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 10 static int replace; 11 module_param(replace, int, 0644); 12 MODULE_PARM_DESC(replace, "replace (default=0)"); 13 14 #include <linux/seq_file.h> livepatch_meminfo_proc_show(struct seq_file * m,void * v)15 static 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 22 static struct klp_func funcs[] = { 23 { 24 .old_name = "meminfo_proc_show", 25 .new_func = livepatch_meminfo_proc_show, 26 }, {} 27 }; 28 29 static struct klp_object objs[] = { 30 { 31 /* name being NULL means vmlinux */ 32 .funcs = funcs, 33 }, {} 34 }; 35 36 static struct klp_patch patch = { 37 .mod = THIS_MODULE, 38 .objs = objs, 39 /* set .replace in the init function below for demo purposes */ 40 }; 41 test_klp_atomic_replace_init(void)42 static int test_klp_atomic_replace_init(void) 43 { 44 patch.replace = replace; 45 return klp_enable_patch(&patch); 46 } 47 test_klp_atomic_replace_exit(void)48 static void test_klp_atomic_replace_exit(void) 49 { 50 } 51 52 module_init(test_klp_atomic_replace_init); 53 module_exit(test_klp_atomic_replace_exit); 54 MODULE_LICENSE("GPL"); 55 MODULE_INFO(livepatch, "Y"); 56 MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>"); 57 MODULE_DESCRIPTION("Livepatch test: atomic replace"); 58