163 строки
3.8 KiB
C
163 строки
3.8 KiB
C
// 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");
|