Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 SUSE
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/printk.h>
#include <linux/livepatch.h>
 
#define CONSOLE_LOGLEVEL_STATE 1
/* Version 1 does not support migration. */
#define CONSOLE_LOGLEVEL_STATE_VERSION 1
 
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);
}
 
static struct klp_patch patch;
 
static int allocate_loglevel_state(void)
{
<------>struct klp_state *loglevel_state;
 
<------>loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
<------>if (!loglevel_state)
<------><------>return -EINVAL;
 
<------>loglevel_state->data = kzalloc(sizeof(console_loglevel), GFP_KERNEL);
<------>if (!loglevel_state->data)
<------><------>return -ENOMEM;
 
<------>pr_info("%s: allocating space to store console_loglevel\n",
<------><------>__func__);
<------>return 0;
}
 
static void fix_console_loglevel(void)
{
<------>struct klp_state *loglevel_state;
 
<------>loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
<------>if (!loglevel_state)
<------><------>return;
 
<------>pr_info("%s: fixing console_loglevel\n", __func__);
<------>*(int *)loglevel_state->data = console_loglevel;
<------>console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
}
 
static void restore_console_loglevel(void)
{
<------>struct klp_state *loglevel_state;
 
<------>loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
<------>if (!loglevel_state)
<------><------>return;
 
<------>pr_info("%s: restoring console_loglevel\n", __func__);
<------>console_loglevel = *(int *)loglevel_state->data;
}
 
static void free_loglevel_state(void)
{
<------>struct klp_state *loglevel_state;
 
<------>loglevel_state = klp_get_state(&patch, CONSOLE_LOGLEVEL_STATE);
<------>if (!loglevel_state)
<------><------>return;
 
<------>pr_info("%s: freeing space for the stored console_loglevel\n",
<------><------>__func__);
<------>kfree(loglevel_state->data);
}
 
/* Executed on object patching (ie, patch enablement) */
static int pre_patch_callback(struct klp_object *obj)
{
<------>callback_info(__func__, obj);
<------>return allocate_loglevel_state();
}
 
/* Executed on object unpatching (ie, patch disablement) */
static void post_patch_callback(struct klp_object *obj)
{
<------>callback_info(__func__, obj);
<------>fix_console_loglevel();
}
 
/* Executed on object unpatching (ie, patch disablement) */
static void pre_unpatch_callback(struct klp_object *obj)
{
<------>callback_info(__func__, obj);
<------>restore_console_loglevel();
}
 
/* Executed on object unpatching (ie, patch disablement) */
static void post_unpatch_callback(struct klp_object *obj)
{
<------>callback_info(__func__, obj);
<------>free_loglevel_state();
}
 
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_state states[] = {
<------>{
<------><------>.id = CONSOLE_LOGLEVEL_STATE,
<------><------>.version = CONSOLE_LOGLEVEL_STATE_VERSION,
<------>}, { }
};
 
static struct klp_patch patch = {
<------>.mod = THIS_MODULE,
<------>.objs = objs,
<------>.states = states,
<------>.replace = true,
};
 
static int test_klp_callbacks_demo_init(void)
{
<------>return klp_enable_patch(&patch);
}
 
static void test_klp_callbacks_demo_exit(void)
{
}
 
module_init(test_klp_callbacks_demo_init);
module_exit(test_klp_callbacks_demo_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
MODULE_AUTHOR("Petr Mladek <pmladek@suse.com>");
MODULE_DESCRIPTION("Livepatch test: system state modification");