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70 lines
1.3 KiB
70 lines
1.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* livepatch-sample.c - Kernel Live Patching Sample Module |
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* |
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* Copyright (C) 2014 Seth Jennings <[email protected]> |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/livepatch.h> |
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/* |
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* This (dumb) live patch overrides the function that prints the |
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* kernel boot cmdline when /proc/cmdline is read. |
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* |
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* Example: |
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* |
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* $ cat /proc/cmdline |
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* <your cmdline> |
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* |
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* $ insmod livepatch-sample.ko |
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* $ cat /proc/cmdline |
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* this has been live patched |
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* |
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* $ echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled |
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* $ cat /proc/cmdline |
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* <your cmdline> |
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*/ |
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#include <linux/seq_file.h> |
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static int livepatch_cmdline_proc_show(struct seq_file *m, void *v) |
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{ |
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seq_printf(m, "%s\n", "this has been live patched"); |
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return 0; |
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} |
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static struct klp_func funcs[] = { |
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{ |
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.old_name = "cmdline_proc_show", |
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.new_func = livepatch_cmdline_proc_show, |
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}, { } |
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}; |
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static struct klp_object objs[] = { |
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{ |
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/* name being NULL means vmlinux */ |
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.funcs = funcs, |
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}, { } |
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}; |
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static struct klp_patch patch = { |
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.mod = THIS_MODULE, |
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.objs = objs, |
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}; |
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static int livepatch_init(void) |
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{ |
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return klp_enable_patch(&patch); |
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} |
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static void livepatch_exit(void) |
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{ |
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} |
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module_init(livepatch_init); |
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module_exit(livepatch_exit); |
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MODULE_LICENSE("GPL"); |
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MODULE_INFO(livepatch, "Y");
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