Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * livepatch-sample.c - Kernel Live Patching Sample Module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/livepatch.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * This (dumb) live patch overrides the function that prints the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * kernel boot cmdline when /proc/cmdline is read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  * $ cat /proc/cmdline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  * <your cmdline>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * $ insmod livepatch-sample.ko
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * $ cat /proc/cmdline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * this has been live patched
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  * $ echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * $ cat /proc/cmdline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  * <your cmdline>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) static int livepatch_cmdline_proc_show(struct seq_file *m, void *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	seq_printf(m, "%s\n", "this has been live patched");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static struct klp_func funcs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 		.old_name = "cmdline_proc_show",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 		.new_func = livepatch_cmdline_proc_show,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	}, { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static struct klp_object objs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 		/* name being NULL means vmlinux */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		.funcs = funcs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	}, { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static struct klp_patch patch = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	.mod = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	.objs = objs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) static int livepatch_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 	return klp_enable_patch(&patch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) static void livepatch_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) module_init(livepatch_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) module_exit(livepatch_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) MODULE_INFO(livepatch, "Y");