kpatch/kmod/patch/kpatch-patch-hook.c

78 lines
2.1 KiB
C

/*
* Copyright (C) 2013 Josh Poimboeuf <jpoimboe@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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
* 02110-1301, USA.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include "kpatch.h"
#include "kpatch-patch.h"
extern char __kpatch_patches, __kpatch_patches_end;
static struct kpatch_func *funcs;
static int num_funcs;
static int __init patch_init(void)
{
struct kpatch_patch *patches;
int i;
patches = (struct kpatch_patch *)&__kpatch_patches;
num_funcs = (&__kpatch_patches_end - &__kpatch_patches) /
sizeof(*patches);
funcs = kmalloc(num_funcs * sizeof(*funcs), GFP_KERNEL);
if (!funcs)
return -ENOMEM;
for (i = 0; i < num_funcs; i++) {
funcs[i].old_addr = patches[i].old_addr;
funcs[i].old_size = patches[i].old_size;
funcs[i].new_addr = patches[i].new_addr;
}
return kpatch_register(THIS_MODULE, funcs, num_funcs);
}
static void __exit patch_exit(void)
{
int ret;
ret = kpatch_unregister(THIS_MODULE, funcs, num_funcs);
if (ret) {
/*
* TODO: If this happens, we're screwed. We need a way to
* prevent the module from unloading if the activeness safety
* check fails.
*
* Or alternatively we could keep trying the activeness safety
* check in a loop, until it works or we timeout. Then we
* could panic.
*/
panic("kpatch_unregister failed: %d", ret);
}
kfree(funcs);
}
module_init(patch_init);
module_exit(patch_exit);
MODULE_LICENSE("GPL");