test_klp_atomic_replace.c (1308B)
1// SPDX-License-Identifier: GPL-2.0 2// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com> 3 4#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 5 6#include <linux/module.h> 7#include <linux/kernel.h> 8#include <linux/livepatch.h> 9 10static int replace; 11module_param(replace, int, 0644); 12MODULE_PARM_DESC(replace, "replace (default=0)"); 13 14#include <linux/seq_file.h> 15static int livepatch_meminfo_proc_show(struct seq_file *m, void *v) 16{ 17 seq_printf(m, "%s: %s\n", THIS_MODULE->name, 18 "this has been live patched"); 19 return 0; 20} 21 22static struct klp_func funcs[] = { 23 { 24 .old_name = "meminfo_proc_show", 25 .new_func = livepatch_meminfo_proc_show, 26 }, {} 27}; 28 29static struct klp_object objs[] = { 30 { 31 /* name being NULL means vmlinux */ 32 .funcs = funcs, 33 }, {} 34}; 35 36static struct klp_patch patch = { 37 .mod = THIS_MODULE, 38 .objs = objs, 39 /* set .replace in the init function below for demo purposes */ 40}; 41 42static int test_klp_atomic_replace_init(void) 43{ 44 patch.replace = replace; 45 return klp_enable_patch(&patch); 46} 47 48static void test_klp_atomic_replace_exit(void) 49{ 50} 51 52module_init(test_klp_atomic_replace_init); 53module_exit(test_klp_atomic_replace_exit); 54MODULE_LICENSE("GPL"); 55MODULE_INFO(livepatch, "Y"); 56MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>"); 57MODULE_DESCRIPTION("Livepatch test: atomic replace");