/*
 * livepatch-sample.c - Kernel Live Patching Sample Module
 *
 * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/livepatch.h>

/*
 * This (dumb) live patch overrides the function that prints the
 * kernel boot cmdline when /proc/cmdline is read.
 *
 * Example:
 *
 * $ cat /proc/cmdline
 * <your cmdline>
 *
 * $ insmod livepatch-sample.ko
 * $ cat /proc/cmdline
 * this has been live patched
 *
 * $ echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
 * $ cat /proc/cmdline
 * <your cmdline>
 */

#include <linux/seq_file.h>
static int livepatch_cmdline_proc_show(struct seq_file *m, void *v)
{
	seq_printf(m, "%s\n", "this has been live patched");
	return 0;
}

static struct klp_func funcs[] = {
	{
		.old_name = "cmdline_proc_show",
		.new_func = livepatch_cmdline_proc_show,
	}, { }
};

static struct klp_object objs[] = {
	{
		/* name being NULL means vmlinux */
		.funcs = funcs,
	}, { }
};

static struct klp_patch patch = {
	.mod = THIS_MODULE,
	.objs = objs,
};

static int livepatch_init(void)
{
	int ret;

	ret = klp_register_patch(&patch);
	if (ret)
		return ret;
	ret = klp_enable_patch(&patch);
	if (ret) {
		WARN_ON(klp_unregister_patch(&patch));
		return ret;
	}
	return 0;
}

static void livepatch_exit(void)
{
	WARN_ON(klp_disable_patch(&patch));
	WARN_ON(klp_unregister_patch(&patch));
}

module_init(livepatch_init);
module_exit(livepatch_exit);
MODULE_LICENSE("GPL");
MODULE_INFO(livepatch, "Y");
/log/include/scsi/scsi_dh.h'>
<input type='hidden' name='id' value='17901e1bde9b959b535d075f137d5a86ca64f1c9'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?id=17901e1bde9b959b535d075f137d5a86ca64f1c9'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/include?id=17901e1bde9b959b535d075f137d5a86ca64f1c9'>include</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/scsi?id=17901e1bde9b959b535d075f137d5a86ca64f1c9'>scsi</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/scsi/scsi_dh.h?id=17901e1bde9b959b535d075f137d5a86ca64f1c9'>scsi_dh.h</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/include/scsi/scsi_dh.h?id=17901e1bde9b959b535d075f137d5a86ca64f1c9&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>