
};
static int test_klp_callbacks_demo2_init(void)
{
patch.replace = replace;
return klp_enable_patch(&patch);
}
static void test_klp_callbacks_demo2_exit(void)
{
}
module_init(test_klp_callbacks_demo2_init);
module_exit(test_klp_callbacks_demo2_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
MODULE_DESCRIPTION("Livepatch test: livepatch demo2");